20-F/A

As filed with the Securities and Exchange Commission on May 9, 2018

UNITED STATES SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

Form 20-F/A

(Amendment No. 1)

ANNUAL REPORT PURSUANT TO SECTION 13 OR 15(d)OF THE SECURITIES EXCHANGE ACT OF 1934

For the fiscal year ended: December 31, 2017
Commission file number: 001-38256

NEXA RESOURCES S.A.

(Exact name of Registrant as specified in its charter)

Grand Duchy of Luxembourg

(Jurisdiction of incorporation or organization)

Mario Antonio Bertoncini

Senior Vice President Finance and Chief Financial Officer
Phone: +352 26 00 53 43
26-28 rue Edward Steichen
L-2540, Luxembourg
Grand Duchy of Luxembourg
(Address of principal executive offices)

Securities registered or to be registered pursuant to Section 12(b) of the Act:

Title of Each Class	Name of Each Exchange on Which Registered
Common shares, each with par value of US$1.00	New York Stock Exchange

Securities registered or to be registered pursuant to Section 12(g) of the Act: None
Securities for which there is a reporting obligation pursuant to Section 15(d) of the Act: None
The number of outstanding shares of each class of stock of Nexa as of December 31, 2017 was:

133,320,513 common shares, each with par value of US$1.00

Indicate by check mark if the registrant is a well-known seasoned issuer, as defined in Rule 405 of the Securities Act.

Yes o  No x

If this report is an annual or transition report, indicate by check mark if the registrant is not required to file reports pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934.

Yes o  No x

Indicate by check mark whether the registrant (1) has filed all reports required to be filed by Section 13 or 15(d) of the Securities Exchange Act of 1934 during the preceding 12 months (or for such shorter period that the registrant was required to file such reports) and (2) has been subject to such filing requirements for the past 90 days.

Yes x  No o

Indicate by check mark whether the registrant has submitted electronically and posted on its corporate website, if any, every Interactive Data File required to be submitted and posted pursuant to Rule 405 of Regulation S-T (§232.405 of this chapter) during the preceding 12 months (or for such shorter period that the registrant was required to submit and post such files).

Yes x  No o

Indicate by check mark whether the registrant is a large accelerated filer, an accelerated filer, a non-accelerated filer or an emerging growth company. See definition of “accelerated filer,” “large accelerated filer” and “emerging growth company” in Rule 12b-2 of the Exchange Act. (Check one):

Large accelerated filer o Accelerated filer o Non-accelerated filer x Emerging growth company o

If an emerging growth company that prepares its financial statements in accordance with U.S. GAAP, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 13(a) of the Exchange Act. o

Indicate by check mark which basis of accounting the registrant has used to prepare the financial statements included in this filing:

U.S. GAAP o    International Financial Reporting Standards as issued by the International Accounting Standards Board x   Other o

If “Other” has been checked in response to the previous question, indicate by check mark which financial statement item the registrant has elected to follow.

Item 17 o Item 18 o

If this is an annual report, indicate by check mark whether the registrant is a shell company (as defined in Rule 12b-2 of the Exchange Act).

Yes o  No x

Explanatory Note

This Amendment No. 1 to the Annual Report on Form 20-F (“Amendment No. 1”) of Nexa Resources S.A. (the “Company”) amends the Company’s Annual Report on Form 20-F for the fiscal year ended December 31, 2017 (the “Original 20-F”), which was filed with the Securities and Exchange Commission on April 30, 2018. The Company is filing this Amendment No. 1 solely for the purposes of adding Exhibit 101 to Item 19 “Exhibits,” which was not included in the Original 20-F, and to furnish the Interactive Data File disclosure as Exhibit 101 in accordance with Rule 405 of Regulation S-T.

Except as described above, this Amendment No. 1 does not amend any information set forth in the Original 20-F, and the Company has not updated disclosures included therein to reflect any events that occurred subsequent to April 30, 2018.

2

PART III

ITEM 19. EXHIBITS

Exhibit Number	Description
101.INS	XBRL Instance Document
101.SCH	XBRL Taxonomy Extension Schema Document
101.CAL	XBRL Taxonomy Extension Calculation Linkbase Document
101.DEF	XBRL Taxonomy Extension Definition Linkbase Document
101.LAB	XBRL Taxonomy Extension Label Linkbase Document
101.PRE	XBRL Taxonomy Extension Presentation Linkbase Document

3

SIGNATURES

The registrant hereby certifies that it meets all of the requirements for filing on Form 20-F and that it has duly caused and authorized the undersigned to sign this Amendment No. 1 to the annual report on Form 20-F on its behalf.

NEXA RESOURCES S.A.
By:	/s/ Tito Botelho Martins Junior
	Name:	Tito Botelho Martins Junior
	Title:	Chief Executive Officer

By:	/s/ Mario Antonio Bertoncini
	Name: Mario Antonio Bertoncini
	Title:   Senior Vice President Finance and Chief Financial Officer

Date: May 9, 2018

4

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Document and Entity Information	12 Months Ended
	Dec. 31, 2017 shares
Document and Entity Information [Abstract]
Entity Registrant Name	Nexa Resources S.A.
Entity Central Index Key	0001713930
Document Type	20-F
Document Period End Date	Dec. 31, 2017
Amendment Flag	false
Current Fiscal Year End Date	--12-31
Entity Well-known Seasoned Issuer	No
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Filer Category	Non-accelerated Filer
Entity Common Stock, Shares Outstanding	133,320,513
Document Fiscal Year Focus	2017
Document Fiscal Period Focus	FY

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Consolidated balance sheet - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Current assets
Cash and cash equivalents	$ 1,019,037	$ 915,576
Financial investments	206,155	116,957
Derivative financial instruments	7,483	20,740
Trade accounts receivable	182,713	120,062
Inventory	324,878	291,768
Taxes recoverable	80,134	102,996
Other assets	18,507	23,716
Total current assets other than assets held for sale	1,838,907	1,591,815
Assets held for sale		252
Total current assets	1,838,907	1,592,067
Non-current assets
Financial investments	392	2,541
Derivative financial instruments	4,294
Related parties	738	400,798
Judicial deposits	10,949	14,160
Deferred taxes	224,513	221,304
Taxes recoverable	32,510	26,736
Other assets	29,679	21,010
Investments in associates	309	323
Property, plant and equipment	1,996,514	1,978,462
Intangible assets	1,822,719	1,903,152
Total non-current assets	4,122,617	4,568,486
Total assets	5,961,524	6,160,553
Current liabilities
Loans and financing	40,841	62,601
Derivative financial instruments	12,588	37,458
Trade payables	329,814	282,241
Confirming payable	111,024	102,287
Salaries and payroll charges	79,798	70,022
Taxes payable	41,109	29,848
Advances from customers	800	2,894
Use of public assets	1,649	1,663
Dividends payable	4,138	7,185
Related parties	87,686	222,917
Provisions	14,641
Deferred revenue	31,296	37,980
Other liabilities	12,831	18,777
Total current liabilities	768,215	875,873
Non-current liabilities
Loans and financing	1,406,458	1,081,784
Derivative financial instruments	2,449
Related parties	2,238	7,596
Provisions	326,520	296,879
Deferred taxes	324,931	328,608
Use of public assets	22,660	24,257
Deferred revenue	190,589	212,020
Other liabilities	8,561	9,220
Total non-current liabilities	2,284,406	1,960,364
Total liabilities	3,052,621	2,836,237
Shareholders' equity
Capital	133,320	1,041,416
Share premium	1,123,755	339,228
Reserves	1,318,728	1,678,456
Cumulative deficit	(11,612)	(138,043)
Accumulated other comprehensive loss	(77,356)	(73,085)
Total equity attributable to owners of the parent	2,486,835	2,847,972
Non-controlling interests	422,068	476,344
Total shareholders' equity	2,908,903	3,324,316
Total liabilities and shareholders' equity	$ 5,961,524	$ 6,160,553

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Consolidated income statement - USD ($) shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Consolidated income statement
Net revenue from products sold	$ 2,449,484	$ 1,964,841	$ 1,865,183
Cost of products sold	(1,681,202)	(1,439,101)	(1,463,290)
Gross profit	768,282	525,740	401,893
Operating expenses
Selling	(89,239)	(90,647)	(84,559)
General and administrative	(148,242)	(127,305)	(106,299)
Other operating expenses, net	(129,221)	(177,819)	(47,105)
Total operating expenses	(366,702)	(395,771)	(237,963)
Operating profit before equity results and net financial results	401,580	129,969	163,930
Net financial results
Financial income	29,868	24,955	19,268
Financial expenses	(106,169)	(70,374)	(61,625)
Exchange variation gains (losses), net	(53,880)	124,500	(299,574)
Finance results, net	(130,181)	79,081	(341,931)
Results of investees
Share in the results of associates	60	(158)	(256)
Profit (loss) before taxation	271,459	208,892	(178,257)
Taxes on income
Current	(125,691)	(75,282)	(62,758)
Deferred	19,497	(23,101)	101,537
Profit (loss) for the year from continuing operations	165,265	110,509	(139,478)
Discontinued operations			(318)
Profit (loss) for the year	165,265	110,509	(139,796)
Profit (loss) attributable to the owners of the parent	126,885	93,167	(129,461)
Profit (loss) attributable to non-controlling interests	$ 38,380	$ 17,342	$ (10,335)
Average number of shares	116,527	80,699	1,874
Basic and diluted earnings (loss) per share (in dollars per share)	$ 1.09	$ 1.15	$ (69.08)

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Consolidated statement of comprehensive income - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Consolidated statement of comprehensive income
Profit (loss) for the year	$ 165,265	$ 110,509	$ (139,796)
Other comprehensive income (loss) net of taxes, all of which can be reclassified to the income statement
Operating cash flow hedge accounting	12,556	(16,256)	5,832
Currency translation of foreign subsidiaries	(10,742)	30,373	(74,163)
Total other comprehensive income (loss) net of taxes, all of which can be reclassified to the income statement	1,814	14,117	(68,331)
Other comprehensive income net of taxes, all of which cannot be reclassified to the statement of operations
Remeasurements of retirement benefits			535
Total comprehensive income (loss) for the year	167,079	124,626	(207,592)
Comprehensive income (loss) attributable to the owners of the parent	125,941	101,199	(165,136)
Comprehensive income (loss) attributable to non-controlling interests	$ 41,138	$ 23,427	$ (42,456)

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Consolidated statement of changes in equity - USD ($) $ in Thousands	Votorantim Investimentos Latino-Americanos S.A. - "VILA" Total	Votorantim Investimentos Latino-Americanos S.A. - "VILA" Reserves	Votorantim Investimentos Latino-Americanos S.A. - "VILA"	Nexa Resources Atacocha S.A.A. - "NEXA ATACOCHA" (formely Compania Minera Atacocha S.A.A.) Total	Nexa Resources Atacocha S.A.A. - "NEXA ATACOCHA" (formely Compania Minera Atacocha S.A.A.) Reserves	Nexa Resources Atacocha S.A.A. - "NEXA ATACOCHA" (formely Compania Minera Atacocha S.A.A.) Non-controlling interests	Nexa Resources Atacocha S.A.A. - "NEXA ATACOCHA" (formely Compania Minera Atacocha S.A.A.)	NEXA PERU Total	NEXA PERU Reserves	NEXA PERU Cumulative deficit	NEXA PERU Non-controlling interests	NEXA PERU	NEXA BR Total	NEXA BR Reserves	NEXA BR	Pollarix S. A. Non-controlling interests	Pollarix S. A.	Total	Capital	Share premium	Reserves	Cumulative deficit	Accumulated other comprehensive income	Non-controlling interests	Total
Beginning balance at Dec. 31, 2014																		$ 2,654,051	$ 1,280,421		$ 1,468,456	$ (49,384)	$ (45,442)	$ 1,222,317	$ 3,876,368
Total comprehensive income for the year
Profit for the year																		(129,461)				(129,461)		(10,335)	(139,796)
Other components of comprehensive income (loss) for the year																		(35,675)					(35,675)	(32,121)	(67,796)
Total comprehensive income (loss) for the year																		(165,136)				(129,461)	(35,675)	(42,456)	(207,592)
Total contributions by and distributions to shareholders
Repurchase of shares								$ 98,655	$ 98,655		$ (216,252)	$ (117,597)
Changes in non-controlling interests				$ 1,099	$ 1,099	$ (2,487)	$ (1,388)	(4,738)	(4,738)		(3,151)	(7,889)	$ 52,686	$ 52,686	$ 52,686
Dividend distribution																		(51,322)				(51,322)		(14,875)	(66,197)
Capital and share premium increase (including Initial Public Offering)																		84	84						84
Total contributions by and distributions to shareholders																		96,464	84		147,702	(51,322)		(236,765)	(140,301)
Ending balance at Dec. 31, 2015																		2,585,379	1,280,505		1,616,158	(230,167)	(81,117)	943,096	3,528,475
Total comprehensive income for the year
Profit for the year																		93,167				93,167		17,342	110,509
Other components of comprehensive income (loss) for the year																		8,032					8,032	6,085	14,117
Total comprehensive income (loss) for the year																		101,199				93,167	8,032	23,427	124,626
Total contributions by and distributions to shareholders
Repurchase of shares								22,902	22,986	$ (84)	(54,154)	(31,252)
Energy assets retention/compensation																		(52,847)			(52,847)				(52,847)
Constitution of share premium																			(350,000)	$ 350,000
Reimbursement of share premium																		(69,931)		(69,931)					(69,931)
Changes in non-controlling interests	$ (6,819)	$ (6,819)	$ (6,819)			$ (2,635)	$ (2,635)	$ 253,331	$ 253,331		$ (423,994)	$ (170,663)
Dividend distribution																		(959)				(959)		(9,396)	(10,355)
Capital and share premium increase (including Initial Public Offering)																		170,070	110,911	59,159					170,070
Put option of shares																		(170,070)			(170,070)				(170,070)
Cancellation of the loan due by NEXA BR to VSA													15,717	15,717	15,717
Total contributions by and distributions to shareholders																		161,394	(239,089)	339,228	62,298	(1,043)		(490,179)	(328,785)
Ending balance at Dec. 31, 2016																		2,847,972	1,041,416	339,228	1,678,456	(138,043)	(73,085)	476,344	3,324,316
Total comprehensive income for the year
Profit for the year																		126,885				126,885		38,380	165,265
Other components of comprehensive income (loss) for the year																		(944)				3,327	(4,271)	2,758	1,814
Total comprehensive income (loss) for the year																		125,941				130,212	(4,271)	41,138	167,079
Total contributions by and distributions to shareholders
Reversion of Put Option																		173,734			173,734				173,734
Energy assets retention/compensation																		(87,711)			(87,711)				(87,711)
Purchase of Pollarix																		(81,615)			(81,615)				(81,615)
Constitution of share premium																			(928,596)	928,596
Reimbursement of share premium																		(430,000)		(430,000)					(430,000)
Changes in non-controlling interests	$ (374,108)	$ (374,108)	$ (374,108)										$ 7,911	$ 7,911	$ 7,911	$ (38,280)	$ (38,280)
Increase in participation in associates																		2,061			2,061			(2,061)
Dividend distribution																		(3,781)				(3,781)		(55,073)	(58,854)
Capital and share premium increase (including Initial Public Offering)																		306,431	20,500	285,931					306,431
Total contributions by and distributions to shareholders																		(487,078)	(908,096)	784,527	(359,728)	(3,781)		(95,414)	(582,492)
Ending balance at Dec. 31, 2017																		$ 2,486,835	$ 133,320	$ 1,123,755	$ 1,318,728	$ (11,612)	$ (77,356)	$ 422,068	$ 2,908,903

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Consolidated statement of cash flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Cash flow from operating activities
Profit (loss) before taxation	$ 271,459	$ 208,892	$ (178,257)
Results of investees - Discontinued operations			(318)
Adjustments to reconcile profit to cash
Interest, indexation and exchange variations	52,287	(96,766)	326,287
Share in the results of investees	(60)	158	574
Depreciation and amortization	270,454	275,034	295,258
Loss on sale of property, plant and equipment and intangible assets	694	552	3,443
Gain on sale of investment	(4,588)	(408)
Impairment (reversal) of property, plant and equipment and other assets	73	(979)	8,574
Provisions	32,672	93,701	(12,209)
Decrease (increase) in assets
Trade accounts receivable	(63,172)	(54,188)	56,293
Inventory	(15,675)	(62,586)	65,885
Other taxes recoverable	17,088	9,558	58,528
Other assets	6,168	(414)	(1,344)
Increase (decrease) in liabilities
Trade payables	47,573	9,557	21,790
Confirming payables	8,737	5,743	(22,672)
Salaries and payroll charges	9,776	25,206	(17,118)
Taxes payable	(14,165)	(15,375)	(76,149)
Deferred revenue	(36,299)	250,000
Other liabilities	(45,183)	13,566	(22,913)
Interest paid	(58,635)	(37,321)	(39,672)
Taxes on income paid	(100,265)	(38,869)	(51,384)
Net cash provided by operating activities	378,939	585,061	414,596
Cash flow from investing activities
Financial investments	(65,661)	(47,749)	(25,460)
Acquisitions of property, plant and equipment	(196,717)	(180,856)	(183,176)
Acquisitions of intangible assets	(921)	(2,133)	(3,891)
Loan repayment received from related parties		10,284	10,059
Acquisition of Pollarix	(81,615)
Related parties		6,248	44,785
Proceeds from sale of non-current assets	16,542	12,787	1,027
Net cash used in investing activities	(328,372)	(201,419)	(156,656)
Cash flow from financing activities
New loans and financing	830,598	550,966	23,454
Payments of loans and financing	(537,254)	(483,100)	(280,717)
Dividends paid	(61,549)	(59,660)	(13,345)
Reimbursement share premium	(430,000)	(69,931)
Capital increase - Initial public offering	20,500	170,070	84
Share premium -Initial public offering	285,931
Related parties		3,967	(41,171)
Energy assets compensation payment - Related parties	(55,380)		52,686
Net cash provided by (used in) financing activities	52,846	(92,238)	(385,883)
Effects of exchange rates on cash and cash equivalents	48	2,757	(1,321)
Increase (decrease) in cash and cash equivalents	103,461	294,161	(129,264)
Cash and cash equivalents at the beginning of the year	915,576	621,415	750,679
Cash and cash equivalents at the end of the year	$ 1,019,037	915,576	621,415
NEXA PERU
Cash flow from financing activities
Repurchase of shares		(31,252)	(117,597)
Decrease in non-controlling interests		(170,663)	(7,889)
Nexa Resources Atacocha S.A.A. - "NEXA ATACOCHA" (formely Compania Minera Atacocha S.A.A.)
Cash flow from financing activities
Decrease in non-controlling interests		$ (2,635)	$ (1,388)

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General information

12 Months Ended

Dec. 31, 2017

General information

General information

1General information

Nexa Resources S.A. (“NEXA” or the “Company” or the “parent”) was incorporated on February 26, 2014 under the laws of Luxembourg as a public limited liability company (société anonyme). The Company’s registered office is located in the city of Luxembourg in the Grand Duchy of Luxembourg.

The Company’s controlling shareholder is Votorantim S.A. (“VSA”), which holds 64.25% of its equity. VSA is a Brazilian privately owned industrial conglomerate that holds ownership interests in metal, steel, cement, energy and pulp companies, among others.

The Company operates in the mining and smelting segments, principally engaged in zinc content production. The Company also produces copper, lead, silver and gold, which are byproducts of zinc production. The Company’s mining segment is comprised of five mines located in Peru and Brazil, which operates primarily through its subsidiaries NEXA BR (as defined below) and NEXA PERU (as defined below). The Company’s smelting segment is comprised of three assets, one located in Peru and two in Brazil, that operates through its subsidiaries NEXA BR (as defined below) and NEXA CJM (as defined below). The information on the Company structure is provided in note 2.1 (a).

On December 18th, 2017, the shareholders of subsidiary Compañia Minera Milpo S.A.A approved the change of its corporate name to Nexa Resources Perú S.A.A. This change is still in process of being formalized before the Peruvian Public Registry. Given that such change has been duly approved by Compañia Minera Milpo S.A.A shareholders, the Company refers to this subsidiary herein as “NEXA PERU”.

On December 18th, 2017, the shareholders of subsidiary Compañia Minera Atacoccha S.A.A approved the change of its corporate name to Nexa Resources Atacocha S.A.A. This change is still in process of being formalized before the Peruvian Public Registry. Given that such change has been duly approved by Compañia Minera Atacoccha S.A.A shareholders, the Company refers to this subsidiary herein as “NEXA ATACOCHA”.

On December 4th, 2017, the shareholders of subsidiary Votorantim Metais — Cajamarquilla S.A. approved the change of its corporate name to Nexa Resources Cajamarquilla S.A. This change is still in process of being formalized before the Peruvian Public Registry. Given that such change has been duly approved by Votorantim Metais — Cajamarquilla S.A. shareholders, the Company refers to this subsidiary herein as “NEXA CJM”.

On November 16th, 2017, the Board of subsidiary Milpo UK Ltd. approved the change of its corporate name to Nexa Resources UK Ltd. This change is still in process of being formalized before the UK Public Registry (Companies House). Given that such change has been already approved by Milpo UK Ltd. Board and its shareholders, the Company refers to this subsidiary herein as “NEXA UK”.

On November 13th, 2017, the shareholders of subsidiary Votorantim Metais Zinco S.A. approved the change of its corporate name to Nexa Recursos Minerais S.A. This change has been submitted to the approval of the National Defense Office (Conselho de Defesa Nacional - CDN) as Votorantim Metais Zinco S.A. possesses mineral rights in border areas. After receiving the CDN’s approval, same corporate act will be submitted to the Brazilian Public Registry. Given that such change has been duly approved by Votorantim Metais Zinco S.A. shareholders, the Company refers to this subsidiary herein as “NEXA BR”.

Main transactions for the year ended December 31, 2017

(i)Transfer of Export Prepayments

In February 2017, Companhia Brasileira de Alumínio (“CBA”) transferred its Export Prepayments (advances received from banks to finance future exports) amounting to US$ 100,000 and US$ 290,000 to NEXA BR, a wholly-owned subsidiary of NEXA, with the consent of the operation’s counterparties, NEXA and Votorantim GmbH (“VGmbH”), respectively. The amount net of transaction costs is US$ 389,471.

Due to the transfer, CBA became a debtor of NEXA BR by an amount of US$ 389,471 (R$ 1,215,489 thousand) denominated in Brazilian Reais at February 2017. CBA’s debt, including the export prepayments of US$ 367,417 (R$ 1,215,489 thousand) and other payables of US$ 10,244, was liquidated in June 2017 through the transfer from CBA to NEXA BR of property, plant and equipment amounting to US$ 2,848, intangible assets amounting to US$ 705 and 25.80% of the participation in Votorantim Investimentos Latino-Americanos S.A. (“VILA”), amounting to US$ 374,108, which impacted the Equity line item since VILA is a fully consolidated subsidiary.  This was a non-cash transaction and the difference between the amounts in US dollars is related to foreign exchange variation.

(ii)Bond issuance

On May 4, 2017, the Company issued an aggregate principal amount of US$ 700,000 in unsecured bonds set to mature in 2027 at an interest rate of 5.375% per year. The proceeds from this offering were used to repay a portion of existing consolidated debt with banks, thereby extending the maturity of outstanding debt. These securities are guaranteed by NEXA BR, NEXA PERU and NEXA CJM.

(iii)Energy Assets compensation payment

On May 19, 2017, VILA issued new shares subscribed by NEXA BR, amounting to R$ 129,187 thousand (US$ 39,827). The shares were fully subscribed through cash contributions.

On May 31, 2017, VILA executed a capital reduction transaction whereby it transferred cash to VSA in the amount of R$ 129,187 thousand (US$ 39,827).

On May 31, 2017, NEXA BR paid in cash the remaining balance of Energy Assets compensation, as mentioned on note 1 (vii), to VSA in the amount of R$ 50,450 thousand (US$ 15,553).

(iv)Conversion of share capital into share premium

The Company approved the conversion of share capital into share premium in the amount of US$ 200,000 in June 2017, US$ 300,000 in September 2017 and US$ 428,596 in October 2017.

(v)Reimbursement of share premium

The Company approved the reimbursement of share premium to its shareholders amounting to US$ 140,000 in June 2017, US$ 140,000 in September 2017 and US$ 150,000 in October 2017. All payments were proportional with their participations.

(vi)Put option reversion

During 2016, the Company granted to the minority shareholders a Put Option over their stake in the Company’s capital. The Company determined that, as the Put Option could be exercised in the event of certain change of control which could be out of the control of the Company, the option met the criteria under IAS 32 for recognition as a liability and corresponding equity reserve.

In June 2017, a new agreement was signed between NEXA’s shareholders, and the liability of the put option that had been granted by the Company to the minority shareholders was transferred to VSA, the Company’s controlling shareholder. Since VSA was at that moment the grantor of the put option amounting US$ 173,734, NEXA derecognized the liability as of June 30, 2017 against Shareholders’ Equity. This was a non-cash transaction.

Due to the closing of the Company’s initial public offering (note 1(x)), the Option expired.

(vii)Energy Assets

In the period from April 2016 to June 2017, the Company had a liability with its controlling shareholder VSA for the right to use the energy generation assets (the “Energy Assets”), owned by Nexa BR. On June 30, 2017, under the amended shareholders agreement, NEXA received all of the Energy Assets, has no further obligation with VSA to compensate for the right to use the Energy Assets, and acquired one third of the total outstanding share capital, representing 100% of ordinary shares with voting rights and control over Pollarix S.A. (“Pollarix”) (formerly denominated as “Holding B Company”). The remaining two thirds, representing 100% of preferred shares with limited voting and non-controlling rights are held by VSA and its subsidiaries.

Pollarix is a holding company with 20.98% interest in Campos Novos Energia S.A. (“Enercan”) (another energy producing joint operation). NEXA agreed to pay to CBA US$ 81,620 (R$ 270,000 thousand) for one third of Pollarix shares, of which US$ 59,549 (R$ 197,000 thousand) was paid in June 2017 and US$ 22,277 (R$ 73,000 thousand) was paid in October 2017. The difference between the amounts in US dollars is related to foreign exchange variation.

The impact on NEXA consolidated financial statements are: (a) NEXA will hold a 1/3 (one third) interest (all ordinary shares) in Pollarix and VSA and its subsidiaries will hold 2/3 (two-thirds) interest (all preferred shares), the latter of which have limited voting rights and are entitled to dividends per share equal to 1.25 times the dividends per share payable on the ordinary shares, (b) NEXA BR will contribute the Energy Assets to Pollarix, issuing new ordinary and preferred shares, (c) NEXA BR will spin off all of the new issued preferred shares of Pollarix to VSA, (d) NEXA BR will have its capital reduced by US$ 87,666 (R$ 290,000 thousand) paid in cash to VSA, and (e) NEXA will hold a 100% participation in NEXA BR and VILA, previously held by VSA. All of these transactions are considered to be under common control of VSA with a net impact in the Company’s shareholders equity. In accordance with the Company’s accounting policy for common control transaction, as the Energy Assets are consolidated retroactively, the liability with VSA from April 2016 until June 2017, has been eliminated from the consolidated income statement and no gain or loss is recorded as a result of this transaction.

Additionally, the non-controlling interest participations held by VSA and its subsidiaries as of December 31, 2017 relating to Pollarix S.A. (67%), NEXA BR (0%) and VILA (0%) has been reflected retroactively in these consolidated financial statements.

In order to fully implement step (b), transfer of Energy Assets is subject to the prior consent of the Brazilian Electricity Regulatory Agency (“ANEEL”). Management believes that such consent is perfunctory, based on precedents in similar cases and on the fact that the Energy Assets belong to the same economic group. Such consent is expected to occur during the first quarter of 2018.

(viii)Capital increase

The Company approved a capital increase of US$ 63,216 in July and capital increase of US$ 137,176 in October 2017 for its subsidiary NEXA BR, of which US$ 19,176 was paid by VSA.

(ix)Dividend distribution

On September 19, 2017, the Board of Directors of NEXA PERU approved a dividend payment of US$ 335,001 to its shareholders, proportional with such shareholders’ participations. US$ 55,073 was paid to NEXA PERU’s non-controlling shareholders on October 16, 2017.

(x)Initial public offering

On October 27, 2017, the Company announced the pricing of its initial public offering. That same day, its common shares began trading on the New York Stock Exchange (NYSE) and the Toronto Stock Exchange (TSX), under the ticker symbol “NEXA”.

On October 31, 2017, the Company announced the closing of its initial public offering of 35,650,000 of the Company’s common shares at a public offering price of US$16.00 per share, which included an aggregate of 15,150,000 shares sold by VSA (including pursuant to the exercise in full by the underwriters of their over-allotment option for 4,650,000 shares).

As a consequence, the capital of the Company increased in US$ 20,500 related to the issuance of new shares. The remaining US$ 307,500 was designated as share premium constitution, reduced by US$ 21,569 related to underwriter expenses.

(xi)Capital reduction of Pollarix

On October 27, 2017, the subsidiary Pollarix decreased its share capital by US$ 57,134 (R$ 189,000 thousand), cancelling 81,818,181 ordinary shares and 163,636,364 preferred shares fully paid in cash to its then existing shareholder, CBA. The transaction decreased the Company’s Equity in the amount of US$ 38,280 as on the consolidated financial statements NEXA already has one third interest in Pollarix (Note 1 (vii)).

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Basis of preparation of the consolidated financial statements

12 Months Ended

Dec. 31, 2017

Basis of preparation of the consolidated financial statements

Basis of preparation of the consolidated financial statements

2Basis of preparation of the consolidated financial statements

The consolidated financial statements of the Company have been prepared in accordance with International Financial Reporting Standards (IFRS) and interpretations issued by the IFRS Interpretations Committee (IFRS IC) applicable to companies reporting under IFRS. The financial statements comply with IFRS as issued by the International Accounting Standards Board (IASB).

The consolidated financial statements have been prepared under the historical costs convention, modified for some financial assets and financial liabilities (including derivative instruments) measured at fair value through profit or loss (where applicable).

Changes resulting from new arrangements of the Company include the effects of the Energy Assets which were transferred to NEXA on June 30, 2017. The transfer of the Energy Assets is described in Note 1 (ii) and (vii), to these financial statements. As consequence of these arrangements the Company applied the common control concept retroactively as mentioned in Note 2.1 (b). NEXA has recognized the Energy Assets for all the years presented in these consolidated financial statements.

2.1Principles of consolidation and equity accounting

The following accounting policies are applied to the preparation of the consolidated financial statements.

(a)Subsidiaries

Subsidiaries include all entities over which NEXA has direct or indirect control. NEXA controls an entity when it is exposed to, or has the right to, variable returns from its involvement with the entity and the Company has the ability to affect those returns through its power over the entity. Subsidiaries are fully consolidated from the date on which control is transferred to the Company, except when the predecessor basis of accounting is applied. Subsidiaries are deconsolidated from the date on which that control ceases.

Transactions, balances and unrealized gains and losses between Group companies are eliminated.

The accounting policies of subsidiaries are adjusted where necessary to ensure consistency with the policies adopted by the Company.

Main companies included in the consolidated financial statements:

	Percentage of capital
	2017	2016	Headquarters	Control	Activities
Campos Novos Energia S.A. - “Enercan”	20.98	20.98	Brazil	Indirect	Energy
Capim Branco Energia	12.63	12.63	Brazil	Indirect	Energy
Cia . Minera Gaico S.A.	93.40	93.40	Peru	Indirect	Holding and others
Cia. Magistral S.A.C	100.00	—	Peru	Indirect	Holding and others
Cia. Minera Dona Isabel Ltda.	100.00	100.00	Peru	Indirect	Holding and others
Cia. Minera Shalipayco S.A.C	75.00	75.00	Peru	Indirect	Holding and others
Nexa Resources Atacocha S.A.A. - “NEXA ATACOCHA” (formely Compañia Minera Atacocha S.A.A.)	66.62	66.62	Peru	Indirect	Mining
Nexa Resources Perú S.A.A. - “NEXA PERU” (formely Compañia Minera Milpo S.A.A - “Milpo”)	80.23	80.23	Peru	Indirect	Mining
Consórcio UHE Igarapava	23.93	23.93	Brazil	Indirect	Energy
InPac Holding Limited	100.00	100.00	British Virgin Islands	Indirect	Holding and others
Inversiones Garza Azul S.A.C	100.00	100.00	Peru	Indirect	Holding and others
L.D.O.S.P.E. Empreendimentos e Participações Ltda.	100.00	—	Brazil	Indirect	Energy
L.D.Q.S.P.E. Empreendimentos e Participações Ltda.	100.00	—	Brazil	Indirect	Energy
L.D.R.S.P.E. Empreendimentos e Participações Ltda.	100.00	—	Brazil	Indirect	Energy
Nexa Resources El Porvenir S.A.C. (formely Milpo Andina Peru S.A.C.)	99.99	99.99	Peru	Indirect	Mining
Nexa Resources UK Ltd. - “NEXA UK” (formely Milpo UK Limited)	100.00	100.00	United Kingdom	Indirect	Mining
Minera Bongará S.A.	61.00	61.00	Peru	Indirect	Holding and others
Minera Cerro Colorado S.A.C	99.99	99.00	Peru	Indirect	Holding and others
Minera Chambará S.A.C	15.00	15.00	Peru	Indirect	Holding and others
Minera Pampa de Cobre S.A.C	99.99	99.00	Peru	Indirect	Mining
Minera Rayrock Ltda.	—	84.08	Chile	Indirect	Holding and others
Mineração Dardanelos Ltda.	70.00	70.00	Brazil	Indirect	Holding and others
Mineração Santa Maria Ltda.	99.99	99.99	Brazil	Indirect	Holding and others
Otavi Mining Investments (Pty) Ltd.	100.00	100.00	Namibia	Indirect	Holding and others
Otjitombo Mining Proprietary Ltd.	100.00	100.00	Namibia	Indirect	Holding and others
Pollarix S.A.	33.33	33.33	Brazil	Indirect	Holding and others
Rayrock Antofagasta S.A.C	99.99	100.00	Chile	Indirect	Holding and others
SMRL CMA nº 54	100.00	100.00	Peru	Indirect	Holding and others
SMRL Ltda. Pepita 1	57.50	57.50	Peru	Indirect	Holding and others
Votorantim Andina S.A. - “VASA”	99.99	99.99	Chile	Indirect	Holding and others
Votorantim GmbH	100.00	100.00	Austria	Direct	Holding and others
Votorantim Investimentos Latino-Americanos S.A. - “VILA”	100.00	100.00	Brazil	Indirect	Holding and others
Votorantim Metais Argentina S.A.	—	90.00	Argentina	Indirect	Holding and others
Votorantim Metais Bolívia S.R.L.	—	76.61	Bolivia	Indirect	Holding and others
Nexa Resources Cajamarquilla S.A. - “NEXA CJM” (formely Votorantim Metais Cajamarquilla S.A. - “CJM”)	99.99	99.99	Peru	Direct	Smelting
Nexa Recursos Minerais S.A. - “NEXA BR” (formely Votorantim Metais Zinco S.A. - “VMZ”)	100.00	100.00	Brazil	Direct	Mining / Smelting
Votorantim Metals Cananda Inc.	100.00	100.00	Canada	Indirect	Holding and others
Votorantim Metals Namibia Ltd.	100.00	100.00	Namibia	Indirect	Holding and others
Votorantim US. Inc.	100.00	100.00	United States	Direct	Holding and others

(b)Business combinations

The acquisition method of accounting is used for transactions classified as business combinations. The consideration transferred for the acquisition of a subsidiary is the fair value of the assets transferred, the liabilities assumed and the equity instruments issued. The consideration transferred includes the fair value of assets or liabilities resulting from a contingent consideration arrangement, when applicable. Acquisition-related costs are expensed as they are incurred. Identifiable assets acquired and liabilities assumed in a business combination are measured initially at their fair values at the acquisition date. The Company recognizes any non-controlling interest in the acquiree on an acquisition-by-acquisition basis, either at fair value or at the non-controlling interest’s proportionate share of the fair value of the acquiree’s identifiable net assets. The non-controlling interests to be recognized are determined upon each acquisition.

The excess of the consideration transferred, amount of any non-controlling interest in the acquired entity, and the acquisition-date fair value of any previous equity interest in the acquired entity over the fair value of the net identifiable assets acquired is recorded as goodwill. If those amounts are less than the fair value of the net identifiable assets of the subsidiary acquired, the difference is recognized directly in profit or loss as a bargain purchase.

Business combinations does not consider common control transactions.

(c)Foreign currency translation

(i)Functional and presentation currency

Items included in the consolidated financial statements of each of NEXA’s entities are measured using the currency of the primary economic environment in which the entity operates (the “functional currency”). The consolidated financial statements are presented in US Dollars (“US$”), which is NEXA’s functional and reporting currency.

(ii)Transactions and balances

Foreign currency transactions are translated into the functional currency using the exchange rates at the dates of the transactions. Foreign exchange gains and losses resulting from the settlement of such transactions and from the translation of monetary assets and liabilities denominated in foreign currencies at year end exchange rates are recognized in profit or loss. They are deferred in other comprehensive income if they relate to qualifying cash flow hedges.

Foreign exchange gains and losses that relate to cash and cash equivalents and borrowing are presented in the income statement, within finance income or expenses.

Non-monetary items that are measured at fair value in a foreign currency are translated using the exchange rates at the date when the fair value was determined. Translation differences on assets and liabilities carried at fair value are reported as part of the fair value gain or loss. For example, translation differences on non-monetary assets and liabilities such as equities held at fair value through profit or loss are recognized in profit or loss as part of the fair value gain or loss and translation differences on non-monetary assets such as equities classified as available-for-sale financial assets are recognized in other comprehensive income.

(iii)Group companies

The results and financial position of all of the Company’s entities (none of which has the currency of a hyper-inflationary economy) that have a functional currency different from the reporting currency are translated into the presentation currency as follows:

· Assets and liabilities for each balance sheet presented are translated at the closing rate at the date of that balance sheet;

· Income and expenses for each income statement, are translated at average exchange rates (unless this average is not a reasonable approximation of the cumulative effect of the rates prevailing on the transaction dates, in which case income and expenses are translated at the rates in force on the dates of the transactions); and

· All resulting exchange differences are recognized in other comprehensive income.

(d)Transactions with non-controlling interests

The Company treats transactions with non-controlling interests that do not result in a loss of control as transactions with the equity owners of the Company. A change in ownership interest results in an adjustment between the carrying amounts of the controlling and non-controlling interests to reflect their relative interests in the subsidiaries. Any difference between the amount of the adjustment to non-controlling interests and any consideration paid or received is recognized in a separate reserve within equity attributable to the owners.

2.2Revision of the Financial Statements

These financial statements are considered revised and restated, as the Company identified adjustments in its Consolidated Financial Statements for the years ended December 31, 2016 and 2015, previously publicly available.

The consolidated financial statements of NEXA and its subsidiaries for the year ended December 31, 2017 were authorized to be issued in accordance with a resolution of the Board of Directors on April 30,2018.

2.2.1 Intercompany Elimination

The revised information presented correct an error related to the intercompany elimination transaction on the sale of products between NEXA PERU and NEXA CJM. These sales were previously recorded considering the Gross Revenue amount recognized in NEXA PERU, which did not consider the taxes on sales. The corrections entries were made to remove the effects of intercompany transactions in the Consolidated Financial Statements related to the taxes on sales for the period ended December 31, 2016 and December 31, 2015.

The revision has no impact in the balance sheet, statement of comprehensive income, statement of changes in equity, net income and statements of cash flows.

The Company concluded that the adjustments, analyzed individually and in aggregate, in qualitative and quantitative terms, are not significant and material.

Therefore, the original, previously issued consolidated financial statements, and revised amounts are presented below:

a) Income Statement

	(Original) 2016		Adjustment		(Revised) 2016
Net revenue from products sold	1,912,813		52,028		1,964,841
Cost of products sold	(1,387,073	)	(52,028	)	(1,439,101	)
Gross profit	525,740		—		525,740

	(Original) 2015		Adjustment		(Revised) 2015
Net revenue from products sold	1,824,840		40,343		1,865,183
Cost of products sold	(1,422,947	)	(40,343	)	(1,463,290	)
Gross profit	401,893		—		401,893

b) Composition of net revenue

	(Original) 2016		Adjustment	(Revised) 2016
Gross Revenue	2,193,867		—	2,193,867
Taxes on sales and returns	(281,054	)	52,028	(229,026	)
Net revenue from products sold	1,912,813		52,028	1,964,841

	(Original) 2015		Adjustment	(Revised) 2015
Gross Revenue	2,072,439		—	2,072,439
Taxes on sales and returns	(247,599	)	40,343	(207,256	)
Net revenue from products sold	1,824,840		40,343	1,865,183

c) Revenue by destination

	(Original) 2016	Adjustment	(Revised) 2016
Peru	521,856	52,028	573,884
Brazil	560,878	—	560,878
United States	156,634	—	156,634
Luxembourg	100,631	—	100,631
Korea	66,887	—	66,887
Switzerland	59,873	—	59,873
Chile	67,546	—	67,546
Singapore	42,666	—	42,666
Germany	42,560	—	42,560
Colombia	39,137	—	39,137
Japan	36,005	—	36,005
Austria	22,982	—	22,982
Turkey	19,498	—	19,498
China	12,838	—	12,838
Italy	3,608	—	3,608
Other	159,214	—	159,214
	1,912,813	52,028	1,964,841

	(Original) 2015	Adjustment	(Revised) 2015
Peru	544,107	40,343	584,450
Brazil	534,141	—	534,141
United States	99,884	—	99,884
Luxembourg	98,159	—	98,159
Korea	51,181	—	51,181
Switzerland	135,450	—	135,450
Chile	52,865	—	52,865
Singapore	72,514	—	72,514
Germany	22,348	—	22,348
Colombia	42,007	—	42,007
Japan	32,994	—	32,994
Austria	18,731	—	18,731
Turkey	23,265	—	23,265
China	639	—	639
Italy	1,399	—	1,399
Other	95,156	—	95,156
	1,824,840	40,343	1,865,183

d) Revenue by currency

	(Original) 2016	Adjustment	(Revised) 2016
U.S. Dollar	1,362,964	52,028	1,414,992
Real	547,537	—	547,537
Other	2,312	—	2,312
	1,912,813	52,028	1,964,841

	(Original) 2015	Adjustment	(Revised) 2015
U.S. Dollar	1,294,535	40,343	1,334,878
Real	529,218	—	529,218.0
Other	1,087	—	1,087
	1,824,840	40,343	1,865,183

e) Expenses by nature

	(Original) 2016	Adjustment	(Revised) 2016
Raw materials and consumables used	904,881	52,028	956,909
Employee benefit expenses	233,755	—	233,755
Depreciation and amortization	275,034	—	275,034
Freight costs	68,962	—	68,962
Services, miscellaneous	89,426	—	89,426
Other Expenses	32,967	—	32,967
	1,605,025	52,028	1,657,053
Reconciliation
Cost of products sold	1,387,073	52,028	1,439,101
Selling expenses	90,647	—	90,647
General and administrative expenses	127,305	—	127,305
	1,605,025	52,028	1,657,053

	(Original) 2015	Adjustment	(Revised) 2015
Raw materials and consumables used	940,190	40,343	980,533
Employee benefit expenses	202,876	—	202,876
Depreciation and amortization	295,258	—	295,258
Freight costs	73,871	—	73,871
Services, miscellaneous	77,772	—	77,772
Other Expenses	23,838	—	23,838
	1,613,805	40,343	1,654,148
Reconciliation
Cost of products sold	1,422,947	40,343	1,463,290
Selling expenses	84,559	—	84,559
General and administrative expenses	106,299	—	106,299
	1,613,805	40,343	1,654,148

f) Information by business segment and geographic area — intersegment

	Original - 2016
	Mining		Smelting		Elimination		Adjustment		Total
Revenue from products sold - third parties	417,159		1,491,988		—		3,666		1,912,813
Intersegment revenues	490,266		—		(490,266	)	—		—
Total revenue	907,425		1,491,988		(490,266	)	3,666		1,912,813
Cost of products sold	(513,135	)	(1,260,519	)	490,266		(103,685	)	(1,387,073	)
Gross Profit	394,290		231,469		—		(100,019	)	525,740

	Revised - 2016
	Mining		Smelting		Elimination		Adjustment		Total
Revenue from products sold - third parties	469,187		1,491,988		—		3,666		1,964,841
Intersegment revenues	438,238		—		(438,238	)	—		—
Total revenue	907,425		1,491,988		(438,238	)	3,666		1,964,841
Cost of products sold	(513,135	)	(1,260,519	)	438,238		(103,685	)	(1,439,101	)
Gross Profit	394,290		231,469		—		(100,019	)	525,740

	Original - 2015
	Mining		Smelting		Elimination		Adjustment		Total
Revenue from products sold - third parties	380,320		1,421,307		—		23,213		1,824,840
Intersegment revenues	390,384		—		(390,384	)	—		—
Total revenue	770,704		1,421,307		(390,384	)	23,213		1,824,840
Cost of products sold	(532,097	)	(1,170,545	)	390,384		(110,689	)	(1,422,947	)
Gross Profit	238,607		250,762		—		(87,476	)	401,893

	Revised - 2015
	Mining		Smelting		Elimination		Adjustment		Total
Revenue from products sold - third parties	420,663		1,421,307		—		23,213		1,865,183
Intersegment revenues	350,041		—		(350,041	)	—		—
Total revenue	770,704		1,421,307		(350,041	)	23,213		1,865,183
Cost of products sold	(532,097	)	(1,170,545	)	350,041		(110,689	)	(1,463,290	)
Gross Profit	238,607		250,762		—		(87,476	)	401,893

g) Information by business segment and geographic area - revenue by geographic area

	Original - 2016
	Net revenue from products sold	Cost of products sold		Gross profit
Brazil	714,946	(473,006	)	241,940
Peru	1,178,354	(896,940	)	281,414
Holding	19,513	(17,127	)	2,386
Total	1,912,813	(1,387,073	)	525,740

	Revised - 2016
	Net revenue from products sold	Cost of products sold		Gross profit
Brazil	714,946	(473,006	)	241,940
Peru	1,230,382	(948,967	)	281,415
Holding	19,513	(17,128	)	2,385
Total	1,964,841	(1,439,101	)	525,740

	Original - 2015
	Net revenue from products sold	Cost of products sold		Gross profit
Brazil	665,573	(460,284	)	205,289
Peru	1,159,264	(962,663	)	196,601
Holding	3	—		3
Total	1,824,840	(1,422,947	)	401,893

	Revised - 2015
	Net revenue from products sold	Cost of products sold		Gross profit
Brazil	665,573	(460,284	)	205,289
Peru	1,199,607	(1,003,006	)	196,601
Holding	3	—		3
Total	1,865,183	(1,463,290	)	401,893

2.2.2 Earnings per share (restated)

The restated information presented correct an error to the profit used in the numerator for the earnings per share calculation. The calculation was adjusted to use Profit (loss) attributable to owners of the parent in the numerator for the years ended December 31, 2016 and 2015, as required under IAS 33 – “Earnings per share”.

The restated information has no impact in the balance sheet, statement of comprehensive income, statement of changes in equity, net income and statements of cash flows.

The previously issued and revised calculation related to earnings per share are presented below:

	(Original)			(Restated)
	2016	Adjustment		2016
Earnings per share in US Dollars	1.37	(0.22	)	1.15

	(Original)			(Restated)
	2015		Adjustment	2015
Earnings per share in US Dollars	(74.60	)	5.52	(69.08	)

The presentation and disclosure of earnings per share attributable to owners of the parent is now presented in Income Statement as well as note 24 (f).

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Changes in accounting policies and disclosures

12 Months Ended

Dec. 31, 2017

Changes in accounting policies and disclosures

Changes in accounting policies and disclosures

3Changes in accounting policies and disclosures

(a)Change of applicable standards beginning on January 1, 2017

The International Accounting Standards Board (IASB) has published amendments to IAS 7, which intends to improve information provided to users of financial statements about Company’s financing activities. To check the required information, please refer to notes 5.2.

There were no more changes in standards adopted for the first time on January 1, 2017 which impact the Company and its subsidiaries.

(b)New standards and interpretations not yet adopted

IFRS 9 - “Financial instruments: Recognition and measurement”

Main aspects introduced by the standard

In July 2014, the IASB issued the final version of IFRS 9 — “Financial Instruments” which replaces IAS 39 and all previous versions of IFRS 9. IFRS 9 brings together all three aspects of the accounting for financial instruments project, which are classification and measurements, impairment, and hedge accounting. IFRS 9 is effective for annual periods beginning on or after January 1, 2018.

Impacts of adoption

The Company assessed the changes introduced by the standard and concluded that its adoption will not bring significant impacts, mainly regarding the measurement of the financial instruments when compared to the principles of the IAS 39. The main impacts are related to the financial asset’s classification. Once IFRS 9 has changed the categories for classification of the financial assets, eliminating the categories held-to-maturity, loans and receivables and available for sale, the financial assets will be classified in one of the following categories: at amortized cost, at fair value through other comprehensive income or, at fair value through profit or loss. Furthermore, some aspects regarding the presentation and the disclosure of the financial instruments in the financial statements might be changed in order to reflect the new concepts introduced by the IFRS 9.

IFRS 9 requires the utilization of an expected credit loss model for its trade receivables measured at amortized cost, either on a 12-month or lifetime basis. The Company will apply the simplified approach and record lifetime expected losses on all trade receivables measured at amortized cost. The Company expects these changes will not have a significant impact in the consolidated financial statements.

The changes introduced by the standard will not have significant impacts on how the Company accounts for hedge accounting transactions in its financial statements.

IFRS 15 — “Revenue from contracts with customers”

Main impacts introduced by the standard

IFRS 15 issued in May 2014, and amended in April 2016, establishes a single comprehensive model based on a five-step approach to account for revenue from contracts with customers. Under IFRS 15, revenue is recognized at an amount that reflects the consideration to which an entity expects to be entitled in exchange for transferring goods or services to a customer.

Impacts of adoption

The Company assessed the principles and changes introduced by the new standard and concluded that its adoption will not bring significant impacts on the timing and measurement for the revenue recognition from contracts with customers. Furthermore, some aspects regarding the presentation and the disclosure related to revenue recognition in the financial statements might be changed in order to reflect the new concepts introduced by IFRS 15.

IFRS 16 - “Leases”

Main impacts introduced by the standard

In January 2016, the IASB issued IFRS 16, which replaces IAS 17 — “Leases” and related interpretations. The IFRS 16 set forth that in all leases with a maturity of more than 12 months, with limited exceptions, the lessee must recognize the lease liability in the balance sheet at the present value of the payments, plus cost directly allocated and at the same time that it recognizes a right of use corresponding to the asset. During the term of the lease, the lease liability is adjusted to reflect interest and payment made and the right to use is amortized, similar to the financial lease settled up in accordance with IAS 17.

The standard is effective for accounting periods beginning on or after January 1, 2019 with early adoption permitted if IFRS 15 “Revenue from Contracts with Customers” has been adopted.

Impacts of adoption

The Company’s assessment of the impact of adoption of the standard is in progress. The assessment is being carried-out in order to identify the impacts mainly related to leases of offices, machinery and equipment, as well as other contracts that may be impacted by the standard.

There are no other IFRSs or IFRIC interpretations that are not yet effective that would be expected to have a material impact on the Company’s consolidated financial statements.

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Critical accounting estimates and judgments

12 Months Ended

Dec. 31, 2017

Critical accounting estimates and judgments

Critical accounting estimates and judgments

4Critical accounting estimates and judgments

Based on assumptions, NEXA and its subsidiaries makes estimates concerning the future. The resulting accounting estimates will, by definition, seldom equal the related actual results. The estimates and assumptions that have a significant risk of causing material adjustments to the carrying amounts of assets and liabilities within the next financial year are described in the respective note.

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Financial risk management

12 Months Ended

Dec. 31, 2017

Financial risk management

Financial risk management

5Financial risk management

5.1Financial risk factors

The Company’s activities expose it to a variety of financial risks: a) market risk (including currency risk, interest rate risk and commodities risk); b) credit risk; and c) liquidity risk.

A significant portion of the products sold by the Company are commodities, with prices pegged to international indexes and denominated in US Dollars. Part of the costs of production, however, is denominated in Brazilian Reais and Peruvian Soles, and therefore, there is a mismatch of currencies between revenue and costs. Additionally, the Company has debts linked to different indexes and currencies, which may impact its cash flow.

In order to mitigate the potential adverse effects of each financial risk factor, the Company adopted a Financial Risk Management Policy, that establish governance and guidelines for the financial risk management process, as well as metrics for measurement and monitoring. This policy establishes guidelines and rules for: (i) Commodities Exposure Management, (ii) Foreign Exchange Exposure Management, (iii) Interest Rate Exposure Management, (iv) Issuers and Counterparties Risk Management, and (v) Liquidity and Financial Indebtedness Management. All strategies and proposals must comply with the Financial Risk Management Policy guidelines and rules, be presented to and discussed with the Finance Committee, and, when applicable, submitted for the approval of the Board of Directors, under the governance structure described in the Financial Risk Management Policy.

(a)Market risk

The purpose of the market risk management process is to protect the Company’s cash flow against adverse events, such as fluctuations in exchange rates, commodity prices and interest rates.

(i)Foreign exchange risk

Foreign exchange risk is managed through using the Company’s Financial Risk Management Policy, which states that the objectives of derivative transactions are to reduce cash flow volatility, hedge against foreign exchange exposure and minimize currency mismatches.

The US Dollar is the Company’s functional currency, and all actions related to the market risk management process are intended to hedge cash flow in this currency, maintain the ability to pay financial obligations, and comply with liquidity and indebtedness levels defined by management.

Presented below are the financial assets and liabilities in foreign currencies at the end of the reporting year — these mainly result from the foreign operations of the subsidiary NEXA BR for which the functional currency is the Brazilian Real.

	2017	2016
Assets denominated in foreign currency
Cash, cash equivalents and financial investments	229,876	154,693
Derivative financial instruments	4,280	10,005
Trade accounts receivable	66,834	45,194
	300,990	209,892
Liabilities denominated in foreign currency
Loans and financing	161,706	95,124
Derivative financial instruments	3,634	—
Trade payables	78,286	61,075
	243,626	156,199
Net exposure	57,364	53,693

(ii)Cash flow and fair value risk associated with interest rates

The Company’s interest rate risk arises mainly from long-term loans. Loans at variable rates expose the Company to cash flow interest rate risk. Loans at fixed rates expose the Company to fair value risk associated with interest rates. For further information related to the interest rates, see note 16.

The Company’s Financial Risk Management Policy establishes guidelines and rules to hedge against fluctuations in interest rates that impact the cash flow of the Company and its subsidiaries.  Exposure to each interest rate is projected until the maturity of the assets and liabilities exposed to this index.

Occasionally the Company enters into floating to fixed interest rate swaps to manage its cash flow interest rate risk.

(iii)Commodity price risk

This risk is related to the volatility in the prices of the Company’s commodities. Prices fluctuate depending on demand, production capacity, producers’ inventory levels, the commercial strategies adopted by large producers, and the availability of substitutes for these products in the global market.

The Company’s Financial Risk Management Policy establishes guidelines to mitigate the risk of fluctuations in commodity prices that could impact the cash flow of the Company’s operating subsidiaries. The exposure to the price of each commodity considers the monthly projections of production, purchases of inputs and the maturity flows of hedges associated with them.

Hedge transactions are classified into the following categories:

(i.1)Fixed price commercial transactions (Customer Hedge) - hedging transaction that converts sales at fixed prices to floating prices in commercial transactions with customers interested in purchasing products at fixed prices. The purpose of this strategy is to maintain the revenue flow of the business unit with prices linked to the LME prices. These operations usually relate to purchases of zinc for future settlement on the over-the-counter market.

(i.2)Hedges for mismatches of “quotation periods” (Book Hedge) - hedges that set prices for the different “quotation periods” between the purchases of certain inputs (metal concentrate) and the sale of products arising from the processing of these inputs, or different “quotation periods” between the purchase and the sale of the same product. These operations usually relate to purchases and sales of zinc and silver for future trading on the over-the-counter market.

(i.3)Hedges for “operating margin” (Strategic Hedge) - derivatives contracted to reduce the volatility of the cash flow from its zinc, copper and silver operations. With a view to ensuring a fixed operating margin in Reais for a portion of the Brazilian production of metals, the mitigation of risks is carried out through the sale of zinc forward contracts with the sale of US Dollar forward contracts.

(b)Credit risk

Derivative financial instruments, term deposits, Bank Deposit Certificates (“CDB”) and repurchase transactions backed by debentures and government securities create exposure to credit risk with respect to the counterparties and issuers. The Company has a policy of making deposits in financial institutions that have, at least, a rating from two of the following international rating agencies: Fitch ratings, Moody’s or Standard & Poor’s. The minimum rating required for counterparties is A+ (local rating scale) or BBB- (global rating scale) (Note 7). In the specific case of financial institutions in Peru that only global rating assessments are available, it will be eligible provided it has rating “BBB-” at least by one rating agency.

The pre-settlement risk methodology is used to assess counterparty risks in derivative transactions. This methodology consists of determining the risk associated with the likelihood (via Monte Carlo simulations) of a counterparty not honoring the financial commitments defined by contract. The use of this methodology was approved by the Board of Directors.

The credit quality of financial assets is disclosed in Note 7. The ratings disclosed in this Note are always the most conservative ratings of the referred agencies.

In the case of credit risk arising from customer credit exposure, the Company assesses the credit quality of the customer, taking into account mainly the history of the relationship and financial indicators defining individual credit limits, which are continuously monitored. The Company recognizes a provision for uncollectible trade receivables whenever necessary.

The provision for uncollectible trade receivables is recorded at an amount sufficient to cover probable losses on the collection of trade accounts receivable and is charged to “Selling expenses”.

The Company performs initial analyses of customer credit and, when deemed necessary, guarantees or letters of credit are obtained to safeguard the Company’s interests. Additionally, most export sales to the United States, Europe and Asia are collateralized by letters of credit and credit insurance.

(c)Liquidity risk

This risk is managed through the Company’s Financial Risk Management Policy, which aims to ensure the availability of sufficient net funds to meet the Company’s financial commitments. The main liquidity measurement and monitoring instrument is the cash flow projection, using a minimum projection period of 12 months from the benchmark date.

The table below analyzes the Company’s non-derivative financial liabilities and derivative financial assets and liabilities to be settled by the Company based on their maturity (the remaining period from the balance sheet up to the contractual maturity date). Derivative financial liabilities are included in the analysis if their contractual maturities are essential to understand the timing of cash flow.

The amounts disclosed in the table represent the estimated future cash flow, which include interest to be incurred and, accordingly, do not reconcile directly with the amounts recorded in the balance sheet for loans and financing, related parties and use of public assets.

	Less than 1 year	Between 1 and 3 years	Between 3 and 5 years	Over 5 years	Total
At December 31, 2017
Loans and financing	102,294	373,324	236,927	1,228,474	1,941,018
Derivative financial instruments	12,588	2,449	—	—	15,037
Trade payables	329,814	—	—	—	329,814
Confirming payable	111,024	—	—	—	111,024
Salaries and payroll charges	79,798	—	—	—	79,798
Dividends payable	4,138	—	—	—	4,138
Related parties	87,686	2,238	—	—	89,924
Provisions - Asset Retirement Obligation	7,526	53,429	33,186	237,788	331,929
Use of public assets	1,740	3,755	4,233	45,309	55,037
	736,607	435,195	274,346	1,511,571	2,957,719
At December 31, 2016
Loans and financing	104,191	438,569	432,587	375,480	1,350,827
Derivative financial instruments	37,458	—	—	—	37,458
Trade payables	282,241	—	—	—	282,241
Confirming payable	102,287	—	—	—	102,287
Salaries and payroll charges	70,022	—	—	—	70,022
Dividends payable	7,185	—	—	—	7,185
Related parties	222,917	7,596	—	—	230,513
Provisions - Asset Retirement Obligation	33,143	25,296	35,813	123,827	218,079
Use of public assets	1,754	3,832	4,319	51,449	61,354
	861,198	475,293	472,719	550,756	2,359,966

5.2Capital management

The Company’s objectives when managing its capital structure are to ensure that the Company can consistently provide returns for shareholders and benefits for other stakeholders and to reduce the cost of capital by maintaining an optimal capital structure.

In order to maintain or adjust the capital structure of the Company, management can make, or may propose to the Board of Directors or to the shareholders when their approval is required, adjustments to the amounts of dividends paid to shareholders, return capital to shareholders, issue new shares or sell assets to reduce debt, for example.

One of the important indicators through which the Company monitors its capital is the gearing ratio, calculated as net debt divided by Adjusted EBITDA.

Net debt is defined as (i) loans and financing, less (ii) cash and cash equivalents, less (iii) financial investments, plus or less (iv) the fair value of derivative financial instruments.

The Adjusted EBITDA is defined as (i) profit (loss) for the year, plus (ii) profit (loss) from results of associates, plus (iii) depreciation and amortization, plus/less (iv) net financial results, plus/less (v) tax on income, less (vi) gain on sale of investment (loss), plus (vii) impairment of other assets, plus/less (viii) (reversion) impairment of property, plants and equipment. In addition, management may exclude non cash and non-recurring items considered exceptional from the measurement of Adjusted EBITDA.

Net debt and Adjusted EBITDA measures should not be considered in isolation or as a substitute for profit (loss) or operating profit, as indicators of operating performance, or as alternatives to cash flow as measures of liquidity. Additionally, the management calculation of Adjusted EBITDA may be different from the calculation used by other companies, including competitors in the mining and smelting industry, so these measures may not be comparable to those of other companies.

The net debt ratio is as follows:

	Note	2017		2016		2015
Loans and financing	16	1,447,299		1,144,385		1,056,210
Cash and cash equivalents	8	(1,019,037	)	(915,576	)	(621,415	)
Derivative financial instruments	5.4	3,260		16,718		(10,105	)
Financial investments	9	(206,547	)	(119,498	)	(57,856	)
Net debt (A)		224,975		126,029		366,834
Profit for the year		165,265		110,509		(139,796	)
Plus (less):
Results of investees		(60	)	158		256
Results of investees - Discontinued operations		—		—		318
Depreciation and amortization	14 and 15	270,454		275,034		295,258
Net financial results	29	130,181		(79,081	)	341,931
Taxes on income	20(a)	106,194		98,383		(38,779	)
EBITDA		672,034		405,003		459,188
Exceptional items
Gains on sales of investments	28	(4,588	)	(408	)	—
Impairment of other assets		73		308		—
(Reversal) Impairment - property, plant, equipment	28	—		(979	)	8,574
Adjusted EBITDA (B)		667,519		403,924		467,762
Gearing ratio (A/B)		0.34		0.31		0.78

The net debt reconciliation is as follows:

	Cash and cash equivalents		Financial investments		Derivative financial instruments		Loans and financing		Net debt
Net debt as at 1 January 2017	(915,576	)	(119,498	)	16,718		1,144,385		126,029
Cash flows	(103,413	)	(65,661	)	39,006		236,306		106,238
Foreign exchange ajustments	(48	)	—		—		(2,873	)	(2,921	)
Other non-cash movements	—		(21,388	)	(52,464	)	69,481		(4,371	)
Net debt as at 31 December 2017	(1,019,037	)	(206,547	)	3,260		1,447,299		224,975

5.3Fair value estimates

Critical accounting estimates and judgments

The fair values of financial instruments that are not traded in an active market is determined using valuation techniques. The Company uses judgment to select among a variety of methods and makes assumptions that are mainly based on market conditions existing at the end of each reporting period.

(a)Analysis

The carrying amounts of trade accounts receivable, less a provision for uncollectible trade receivables, and of trade accounts payable, confirming payables and advances from customers approximate their fair values. The fair value of financial liabilities for disclosure purposes are estimated by discounting the future contractual cash flow at the current market interest rate.

The main financial instruments and the assumptions made by the Company for their valuation are described below:

· Cash and cash equivalents, financial investments, trade accounts receivable and other current assets - considering their nature and terms, the carrying amounts approximate their realizable values, due to their short-term duration.

· Financial liabilities - these instruments are subject to the usual market interest rates. The market value was based on the present value of expected future cash disbursement, at interest rates currently available for debt with similar maturities and terms.

· Derivative financial instruments — the fair value of the derivative instruments used by the Company for hedging transactions are evaluated by calculating their present value through yield curves at the closing dates. The curves and prices used in the calculation for each group of instruments are developed based on data from B3 (formerly BM&FBOVESPA), Central Bank of Brazil, London Metals Exchange and Bloomberg. When there is no price for the desired maturity, NEXA uses an interpolation between the available maturities.

· Swap contracts - the present value of both the assets and liabilities are calculated through the discount of forecasted cash flow by the interest rate of the currency in which the swap is denominated. The difference between the present value of the assets and the liabilities generates its fair value.

· Forward contracts — the present value is estimated discounting the notional amount multiplied by the difference between the future price in the reference date and contracted price. The future price is calculated using the convenience yield of the underlying asset. It is common to use Asian Non-deliverable Forwards for hedging Non-Ferrous Metals positions. Asian contracts are derivatives which the underlying is the average price of certain asset over a range of days.

Fair value hierarchy

The Company discloses fair value measurements based on their level of the following fair value measurement hierarchy:

· Quoted prices (unadjusted) in active markets for identical assets and liabilities (Level 1).

· Inputs other than quoted prices included within Level 1 that are observable for the asset or liability, either directly (that is, as prices) or indirectly (that is, derived from prices) (Level 2).

· Inputs for the asset or liability that are not based on observable market data (that is, unobservable inputs) (Level 3). In December 31, 2017, there were not any financial assets and liabilities carried at fair value classified as Level 3.

At December 31, the financial assets and liabilities carried at fair value were classified as Level 1 and 2 in the fair value measurement hierarchy, see classification as follows:

		2017
		Fair value measured based on
		Price quoted in an active market	Valuation technique supported by observable prices
	Note	Level 1	Level 2	Total fair value
Assets
Cash and cash equivalents	8	1,019,037	—	1,019,037
Financial investments	9	134,168	72,379	206,547
Derivative financial instruments	5.4	—	11,777	11,777
		1,153,205	84,156	1,237,361
Liabilities
Loans and financing	16(a)	1,120,901	414,231	1,535,132
Derivative financial instruments	5.4	—	15,037	15,037
		1,120,901	429,268	1,550,169

		2016
		Fair value measured based on
		Price quoted in an active market	Valuation technique supported by observable prices
	Note	Level 1	Level 2	Total fair value
Assets
Cash and cash equivalents	8	915,576	—	915,576
Financial investments	9	65,964	53,534	119,498
Derivative financial instruments	5.4	—	20,740	20,740
		981,540	74,274	1,055,814
Liabilities
Loans and financing	16(a)	342,156	808,729	1,150,885
Derivative financial instruments	5.4	—	37,458	37,458
		342,156	846,187	1,188,343

(i)Financial instruments - Level 1

The fair value of financial instruments traded in active markets (such as trading securities and available-for-sale securities) are based on quoted market prices at the balance sheet date. A market is regarded as active if quoted prices are readily and regularly available from an exchange, dealer, broker, industry group, pricing service, or regulatory agency, and those prices represent actual and regularly occurring market transactions on an arm’s length basis. The quoted market price used for financial assets held by the Company is the current bid price. These instruments are included in Level 1. Instruments included in Level 1 primarily include investments in federal government securities classified as trading securities or available-for-sale securities.

(ii)Financial instruments - Level 2

The fair value of financial instruments not traded in an active market (for example, over-the-counter derivatives) are determined using valuation techniques. These valuation techniques maximize the use of observable market data where it is available and rely as little as possible on entity-specific estimates. If all of the significant inputs required to identify the fair value of an instrument are observable, the instrument is included in Level 2.

Specific valuation techniques used to value financial instruments include:

· Quoted market prices or dealer quotes for similar instruments are used where available;

· The fair values of interest rate swaps are calculated at the present value of the estimated future cash flow based on observable yield curves;

· The fair value of forward foreign exchange contracts is determined using forward exchange rates at the balance sheet date, with the resulting value discounted to present value;

· Other techniques, such as discounted cash flow analysis, are used to determine the fair value for the remaining financial instruments.

There were no transfers between Levels 1 and 2 during the year. There is no financial items valued using level 3.

5.4Derivatives

Accounting policy

Derivatives are initially recognized at fair value as at the date on which a derivative contract is entered into and are subsequently measured again at fair value. The method of recognizing the resulting gain or loss depends on whether the derivative is designated as a hedging instrument, in the case of adoption of hedge accounting, and if so, the nature of the item being hedged. The Company adopts the hedge accounting procedure and designates certain derivatives as either:

Hedges of the fair value of recognized assets or liabilities or a firm commitment (fair value hedge); or

Hedges of a particular risk associated with a recognized asset or liability or a highly probable forecast transaction (cash flow hedge).

The Company documents at the inception of the hedging transaction the relationship between hedging instruments and hedged items, as well as its risk management objectives and strategy for undertaking various hedge transactions. The Company also documents its assessment, both at hedge inception and on an ongoing basis, of whether the derivatives that are used in hedging transactions have been, and will continue to be, highly effective in offsetting changes in the fair value or cash flow of hedged items.

The full fair value of a hedging derivative is classified as a non-current asset or liability when the remaining maturity of the hedged item is more than 12 months, and as a current asset or liability when the remaining maturity of the hedged item is less than 12 months.

(i)Cash flow hedge

To ensure a fixed operating margin for a part of its production, the Company contracts derivative financial instruments for the forward sale of each commodity (zinc, copper and silver), and for NEXA BR, which has Reais as its functional currency, derivative financial instruments also includes the forward sale of US Dollars. The Company adopts hedge accounting for derivative instruments contracted for hedging purposes. The effective portion of the changes in fair value of derivatives that are designated and qualify as cash flow hedges is recognized in equity, recorded in “Accumulated other comprehensive income (loss)”. Gains and losses related to the non-effective portion are immediately recognized as “Other operating expenses, net”. The amounts recognized in equity are taken to the income statement upon realization of the hedged exports and/or sales referenced to the LME price.

Amounts accumulated in shareholders’ equity are reclassified to profit or loss in the periods when the hedged item affects the profit or loss (for example, when the forecast sale that is being hedged takes place).  The gain or loss relating to the effective portion of interest rate swaps hedging variable rate borrowing is recognized in the income statement within “Net financial results”.

When a hedging instrument expires or is sold, or when a hedge no longer meets the criteria for hedge accounting, any cumulative gain or loss existing in equity at that time remains in equity and is recognized when the forecast transaction is ultimately recognized in the income statement. When a forecast transaction is no longer expected to occur, the cumulative gain or loss that was reported in equity is immediately transferred to the income statement within “Other operating expenses, net”.

(ii)Fair value hedge

The Company has entered into commodities prices forwards that are fair value hedges for LME fluctuation risk arising from its firm commitments for purchases and sales of such commodities. The Company adopts hedge accounting for derivative instruments contracted for hedging purposes. Changes in the fair values of derivatives that are designated and qualify as fair value hedges are recorded in “Other operating expenses, net”. The change in the fair value of the hedged item is also recorded in “Other operating expenses, net”.

(iii)Derivatives carried at fair value through profit or loss

Certain derivative instruments do not qualify for hedge accounting. Changes in the fair values of any of these derivative instruments are recognized immediately in the income statement within “Other operating expenses, net”. Instruments not qualifying as hedges that are intended to hedge fluctuations in interest rates are classified in “Net financial results”.

(a)Analysis

All derivative transactions were carried out on the over-the-counter market and the Company has the following hedge programs in place:

· Hedging program for sales of zinc at a fixed price (Customer Hedge) - hedging transaction that converts sales at fixed prices to floating prices in commercial transactions with customers interested in purchasing products at fixed prices. The purpose of this strategy is to maintain the revenue flow of the business unit with prices linked to the LME prices. These operations usually relate to purchases of zinc for future settlement on the over-the-counter market.

· Hedging program for mismatches of quotation periods (Book Hedge) - this program hedges the different “quotation periods” between the purchases of certain inputs (metal concentrate) and sales of products arising from the processing of these inputs, or different “quotation periods” between the purchase and the sale of the same product. These operations usually relate to purchases and sales of zinc and silver for future trading on the over-the-counter market.

· Hedging program for the operating margins of metals (Strategic Hedge) - derivatives contracted to reduce the volatility of the cash flow from its zinc, copper and silver operations. With a view to ensuring a fixed operating margin in Reais for a portion of the Brazilian production of metals, the mitigation of risks is carried out through the sale of zinc forward contracts, with the sale of US Dollar forward contracts.

The table below summarizes the derivative financial instruments and the underlying hedged items as at 31 December:

	Principal			Average terms	Fair value				Realized gain (loss)		Fair value by maturity
Program	2017	2016	per unit	(days)	2017		2016		2017		2018		2019		2020
Hedging instrument for sales of zinc at a fixed price
Zinc forward	2,230	615	ton	127	603		369		1,288		589		14		—
					603		369		1,288		589		14		—
Hedging instrument for mismatches of quotation periods
Zinc forward	240,747	146,515	ton	23	(4,304	)	4,471		(2,183	)	(4,304	)	—		—
Silver forward	238	—	k oz	17	196		—		(24	)	196		—		—
					(4,108	)	4,471		(2,207	)	(4,108	)	—		—
Hedging instrument for the operating margin of metals
Zinc forward	—	10,790	—	—	—		(7,110	)	—		—		—		—
US Dollar forward	—	8,039	—	—	—		1,784		—		—		—		—
					—		(5,326	)	—		—		—		—
Hedging instrument for interest rates in US Dollar
LIBOR floating rate vs. US Dollar fixed rate swaps	31,393	—	USD	849	646		—		(1,200	)	(1,186	)	(1,543	)	3,375
					646		—		(1,200	)	(1,186	)	(1,543	)	3,375
Total (assets and liabilities, net)					(2,859	)	(486	)	(2,119	)	(4,705	)	(1,529	)	3,375

The table below presents a summary of hedge accounting derivatives operations and their fair values:

	Principal			Average terms	Fair value				Realized gain (loss)		Fair value by maturity
Program	2017	2016	per unit	(days)	2017		2016		2017		2018
Hedging instruments for mismatches of quotation periods - Fair value
Zinc forward	87,693	22,390	ton	43	(3,319	)	32		(12,310	)	(3,319	)
					(3,319	)	32		(12,310	)	(3,319	)
Hedging instruments for mismatches of quotation periods - Cash flow
Zinc forward	58,800	43,294	ton	47	2,986		(1,728	)	4,450		2,986
Silver forward	265	—	k oz	58	(68	)	—		(94	)	(68	)
					2,918		(1,728	)	4,356		2,918
Hedge accounting - Cash flow hedge
Zinc forward	—	94,559	—	—	—		(22,967	)	(43,898	)	—
Copper forward	—	540	—	—	—		210		(171	)	—
US Dollar forward	—	93,467	—	—	—		8,221		15,134		—
					—		(14,536	)	(28,935	)	—
					(401	)	(16,232	)	(36,889	)	(401	)
Current assets					7,483		20,740
Non-current assets					4,294		—
Current liabilities					(12,588	)	(37,458	)
Non-current liabilities					(2,449	)	—
					(3,260	)	(16,718	)

5.5Sensitivity analysis

Presented below is a sensitivity analysis of the main risk factors that affect the pricing of the outstanding financial instruments relating to cash and cash equivalents, financial investments, loans and financing, and derivative financial instruments. The main sensitivities are the exposure to the fluctuations of the US Dollar exchange rate, the London Interbank Offered Rate (LIBOR) and Interbank Deposit Certificate (CDI) interest rates, the US Dollar coupon and the commodity prices. The scenarios for these factors are prepared using market sources and other relevant sources, in compliance with the Company’s policies.

The scenarios at December 31, 2017 are described below:

· Scenario I: considers a change in the market forward yield curves and quotations as of December 31, 2017, according to the base scenario defined by the Company for March 31, 2018.

· Scenario II: considers a change of + or -25% in the market forward yield curves as of December 31, 2017.

· Scenario III: considers a change of + or -50% in the market forward yield curves as of December 31, 2017.

					Impacts on profit (loss)												Impacts on comprehensive income
					Scenario I				Scenarios II e III								Scenario I		Scenarios II e III
Risk factor	Cash and cash equivalents and financial investments	Loans and financing	Principal of derivative financial instruments	Unit	Changes from 2017		Results of scenario I		-25%		-50%		+25%		+50%		Results of scenario I		-25%		-50%		+25%		+50%
Exchange variation rate
USD	11,339	40,274	31,393	USD	-3.81	%	(153	)	(3,328	)	(17,218	)	(897	)	(3,906	)	—		—		—		—		—
BRL	203,392	161,706	—	—	3.97	%	—		—		—		—		—		6,127		53,441		156,447		(28,963	)	(49,564	)
EUR	1,692	—	—	EUR	-1.66	%	(28	)	(423	)	(846	)	423		846		—		—		—		—		—
PEN	22,830	—	—	PEN	0.68	%	155		(5,707	)	(11,415	)	5,707		11,415		—		—		—		—		—
Interest rates
BRL - CDI	202,311	70,720	103,849	BRL	0 bps		—		(2,029	)	(4,044	)	2,043		4,098
USD - LIBOR	—	130,610	1,282,900	USD	-2 bps		14		217		435		(217	)	(435	)	(0	)	(6	)	(12	)	6		12
US Dollar coupon	—	—	31,393	USD	3 bps		(21	)	515		1,047		(499	)	(981	)	—		—		—		—		—
Price - commodities
Zinc	—	—	389,470	ton	-2.90	%	13,073		51,744		103,488		(51,744	)	(103,488	)	(580	)	(2,297	)	(4,594	)	2,297		4,594
Silver	—	—	503	k oz	5.20	%	(9	)	281		562		(281	)	(562	)	(36	)	1,124		2,248		(1,124	)	(2,248	)

The figures presented in USD refer to derivatives whose functional currency is different from the U.S. Dollar.

5.6Value and type of margins pledged in guarantee

The derivative transactions entered into by the Company are not subject to collateral deposits, margin calls or any other type of guarantee or similar mechanism.

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Financial instruments by category

12 Months Ended

Dec. 31, 2017

Financial instruments by category

Financial instruments by category

6Financial instruments by category

Accounting policy

Normal purchases and sales of financial assets are recognized on the trade date — the date on which the Company commits to purchase or sell the asset. Investments are initially recognized at fair value plus transaction costs for all financial assets not carried at fair value through profit or loss. Financial assets carried at fair value through profit or loss, if any, are initially recognized at fair value, and transaction costs are expensed in the income statement.

Financial assets are derecognized when the rights to receive cash flow from the investments have expired or the Company has transferred substantially all of the risks and rewards of ownership. Financial assets at fair value through profit or loss are subsequently carried at fair value. Loans and receivables are carried at amortized cost using the effective interest rate method.

Gains or losses arising from changes in the fair value of the financial assets held for trading are presented in the income statement under “Net financial results” in the year in which they arise.

The fair values of quoted investments are based on current market prices.  If the market for a financial asset is not active, the Company establishes the fair value using valuation techniques. These include the use of recent arm’s length transactions, reference to other instruments that are substantially the same, discounted cash flow analysis, and option pricing models making maximum use of market inputs and relying as little as possible on entity-specific inputs.

The Company and its subsidiaries classify their financial assets under the following categories: at fair value through profit or loss (held for trading), held to maturity and loans and receivables. The classification depends on the purpose for which the financial assets were acquired. Management determines the classification of its financial assets upon initial recognition.

(i)Financial assets at fair value through profit or loss

Financial assets at fair value through profit or loss are financial assets held for trading. A financial asset is classified in this category if it was acquired principally for the purpose of selling in the short term. The changes are recognized in the income statement for the year within “Net financial results”. All financial assets in this category are classified as current assets.

Derivatives are also categorized as held for trading, unless they are designated as hedges.

(ii)Held to maturity

Investments in non-derivative marketable securities made by the Company with the ability and intention of being held to maturity, are classified as held to maturity investments and recorded at amortized cost. The Company assesses, at the balance sheet date, whether there is objective evidence that a financial asset or group of financial assets is impaired. If such evidence exists, a provision for the impairment of the asset is recorded.

(iii)Loans and receivables

Loans and receivables are non-derivative financial assets with fixed or determinable payments that are not quoted in an active market.  They are included in current assets, except for those with maturities greater than 12 months after the end of the reporting period, which are classified as non-current assets. The Company’s loans and receivables are mainly comprised of “cash and cash equivalents” and “trade accounts receivable”.

(a)Analysis

		2017
Assets per balance sheet	Note	Loans and receivables	Assets held for trading	Held-to- maturity investments	Derivatives used for hedging	Total
Cash and cash equivalents	8	1,019,037	—	—	—	1,019,037
Financial investments	9	—	206,547	—	—	206,547
Derivative financial instruments	5.4	—	8,811	—	2,966	11,777
Trade accounts receivable	10	182,713	—	—	—	182,713
Related parties	13	738	—	—	—	738
		1,202,488	215,358	—	2,966	1,420,812

		2017
Liabilities per balance sheet	Note	Liabilities at fair value through profit or loss	Derivatives used for hedging	Other financial liabilities	Total
Loans and financing	16	—	—	1,447,299	1,447,299
Derivative financial instruments	5.4	12,842	2,195	—	15,037
Trade payables		—	—	329,814	329,814
Confirming payable	17	—	—	111,024	111,024
Use of public assets	22	—	—	24,309	24,309
Related parties	13	—	—	89,924	89,924
		12,842	2,195	2,002,370	2,017,407

		2016
Assets per balance sheet	Note	Loans and receivables	Assets held for trading	Held-to- maturity investments	Derivatives used for hedging	Total
Cash and cash equivalents	8	915,576	—	—	—	915,576
Financial investments	9	—	119,498	—	—	119,498
Derivative financial instruments	5.4	—	6,649	—	14,091	20,740
Trade accounts receivable	10	120,062	—	—	—	120,062
Related parties	13	400,798	—	—	—	400,798
		1,436,436	126,147	—	14,091	1,576,674

		2016
Liabilities per balance sheet	Note	Liabilities at fair value through profit or loss	Derivatives used for hedging	Other financial liabilities	Total
Loans and financing	16	—	—	1,144,385	1,144,385
Derivative financial instruments	5.4	2,564	34,894	—	37,458
Trade payables		—	—	282,241	282,241
Confirming payable	17	—	—	102,287	102,287
Use of public assets	22	—	—	25,920	25,920
Related parties	13	—	—	230,513	230,513
		2,564	34,894	1,785,346	1,822,804

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Credit quality of financial assets

12 Months Ended

Dec. 31, 2017

Credit quality of financial assets

Credit quality of financial assets

7Credit quality of financial assets

The following table reflects the credit quality of issuers and counterparties for transactions involving cash and cash equivalents, financial investments and derivative financial instruments:

	2017			2016
	Local rating	Global rating	Total	Local rating	Global rating	Total
Cash and cash equivalents
AA+	1,089	—	1,089	5,917	—	5,917
AA-	—	115,269	115,269	13,699	250,038	263,737
A+	—	172,052	172,052	4,919	109,544	114,463
A	—	235,445	235,445	—	65,398	65,398
A-	3	86,189	86,192	15,515	94,454	109,969
BBB+	—	96,436	96,436	75,952	20	75,972
BBB	—	110,733	110,733	121,111	209	121,320
BB	—	—	—	2,239	—	2,239
No rating	—	201,821	201,821	80,365	76,196	156,561
	1,092	1,017,945	1,019,037	319,717	595,859	915,576
Financial investments
AA+	17,111	—	17,111	—	—	—
AA-	180,127	4,238	184,365	113,732	—	113,732
A-	5,053	—	5,053	—	3,225	3,225
No rating	—	18	18	—	2,541	2,541
	202,291	4,256	206,547	113,732	5,766	119,498
Derivative financial instruments
AA-	4,769	3,634	8,403	5,511	—	5,511
A+	—	3,141	3,141	1,587	80	1,667
A	—	233	233	—	4,826	4,826
A-	—	—	—	—	8,736	8,736
	4,769	7,008	11,777	7,098	13,642	20,740
	208,152	1,029,209	1,237,361	440,547	615,267	1,055,814

The global ratings were obtained from the rating agencies Standard & Poor’s, Moody’s and Fitch ratings.

Global rating: Global ratings are related to commitments in foreign or local currency and, in both cases, they assess the capacity to honor these commitments, using a scale applicable on a global basis. Therefore, both ratings in foreign currency and in local currency are internationally comparable ratings.

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Cash and cash equivalents

12 Months Ended

Dec. 31, 2017

Cash and cash equivalents

Cash and cash equivalents

8Cash and cash equivalents

Accounting policy

Cash and cash equivalents includes cash, bank deposits, and highly liquid short-term investments (investments with an original maturity less than 90 days), which are readily convertible into a known amount of cash and subject to an immaterial risk of changes in value and bank overdrafts. Bank overdrafts are shown within loans and financing in current liabilities in the balance sheet.

(a)Composition

	2017	2016
Cash and banks	319,920	338,054
Term deposits	699,117	577,522
	1,019,037	915,576

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Financial investments

12 Months Ended

Dec. 31, 2017

Financial investments

Financial investments

9Financial investments

Held for trading	2017	2016
Investment fund quotas (i)	138,945	95,504
Bank Deposit Certificate	42,067	15,042
Repurchase agreements	18,289	—
Credit Rights Investment Funds	5,053	4,682
Financial Treasury Bills	1,123	4,270
Other	1,070	—
	206,547	119,498

Investments in Brazil represent government and financial institution bonds, indexed to the interbank deposit rate.

(i)The shares held in the investment fund relate to a fund that is exclusively held by VSA and its subsidiaries and NEXA’s stake in this fund is 11% (2016: 8%). The composition of the investment fund’s portfolio is as follows (pro rata to the Company’s stake):

	2017	2016
Repurchase agreements - Public securities	131,999	60,803
Repurchase agreements	5,900	20,797
Bank Deposit Certificate	—	13,009
Financial Treasury Bills	1,046	891
Credit Right Investment Funds	—	4
	138,945	95,504

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Trade accounts receivable

12 Months Ended

Dec. 31, 2017

Trade accounts receivable.

Trade accounts receivable

10Trade accounts receivable

Accounting policy

Trade accounts receivable are amounts due from customers for goods sold in the ordinary course of the Company’s business.

Trade accounts receivable are recognized initially at fair value and subsequently measured at amortized cost using the effective interest rate method, less a provision for uncollectible trade receivables. Trade accounts receivable from export sales are presented at the foreign exchange rates prevailing on the reporting date.

Credit risk can arise from non-performance by counterparties of their contractual obligations towards the Company. To ensure an effective evaluation of credit risk, management applies comprehensive procedures related to the application for credit granting and approvals, renewal of credit limits, continuous monitoring of credit exposure in relation to established limits and events that trigger requirements for secured payment terms. As part of the Company’s process, the credit exposures with all counterparties are regularly monitored and assessed on a timely basis.

The Company recognized provision for uncollectible trade receivables for notes overdue for more than 120 days, whose expectation of collection is unlikely, as well as for customers considered bankrupt or in judicial reorganization.

(a)Composition

	Note	2017		2016
Trade receivables		181,084		115,291
Related parties	13	3,775		6,389
Provision for uncollectible trade receivables		(2,146	)	(1,618	)
		182,713		120,062

(b)Changes in the provision for uncollectible trade receivables

	2017		2016
Balance at the beginning of the year	(1,618	)	(2,047	)
Reversals (additions), net	(521	)	653
Exchange variation losses	(7	)	(224	)
Balance at the end of the year	(2,146	)	(1,618	)

The additions to the provision for uncollectible trade receivables have been included in “selling expenses”. Amounts charged to the provision for uncollectible trade receivables are generally written off when there is no expectation of recovering additional cash.

(c)Analysis by currency

	2017	2016
Brazilian Real	66,486	44,924
US Dollar	115,879	74,868
Other	348	270
	182,713	120,062

(d)Aging of accounts receivable

	2017		2016
To fall due	163,196		113,155
Up to 3 months	19,775		6,054
From 3 to 6 months	914		1,169
Over 6 months	974		1,302
	184,859		121,680
Provision for uncollectible trade receivables	(2,146	)	(1,618	)
	182,713		120,062

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Inventory

12 Months Ended

Dec. 31, 2017

Inventory.

Inventory

11Inventory

Accounting policy

Inventory is stated at the lower of cost and net realizable value. Cost is determined using the weighted average cost method. The cost of finished goods and work in progress comprises raw materials, direct labor, other direct costs and related production overheads (based on normal operating capacity). The net realizable value is the estimated selling price in the ordinary course of business, less any additional selling expenses.  Imports in transit are stated at the accumulated cost of each import.

The Company, at least once a year, counts its physical inventory of goods to ensure that the physical balances and the recorded balances are the same. Any adjustment to be performed is booked under “Cost of products sold”.

(a)Composition

	2017		2016
Finished products	106,026		121,969
Semi-finished products	85,458		65,054
Raw materials	30,128		17,511
Auxiliary materials and consumables	81,261		104,972
Imports in transit	41,878		20,631
Other	863		15
Provision for obsolete and slow-moving inventory	(20,736	)	(38,384	)
	324,878		291,768

The Company had no inventory pledged as collateral for any of its liabilities.

(b)Changes in the provision for obsolete and slow-moving inventory

	2017										2016
	Finished products		Semi- finished products		Raw materials		Auxiliary materials and consumables		Total		Total
Balance at the beginning of the year	(768	)	(10,167	)	(153	)	(27,296	)	(38,384	)	(36,985	)
Reversals (additions), net	727		(2	)	(63	)	16,773		17,435		3,090
Exchange variation gains (losses)	1		150		2		60		213		(4,489	)
Balance at the end of the year	(40	)	(10,019	)	(214	)	(10,463	)	(20,736	)	(38,384	)

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Taxes recoverable

12 Months Ended

Dec. 31, 2017

Taxes Recoverable.

Taxes recoverable

12Taxes recoverable

	2017	2016
Value-added Tax on Sales and Services	50,616	64,428
Corporate taxes on Net Income	25,165	34,130
Social Contribution on Revenue	18,824	16,831
Social Integration Program	4,302	3,959
Other	13,737	10,384
	112,644	129,732
Current	80,134	102,996
Non-current	32,510	26,736
	112,644	129,732

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Related parties

12 Months Ended

Dec. 31, 2017

Related parties.

Related parties

13Related parties

	Trade accounts receivable		Non-current assets		Trade payables		Dividends payable		Current and non-current liabilities
	2017	2016	2017	2016	2017	2016	2017	2016	2017	2016
Parent
Votorantim S.A. (i)	8	75	3	3	336	257	—	—	87,686	52,873
Related parties
Companhia Brasileira de Alumínio (ii)	1,843	3,847	—	399,725	5,246	9,064	—	2,423	13	5,614
Votorantim Cimentos S.A.	1,696	1,891	735	750	47	24	—	—	—	—
Other	228	576	—	320	1,414	680	655	—	2,225	1,956
Non-controlling interests (iii)	—	—	—	—		—	3,483	4,762	—	170,070
	3,775	6,389	738	400,798	7,043	10,025	4,138	7,185	89,924	230,513
Current	3,775	6,389		—	7,043	10,025	4,138	7,185	87,686	222,917
Non-current		—	738	400,798		—	—	—	2,238	7,596
	3,775	6,389	738	400,798	7,043	10,025	4,138	7,185	89,924	230,513

(i) The compensation to VSA of an amount equivalent to the economic benefits derived from the Energy Assets was calculated based on the difference between a predetermined comparable market rate and the cost of producing the energy consumed by the Brazilian subsidiaries, resulting in an additional liability of US$24,928 for the period January to June 2017 (and US$ 52,873 in 2016). In addition, an accrual of US$ 62,733 was recorded, due to the right to retain the Energy Assets, as described in note 1 (vii), and the Energy Assets compensation related to December 2016 was paid, as described in note 1 (iii);

(ii) CBA liquidated the amount related to the transaction mentioned in note 1 (i);

(iii) The responsibility of the put option that had been granted by the Company to the minority shareholders amounting US$ 170,070 was transferred to VSA, as per note 1 (vi). After the IPO, the obligation expired as part of the termination of the shareholders’ agreement.

	Sales			Purchases			Financial results
	2017	(Revised) 2016	(Revised) 2015	2017	(Revised) 2016	(Revised) 2015	2017	(Revised) 2016	(Revised) 2015
Related parties
Companhia Brasileira de Alumínio	2,125	70	23	42,434	31,162	3,924	1,012	3,582	—
Votoratim Metais S.A. (i)	—	—	—	—	51	29	—	3,583	5,702
Votener - Votorantim Comercializadora de Energia Ltda.	—	—	12,436	13,510	13,400	28,869	—	—	—
Votorantim Cimentos S.A.	138	45	73	365	273	338	—	—	—
Other	—	2,856	1,265	1,134	1,427	9,755	—	—	—
	2,263	2,971	13,797	57,443	46,313	42,915	1,012	7,165	5,702

(i) Votorantim Metais S.A. was merged into CBA in July 2016.

(a)Key management compensation

Key management includes the members of the Company’s global executive team and Board of Directors. Key management compensation, including all benefits, was as follows:

	2017	2016	2015
Short-term benefits to managers	6,668	7,310	4,945
Other long-term benefits to key management	1,162	1,686	836
	7,830	8,996	5,781

The short-term benefits above include fixed compensation (salaries and fees, paid vacations and 13th month salary), social charges (contribution to the Social Security system and severance indemnity fund) and short-term benefits under the Company’s variable compensation program. The other long-term benefits relate to the variable compensation program.

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Property, plant and equipment

12 Months Ended

Dec. 31, 2017

Property, plant and equipment

Property, plant and equipment

14Property, plant and equipment

Accounting policy

Property, plant and equipment are stated at the historical cost of acquisition or construction less accumulated depreciation. Historical cost includes expenditure that is directly attributable to the acquisition and construction of the qualifying assets.

Subsequent costs are included in the asset’s carrying amount, or recognized as a separate asset as appropriate, only when it is probable that future economic benefits associated with the item will flow to the Company and they can be measured reliably. The carrying amounts of the replaced items or parts are derecognized.

All other repairs and maintenance are charged to the income statement during the financial period in which they are incurred. The cost of major renovations is included in the carrying amount of the asset when it is probable that the Company will realize future economic benefits in excess of the original benchmark performance specifications of the existing asset. Renovations are depreciated over the remaining useful life of the related asset.

Land is not depreciated. Depreciation of other assets is calculated using the straight line method to reduce their costs to their residual values over their estimated useful lives.

The assets’ residual values and useful lives are reviewed, and adjusted if appropriate, at the end of each reporting period.

An asset’s carrying amount is written down immediately to the recoverable amount when it is greater than the estimated recoverable amount, in accordance with the criteria adopted by the Company in order to determine the recoverable amount.

Gains and losses on disposals are determined by comparing the proceeds with the carrying amount and are recognized within “Other operating expenses, net” in the income statement.

Leases

Leases in which a significant portion of the risks and rewards of ownership are retained by the lessor are classified as operating leases. Payments made under an operating lease (net of any incentive received from the lessor) are charged to the income statement on a straight line basis over the period of the lease.

The subsidiaries lease certain property, plant and equipment. Leases of property, plant and equipment, where the Company has substantially all the risks and rewards of ownership, are classified as finance leases. Finance leases are capitalized at the inception of the lease at the lower of the fair value of the leased item and the present value of the minimum lease payments.

Each lease payment is allocated between the liability and finance charges. The corresponding rental obligations, net of finance charges, are included in “Loans and financing”.

The interest element of the finance cost is charged to the income statement over the lease period so as to give a constant periodic rate of interest on the remaining balance of the liability for each period. The property, plant and equipment acquired under finance leases are depreciated over the shorter of the asset’s useful life and the lease term.

Impairment of non-financial assets

The Company assesses, at each reporting date, whether there is an indicator that an asset or cash generating unit (“CGU”) may be impaired. If any indication exists, such as volumes and prices reductions or unusual events that can affect the business for example, the Company estimates the asset’s or CGU’s recoverable amount. The recoverable amount is the higher of an asset’s or CGU’s fair value less cost of disposal and its value in use. The recoverable amount is determined for an individual asset, unless the asset does not generate cash inflows that are largely independent of those from other assets or groups of assets, in which case, the asset is tested as part of a larger CGU to which it belongs. If the carrying amount of an asset or CGU exceeds its recoverable amount, the asset or CGU is considered impaired and is written down to its recoverable amount. Non-financial assets other than goodwill that were adjusted due to impairment are subsequently reviewed for possible reversal of the impairment at each reporting date.

(a)Analysis

	2017
					Machinery,						Assets and
	Land and		Dam and		equipment and				Furniture and		projects under		Asset retirement
	improvements		buildings		facilities		Vehicles		fixtures		construction		obligation (ARO )		Mining projects		Other		Total
Balance at the beginning of the year
Cost	24.036		980.242		2.466.265		22.263		6.895		219.254		132.824		271.466		7.345		4.130.590
Accumulated depreciation	(257	)	(435.372	)	(1.485.939	)	(20.440	)	(4.443	)	—		(96.108	)	(102.828	)	(6.741	)	(2.152.128	)
Net balance	23.779		544.870		980.326		1.823		2.452		219.254		36.716		168.638		604		1.978.462
Acquisitions	46		100		5.761		272		307		185.688		4.303		240		—		196.717
Disposals	(930	)	(92	)	(2.915	)			(121	)	(6.917	)	—		—		(7	)	(10.982	)
Depreciation	(22	)	(34.175	)	(142.519	)	(1.174	)	(509	)	—		(5.834	)	(11.121	)	(83	)	(195.437	)
Exchange variation losses	(231	)	(4.309	)	(6.381	)	(101	)	(9	)	(3.965	)	(1.839	)	(2.115	)	(8	)	(18.958	)
Transfers	1.573		71.152		83.297		2.236		131		(158.559	)	—		2.841		—		2.671
Cost and interest revision	—		—		—		—		—		—		43.789		—		—		43.789
Transfers of assets held for sale	—		—		252		—		—		—		—		—		—		252
Balance at the end of the year	24.215		577.546		917.821		3.056		2.251		235.501		77.135		158.483		506		1.996.514
Cost	24.490		1.030.686		2.422.254		21.135		6.743		235.501		178.662		243.938		7.177		4.170.586
Accumulated depreciation	(275	)	(453.140	)	(1.504.433	)	(18.079	)	(4.492	)	—		(101.527	)	(85.455	)	(6.671	)	(2.174.072	)
Net balance at the end of the year	24.215		577.546		917.821		3.056		2.251		235.501		77.135		158.483		506		1.996.514
Average annual depreciation rates - %	—		4		7		24		10		—		5		8		—		—

					Machinery,						Assets and
	Land and		Dam and		equipment and				Furniture and		projects under		Asset retirement
	improvements		buildings		facilities		Vehicles		fixtures		construction		obligation (ARO)		Mining projects		Other		Total
Balance at the beginning of the year
Cost	20,657		816,001		2,223,583		20,551		6,278		206,094		116,695		246,208		6,079		3,662,146
Accumulated depreciation	(85	)	(332,034	)	(1,259,830	)	(18,066	)	(3,441	)	—		(74,229	)	(85,544	)	(5,563	)	(1,778,792	)
Net balance	20,572		483,967		963,753		2,485		2,837		206,094		42,466		160,664		516		1,883,354
Acquisitions	—		—		489				2		151,302		148		28,915		—		180,856
Disposals	(46	)	(593	)	(1,525	)	(95	)	(37	)	(42	)	—		(11,000	)	(1	)	(13,339
Depreciation	(20	)	(31,145	)	(145,450	)	(1,487	)	(477	)	—		(7,301	)	(14,096	)	(67	)	(200,043
Reversal of provision for asset impairment (i)											979								979
Exchange variation gains	2,274		38,640		64,510		259		43		16,987		4,589		2,652		139		130,093
Transfers	999		54,001		98,801		661		84		(156,066	)			1,503		17
Cash flow review and restatement of interest rates	—		—		—		—		—		—		(3,186	)	—		—		(3,186	)
Assets transferred to held for sale	—		—		(252	)	—		—		—		—		—		—		(252	)
Balance at the end of the year	23,779		544,870		980,326		1,823		2,452		219,254		36,716		168,638		604		1,978,462
Cost	24,036		980,242		2,466,265		22,263		6,895		219,254		132,824		271,466		7,345		4,130,590
Accumulated depreciation	(257	)	(435,372	)	(1,485,939	)	(20,440	)	(4,443	)	—		(96,108	)	(102,828	)	(6,741	)	(2,152,128	)
Net balance at the end of he year	23,779		544,870		980,326		1,823		2,452		219,254		36,716		168,638		604		1,978,462
Average annual depreciation rates -%	—		4		7		21		11		—		7		8		—		—

Assets pledged as collateral are shown in Note 16, and refer only to BNDES financings.

(i)The Company assesses at each balance sheet date whether there is objective evidence that any item of property, plant and equipment is impaired. No impairment was identified during 2017.

(b)Leases

The carrying amount as of December 31, of land and equipment acquired through finance leases is the following:

	2017		2016
Cost	19,763		13,794
Accumulated depreciation	(10,930	)	(9,657	)
	8,833		4,137

(c)Assets and projects under constructions

The balance of construction in progress mainly comprises projects for the expansion and optimization of the Company’s Plant and mines, as described below:

	2017	2016
Mining projects	101,922	91,174
Acquisition and renovation of equipment	42,239	52,284
Security, health and enviroment projects	35,858	44,674
New production line construction	25,477	5,472
Information technology	3,084	151
Modernization and increased production projects	10,563	10,004
Other	16,358	15,495
	235,501	219,254

During the year, borrowing charges capitalized as part of construction in progress totaled US$ 10,630 (2016: US$ 6,493). The average capitalization rate used was 0.68% per month (2016: 0.69% per month).

Suspended projects are continuously assessed, and if there is any indication of impairment, a provision might be recognized. In regards to remaining balance presented above, which was not provided for as an impairment loss, the Company believes that it will resume the project and/or use this asset in other production lines.

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Intangible assets

12 Months Ended

Dec. 31, 2017

Intangible assets

Intangible assets

15Intangible assets

Accounting policy

Classification

(i)Goodwill

For the purpose of impairment testing, the recoverable amount goodwill is allocated to a CGU that is the lowest level with the Group at which goodwill is monitored. If the recoverable amount of the asset (or CGU) is estimated to be less than its carrying amount, the carrying amount of the asset (or CGU) is reduced to its recoverable amount. The difference between the carrying amount and recoverable amount is recognized as an impairment loss in the income statement.

(ii)Rights over natural resources

Costs for the acquisition of rights to explore and develop mineral properties are capitalized and amortized using the straight line method over their useful lives. Useful lives consider the period of extraction for both mineral reserves and mineral resources, which includes a portion of the Company’s inferred resources in the Company’s mining operations in Peru. These mining operations represent over 98% of the Company’s total right to use natural resources.

Management considers that in the case of the rights to use natural resources, which relate almost exclusively to the Peruvian acquired assets, the use of only proven and probable reserves does not provide a realistic indication of the useful life of the mine. In this case management is confident based on testing, continuity of the ore bodies and conversion experience that further inferred resources will be converted into measured and indicated resources, and if they are economically recoverable, that such inferred resources can also be classified as proven and probable reserves. Management is approaching economic decisions affecting the mine on this basis, but has chosen to delay the work required to designate them formally as reserves in accordance with its annual testing plans. In assessing which inferred resources to include so as to best reflect the useful life of the mine, management considers inferred resources that have been included in the strategic mine plan. To be included in the strategic mine plan, inferred resources need to be above the cutoff grade set by management, which means that such resource expect to be economically mined and is therefore commercially viable. This consistent systematic method for inclusion in the strategic mine plan takes management’s view of the mineral price, extraction costs as well as cost inflation into account. In order to convert these inferred resources into measured and indicated resources, the Company would have to conduct additional drilling.

Additional confidence in the existence, commercial viability and economical recovery of such resources may be based on historical experience and available geological information, such as geological information obtained from other operations that are adjoining the Company’s as well as where the Company mines continuations of these other operations’ orebodies. This is in addition to the drilling results obtained by the Company and management’s knowledge of the geological setting of the surrounding areas, which would enable simulations and interpolations to be done with a reasonable degree of accuracy. In instances where management is able to demonstrate the economic recovery of such resources with a high level of confidence based on the specific circumstances, such additional resources, which may also include certain, but not all, of the inferred resources, are included in the calculation of amortization.

Thus, although there is less assurance that mineral resources will eventually be realized as compared to proven and probable reserves, a portion of inferred resources are considered to be economically valuable based on our historical experience and are considered in the useful life of the mine for accounting purposes, as there has been a continuous conversion of the inferred resources into measured and indicated, and then to mineral reserves. The annual conversion rate from inferred mineral resources into measured and indicated mineral resources for the Company’s mining operations in Peru was approximately 97% in 2015, 100% in 2016 and 100% in 2017. The Company included approximately 70% of the Company’s inferred resources in Peru when calculating the expected life of mine for purposes of the period of amortization.

Considering the nature of the Company’s production year on year, the expense calculated under the straight line method is not considered to be materially different to what it would be calculated under the unit of production method. Once the mine is operational, these costs are amortized and considered as a cost of production.

(iii)Stripping costs

In mining operations related to the metal business, it is necessary to remove overburden and other waste to gain access to mineral ore deposits. The process of mining overburden and waste materials is referred to as stripping. During the development of a mine, before production commences, when the stripping activity asset improves access to the ore body, the component of the ore body for which access has been improved can be identified and the costs can be measured reliably, the stripping activity asset is capitalized as part of the investment in the construction of the mine, accounted for as part of intangible assets, and subsequently amortized over the life of the mine on a units of production basis.

Stripping costs incurred during the production phase of operations are treated as a production cost that forms part of the cost of inventory.

(iv)Costs of exploration

The Company capitalizes the costs of exploration when the existence of proven and probable reserves is determined. These costs are amortized using the estimated useful lives of the mining property from the time when commercial exploitation of the reserves begins.

When Management determines that no future economic benefits are expected from the mining property, the accumulated exploration costs are charged to “Other operating expenses, net”.

(v)Mineral studies and research expenditures

Mineral studies and research expenditure are considered operating expenses until such time as the economic feasibility of the commercial exploitation of a certain mine is proven. Once feasibility is proven, the expenditure incurred is capitalized within mine development costs in “construction in progress — property, plant and equipment”. When the mine is operational, the cumulative costs capitalized in relation to exploitation rights are reclassified from “constructions in progress” to “mining projects” and subsequently amortized over the life of the mine on a units of production basis and included in the cost of the product. The capitalized construction costs relating to the plant are reclassified to “equipment and facilities”.

(vi)Use of public assets

Represent the amounts established in the concession contracts regarding the rights to hydroelectric power generation (onerous concession) under use of public assets (“UBP”) agreements.

The accounting entries are made considering the time the installation permit is released, regardless of the disbursement schedule established in the contract. The initial recording of this liability (obligation) and intangible asset (concession rights) corresponds to the amounts of future obligations brought to present value (present value of the cash flow of future payments).

The amortization of the intangible asset is calculated on a straight line basis over the remaining period of the concession. The financial liability is restated at the index established and the adjustment to present value due to the passage of time, reduced by the payments made.

(vii)Computer software

Computer software licenses acquired are recorded as intangible assets on the basis of the costs incurred to acquire and bring to use the specific software. These costs are amortized over the estimated useful life of the software (three to five years).

Costs associated with maintaining computer software programs are recognized as an expense as incurred.

Critical accounting estimates and judgments

(i)Determination of mineral reserves as basis to determine Life of Mine

Mineral reserves are resources known to be economically feasible for extraction under conditions at the applicable measurement date. The amortization method and rates applied to the rights to use natural resources reflect the pattern in which the benefits are expected to be used by the Company and based on the estimated life of mine. Any changes to life of mine, based on mineral reserves, mineral resources estimates and mining plan, may affect prospective amortization rates and assets carrying values.

The process of estimation of mineral reserves and mineral resources is based on a technical evaluation, which includes accepted geological, geophysics, engineering, environmental, legal and economic estimates, which when evaluated in aggregate can have relevant impact in the economic viability of the mineral reserves. The Company uses various assumptions with respect to expected future conditions, such as ore prices, inflation rate, exchange rates, technology improvements, production costs, among others. Reserve estimates are reviewed periodically and any changes are adjusted to reflect life of mine and consequently adjustments to amortization periods.

The Company recorded in the year December 31, 2017 amortization of rights to use natural resources in the amount of US$ 74,024 (2016: US$ 74,013), with an average rate of 5.0% per year.

The Company included in the useful life for amortization of rights to use natural resources certain inferred resources when performing the amortization calculation for its Peruvian operations, where proven and probable reserves alone do not provide a realistic indication of the useful life of mine (and related assets). The Company classifies measured, indicated and inferred resources based on the definitions of the Canadian Institute of Mining, Metallurgy and Petroleum (or CIM) Definition Standards for Mineral Resources and Mineral Reserves (or the 2014 CIM Definition Standards).

Had the Company performed the calculation of amortization using only proven and probable reserves and measured and indicated resources (and excluding inferred resources), amortization for 2017 would have amounted to US$ 82,270 (2016: US$ 82,594), compared with the reported totals of US$ 72,878 (2016: US$72,878) related to Peruvian operations. This would have resulted in additional amortization of US$ 9,392 in 2017 (2016: US$9,716).

The future conversion of inferred resources is inherently uncertain and involves judgement. Actual outcomes may vary from these judgements and estimates and such changes could have a material impact on the Company’s results.

(ii)Use of public assets

The amount related to the use of a public asset is originally recognized as a financial liability (obligation) and as an intangible asset (right to use a public asset) which corresponds to the amount of the total annual charges over the period of the agreement discounted to present value (present value of the future cash flow).

(iii)Impairment of goodwill

Goodwill is tested for impairment annually, as at September 30, and when circumstances indicate that the carrying value may be impaired. Impairment is determined for goodwill by assessing the recoverable amount of each CGU (or group of CGUs) to which the goodwill relates. Where the recoverable amount of the CGU is less than its carrying amount including goodwill, an impairment loss is recognized. The recoverable amount is the higher of an asset’s fair value less costs to sell and its value in use. For the purposes of assessing impairment, assets are grouped at the lowest level for which there is separately identifiable cash flow (CGU level). Impairment losses relating to goodwill cannot be reversed in future periods.

(a)Analysis

	2017
	Goodwill		Rights to use natural resources		Software		Use of public assets		Assets and projects under construction		Other		Total
Balance at the beginning of the year
Cost	675,561		1,673,091		1,507		11,581		6,974		35,053		2,403,767
Accumulated amortization	—		(469,381	)	(1,106	)	(4,159	)	—		(25,969	)	(500,615	)
Net balance	675,561		1,203,710		401		7,422		6,974		9,084		1,903,152
Acquisitions	—		—		921		—				—		921
Disposals	—		—		(36	)	—				—		(36	)
Amortization	—		(74,024	)	(576	)	(394	)			(23	)	(75,017	)
Exchange variation losses	(2,274	)	(682	)	(21	)	(96	)	(424	)	(133	)	(3,630	)
Transfers	—		—		4,768		—		(6,546	)	(893	)	(2,671	)
Balance at the end of the year	673,287		1,129,004		5,457		6,932		4		8,035		1,822,719
Cost	673,287		1,672,931		21,823		11,410		4		28,847		2,408,302
Accumulated amortization	—		(543,927	)	(16,366	)	(4,478	)	—		(20,812	)	(585,583	)
Net balance at the end of the year	673,287		1,129,004		5,457		6,932		4		8,035		1,822,719
Average annual amortization rates %	—		5		20		3		—		—		—

	2016
	Goodwill	Rights to use natural resources		Software		Use of public assets		Assets and projects under construction		Other		Total
Balance at the beginning of the year
Cost	674,769	1,669,901		469		9,666		5,238		30,018		2,390,061
Accumulated amortization	—	(395,665	)	(340	)	(3,148	)	—		(22,029	)	(421,182	)
Net balance	674,769	1,274,236		129		6,518		5,238		7,989		1,968,879
Acquisitions	—			—		—		2,133				2,133
Amortization	—	(74,013	)	(73	)	(363	)	—		(542	)	(74,991	)
Exchange variation gains (losses)	792	3,487		(41	)	1,267		—		1,626		7,131
Transfers	—	—		386		—		(397	)	11
Balance at the end of the year	675,561	1,203,710		401		7,422		6,974		9,084		1,903,152
Cost	675,561	1,673,091		1,507		11,581		6,974		35,053		2,403,767
Accumulated amortization	—	(469,381	)	(1,106	)	(4,159	)	—		(25,969	)	(500,615	)
Net balance at the end of the year	675,561	1,203,710		401		7,422		6,974		9,084		1,903,152
Average annual amortization rates %	—	5		20		3		—		—		—

The Company assesses at each balance sheet date whether there is objective evidence that any item of intangible is impaired. No impairment was identified during 2017.

(b)Goodwill on acquisitions

The goodwill is allocated in accordance with the group of CGUs. For 2017 the total goodwill registered was US$ 673,287 (2016: US$ 675,561).

(c)Impairment testing of goodwill

The Company assesses the recovery of the carrying amount of goodwill of each CGU based on its value in use or fair value, using a discounted cash flow model. The process of estimating the value in use and fair value involves the use of assumptions, judgment and projections for future cash flows. Management’s assumptions and estimates of future cash flow used for the Company’s impairment testing of goodwill and non-financial assets are subject to risk and uncertainties, particularly for markets subject to higher volatilities, which are partially or totally outside the Company’s control.

The calculations used for the impairment testing are based on discounted cash flow models as at September 30, 2017 and are based on market assumptions, such as LME prices, market consensus models and other available data regarding global demand. The discount factor applied to the discounted cash flow model is the Company’s Weighted Average Cost of Capital for the applicable region, adjusted for country-specific risk factors. These calculations use cash flow projections, before taxes on income, based on financial budgets for a five-year period approved by management and is extended until the end of the mine life (LOM — life of mine). The Company does not use growth rates in the cash flow projections of the terminal value. The discount rate reflect specific risk relating operating segment. No material changes occurred between the cutoff date used for impairment testing (September 30, 2017) and the December 31, 2017.

The following table summarizes the main assumptions used for the impairment testing of goodwill:

	Key Assumptions
Zinc (US$ per ton)	2,509
Copper (US$ per ton)	6,362
Discount Rate	10.6	%

	LOM (Years)
Mines	from 7 to 12
Greenfield	from 13 to 27

The carrying amount at September 30, 2017 was US$ 1,868,238. The recoverable amount exceeded the carrying value, therefore no impairment was recognized in the consolidated financial statements.

The sensitivity analysis was performed on key assumptions used for impairment testing for the NEXA PERU CGU.

If the long-term metal’s price (LME) assumptions used in the fair value calculation had been 5% lower than management’s estimates at September 30, 2017 (US$/ton 2,383 instead of US$/ton 2,509) the Company would have had to recognize an impairment against the carrying amount of this CGU of approximately US$ 95,238. If the discount rate applied to the cash flow projections had been 2% higher than management’s estimates, the Company would have had to recognize an impairment against the carrying amount of approximately US$ 102,238.

Although the discounted cash flow model determined that there is a little headroom with respect to the overall results of the testing, in the absence of an objective triggering event for impairment as at the balance sheet date, Management kept the recoverable amounts with respect to goodwill unaltered as at this date.

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Loans and Financings

12 Months Ended

Dec. 31, 2017

Loans and financings

Loans and financings

16Loans and financings

Accounting policy

Loans and financings are recognized initially at fair value, net of transaction costs incurred, and are subsequently carried at amortized cost. Any difference between the proceeds (net of transaction costs) and the total amount payable is recognized in the income statement over the period of the loans using the effective interest rate method.

Loans and financings are classified as current liabilities unless the Company has the unconditional right to defer repayment of the liability for at least 12 months after the reporting period.

Fees paid on the establishment of loan facilities are recognized as transaction costs of the loan to the extent that it is probable that some or all of the facility will be drawn down. In this case, the fee is deferred until the drawdown occurs. To the extent that there is no evidence that it is probable that some or all of the facility will be drawn down, the fee is capitalized as a prepayment for liquidity services and amortized over the period of the facility to which it relates.

Loans and financing costs directly related to the acquisition, construction or production of a qualifying asset that requires a substantial period of time to prepare for its intended use or sale are capitalized as part of the cost of that asset when it is probable that future economic benefits associated with the item will flow to the Company and costs can be measured reliably. The other loans and financing costs are recognized as financial expenses in the period in which they are incurred.

(a)Analysis and maturity profile

		Current		Non-current		Total		Fair value
Type	Average annual charges	2017	2016	2017	2016	2017	2016	2017	2016
Eurobonds - USD	5.19% fixed USD	8,778	4,054	1,032,664	343,000	1,041,442	347,054	1,120,901	342,156
Debt with banks	LIBOR 3M + 2.57% /LIBOR 6M + 2.51%	435	24,038	199,179	662,743	199,614	686,781	214,293	712,371
BNDES	TJLP + 2.68% / 4.74% fixed BRL / SELIC + 2.78% / UMBNDES + 2.44%	19,795	32,619	73,653	67,672	93,448	100,291	85,969	86,908
Debentures	107.77% CDI	8,885	504	32,403	3,822	41,288	4,326	41,405	4,235
Export credit note	118.00% CDI / LIBOR 3M + 1.85%	1,102	—	61,622	—	62,724	—	64,058	—
FINEP	TJLP + 0.68%	677	682	2,062	2,743	2,739	3,425	2,640	3,038
FINAME	4.59% fixed BRL	398	407	1,383	1,804	1,781	2,211	1,604	1,828
Other	5,93% fixed USD	771	297	3,492	—	4,263	297	4,262	349
		40,841	62,601	1,406,458	1,081,784	1,447,299	1,144,385	1,535,132	1,150,885
Current portion of long term loans and financing (principal)		28,019	57,137
Interest on loans and financing		12,822	5,464
		40,841	62,601

BNDES	—	Brazilian National Bank for Economic and Social Development
BRL	—	Brazilian Reais
CDI	—	Interbank Deposit Certificate
FINAME	—	Government Agency for Machinery and Equipment Financing
TJLP	—	Long Term Interest Rate set by the Brazilian National Monetary Council, the TJLP is the basic cost of financing of the BNDES
UMBNDES	—	Monetary unit of the BNDES, reflecting the weighted basket of currencies of foreign currency debt obligations. At December 31, 2017, the basket was 99% comprised of US Dollars.
SELIC	—	Brazilian System for Clearance and Custody
FINEP	—	Funding Authority for Studies and Projects

The maturity profile of loans and financing at December 31, 2017, was as follows:

	Principal amount
	2018	2019	2020	2021	2022	2023	2024	As from 2025	Total
Eurobonds - USD	—	—	—	—	—	343,000	—	700,000	1,043,000
Debt with banks	—	31,111	84,444	84,444	—	—	—	—	199,999
BNDES	19,732	23,379	16,288	12,703	9,500	5,284	3,067	4,251	94,204
Debentures	8,119	8,119	8,119	8,119	8,119	—	—	—	40,595
Export credit note	—	—	61,623	—	—	—	—	—	61,623
FINEP	669	669	669	669	56	—	—	—	2,732
FINAME	395	392	374	315	231	70	1		1,778
Other	772	818	866	918	889	—	—	—	4,263
	29,687	64,488	172,383	107,168	18,795	348,354	3,068	704,251	1,448,194

	Interest accrual and costs
	2018	2019		2020		2021		2022		2023		2024		As from 2025		Total
Eurobonds - USD	8,778	(1,177	)	(1,227	)	(1,280	)	(1,337	)	(1,172	)	(1,160	)	(2,983	)	(1,558	)
Debt with banks	435	(281	)	(281	)	(258	)	—		—		—		—		(385	)
BNDES	63	(225	)	(179	)	(165	)	(109	)	(60	)	(34	)	(47	)	(756	)
Debentures	767	(31	)	(25	)	(9	)	(9	)	—		—		—		693
Export credit note	1,101	—		—		—		—		—		—		—		1,101
FINEP	7	—		—		—		—		—		—		—		7
FINAME	3	—		—		—		—		—		—		—		3
Other	—	—		—		—		—		—		—		—
	11,154	(1,714	)	(1,712	)	(1,712	)	(1,455	)	(1,232	)	(1,194	)	(3,030	)	(895	)

	Total
	2018	2019		2020		2021		2022		2023	2024		As from 2025	Total
Eurobonds - USD	8,778	(1,177	)	(1,227	)	(1,280	)	(1,337	)	341,828	(1,160	)	697,017	1,041,442
Debt with banks	435	30,830		84,163		84,186		—		—	—		—	199,614
BNDES	19,795	23,154		16,109		12,538		9,391		5,224	3,033		4,204	93,448
Debentures	8,886	8,088		8,094		8,110		8,110		—	—		—	41,288
Export credit note	1,101	—		61,623		—		—		—	—		—	62,724
FINEP	676	669		669		669		56		—	—		—	2,739
FINAME	398	392		374		315		231		70	1		—	1,781
Other	772	818		866		918		889		—	—		—	4,263
	40,841	62,774		170,671		105,456		17,340		347,122	1,874		701,221	1,447,299
	4%	4%		12%		7%		1%		24%	0%		48%	100%

(b)Changes

	2017		2016
Balance at the beginning of the year	1,144,385		1,056,210
Payments	(537,254	)	(483,100	)
New loans and financing	837,819		550,966
Exchange variation	(2,873	)	17,834
Interest accrual	69,481		38,511
Interest paid	(57,038	)	(35,689	)
Addition of borrowing fees, net of amortization	(7,221	)	(347	)
Balance at the end of the year	1,447,299		1,144,385

(c)Analysis by currency

	Current		Non-current		Total
	2017	2016	2017	2016	2017	2016
US Dollar	13,260	31,496	1,272,223	1,013,988	1,285,483	1,045,484
Real	27,471	28,170	134,235	66,954	161,706	95,124
Currency basket	110	2,935		842	110	3,777
	40,841	62,601	1,406,458	1,081,784	1,447,299	1,144,385

(d)Analysis by index

	Current		Non-current		Total
	2017	2016	2017	2016	2017	2016
Fixed rate	11,192	6,466	1,038,459	346,997	1,049,651	353,463
LIBOR	610	24,037	230,573	662,743	231,183	686,780
TJLP	12,509	23,078	35,341	41,632	47,850	64,710
UMBNDES	3,211	6,042	5,496	9,087	8,707	15,129
CDI	9,811	504	62,632	3,822	72,443	4,326
BNDES Selic	3,508	2,474	33,957	17,503	37,465	19,977
	40,841	62,601	1,406,458	1,081,784	1,447,299	1,144,385

(e)Guarantees and covenants

At December 31, 2017, US$ 1,063,784 (2016: US$ 780,579) of the borrowing was guaranteed by sureties, US$ 1,781 (2016: US$ 2,211) by fiduciary liens and the total amount of debentures is insured by real collateral.

The Company has borrowings agreements that are subject to financial covenants at the Company´s level, and also at the level of its controlling shareholder, VSA (by virtue that VSA is the guarantor of the BNDES borrowings). The borrowing agreements of debt with banks are subject to compliance with financial ratio rules (covenants), such as: (i) the gearing ratio (net debt/adjusted EBITDA); (ii) the capitalization ratio (total debt/total debt + equity or equity/total assets); and (iii) interest coverage ratio (cash + adjusted EBITDA/interest + short-term debt). When applicable, these compliance obligations are standardized for all borrowing agreements.

At December 31, 2017, the Company and its controlling shareholder were in compliance with all applicable covenants. If VSA breaches its covenants, the Company needs to present to BNDES a guarantee of 130% of the amount borrowed.

New borrowing

On May 4, 2017, the Company issued a US$ 700,000 ten-year bond. See note 1 (ii) for more details.

(f)Subsidiary bonds

The Company’s subsidiary NEXA PERU conducted a bond offering in the international market for US$ 350,000 on March 28, 2013. These financial instruments have a term of ten years and will be redeemed on March 28, 2023, at an annual fixed interest rate of 4.625% to be paid semi-annually. A portion of the proceeds obtained was used to settle bank borrowings.

(g)Revolving Credit Facility

The Company contracted in June 2015 a revolving credit facility amounting US$ 225,000, which falls due in June 2020. The credit is available and can be used anytime. As at December 31, 2017, the Company did not use the credit facility.

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Confirming payables

12 Months Ended

Dec. 31, 2017

Confirming payables

Confirming payables

17Confirming payables

The Company’s subsidiaries entered into agreements extending payment terms from 90 to 180 days with a number of suppliers. These suppliers have the option to discount their receivables with banks. At December 31, 2017, accounts payable amounting to US$ 111,024 (2016: 102,287) were included in such agreements.

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Salaries and payroll charges

12 Months Ended

Dec. 31, 2017

Salaries and payroll charges

Salaries and payroll charges

18Salaries and payroll charges

	2017	2016
Direct remuneration and social charges	21,357	18,655
Provision for profit sharing and other payable	58,441	51,367
	79,798	70,022

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Taxes payable

12 Months Ended

Dec. 31, 2017

Taxes payable

Taxes payable

19Taxes payable

	2017	2016
Corporate taxes on income	24,108	18,145
Special mining lien and special mining tax	8,731	664
Withholding taxes	3,737	3,494
Value-added tax on sales and services	366	6,393
Social contribution on revenue	185	182
Social integration program	39	39
Other	3,943	931
	41,109	29,848

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Current and deferred taxes on income

12 Months Ended

Dec. 31, 2017

Current and deferred taxes on income.

Current and deferred taxes on income

20Current and deferred taxes on income

Accounting policy

The taxes on income benefit or expense for the period comprises current and deferred taxes.  Taxes on profit are recognized in the income statement, except to the extent that they relate to items recognized in comprehensive income or directly in shareholders’ equity.  In such cases, the taxes are also recognized in comprehensive income or directly in shareholders’ equity respectively.

The current and deferred taxes on income is calculated on the basis of the tax laws enacted or substantively enacted up to balance sheet date in the countries where the entities operate and generate taxable income. Management periodically evaluates positions taken by the Company in the taxes on income returns with respect to situations in which the applicable tax regulations are subject to interpretation. It establishes provisions where appropriate on the basis of amounts expected to be paid to the tax authorities.

The current taxes on income is presented net, separated by taxpaying entity, in liabilities when there are amounts payable, or in assets when the amounts prepaid exceed the total amount due on the reporting date.

Deferred tax assets are recognized only to the extent it is probable that future taxable profits will be available against which the temporary differences and/or tax losses can be utilized.

Deferred tax assets and liabilities are offset when there is a legally enforceable right and an intention to offset them in the calculation of current taxes, generally when they are related to the same legal entity and the same tax authority. Accordingly, deferred tax assets and liabilities in different entities or in different countries are generally presented separately, and not on a net basis.

Deferred tax liabilities and assets are not recognized for temporary differences between the carrying amounts and tax bases of investments in foreign operations where the Company is able to control the timing of the reversal of the temporary differences and it is probable that the differences will not be reversed in the near future.

Deferred taxes on income is provided in full, using the liability method, on temporary differences arising between the tax bases of assets and liabilities and their carrying amounts in the consolidated financial statements. However, deferred tax liabilities are not recognized if they arise from the initial recognition of goodwill. Deferred taxes on income is also not accounted for if it arises from the initial recognition of an asset or liability in a transaction other than a business combination that, at the time of the transaction, affects neither the accounting nor the taxable profit or loss. Deferred taxes on income is determined using tax rates (and laws) that have been enacted or substantially enacted by the end of the reporting period and are expected to apply when the related deferred taxes on income asset is realized or the deferred taxes on income liability is settled.

Critical accounting estimates and judgments

The Company is subject to taxes on income in all countries in which it operates.  Significant judgment is required in determining the worldwide provision for taxes on income.  There are many transactions and calculations for which the ultimate tax determination is uncertain.  The Company also recognizes liabilities for anticipated tax audit issues based on estimates of whether additional taxes will be due. Where the final tax outcome of these matters is different from the amounts that were initially recorded, such differences will impact the current and deferred tax assets and liabilities in the period in which such determination is made.

(a)Reconciliation of taxes on income expenses

	2017		2016		2015
Profit before taxation	271,459		208,892		(178,257	)
Standard rate (i)	27.08	%	29.22	%	29.22	%
Taxes on income at standard rates	(73,511	)	(61,038	)	52,087
Share in the results of investees	16		(46	)	(75	)
Difference in tax rate for subsidiaries outside Luxembourg	(19,912	)	(11,425	)	4,138
Re-measurement of deferred tax - change in Peru tax rate (ii)	—		(41,588	)	—
Taxes on dividend received from foreign sudisdiary	(8,299	)	—		—
Taxes of prior years (iii)	(5,381	)	1,127		—
Difference arising on carrying non-current assets using a different base	12,144		2,458		(18,310	)
Other permanent (additions) exclusions, net	(11,251	)	12,129		939
Taxes on income	(106,194	)	(98,383	)	38,779
Current	(125,691	)	(75,282	)	(62,758	)
Deferred	19,497		(23,101	)	101,537
Taxes on income on the income statement	(106,194	)	(98,383	)	38,779

(i) The combined applicable income tax rate (including an unemployment fund contribution) was 29.22% for the fiscal year ending 2016. On December 14, 2016, the Luxembourg government approved bill of law 7020, in the 2017 tax reform bill. Among other changes included in the 2017 tax reform bill, the main change announced was the decrease of the income tax rate to 27.08% in 2017 and to 26.01% from 2018 onwards.

(ii) The Peruvian companies pay their taxes based on the general regime of taxation, which provides for a progressive decrease in the tax rate after the year 2015. Until 2014 the rate was 30%, while for 2015 and 2016 the rate was 28%, for 2017 and 2018 the rate was expected to be 27% and from 2019 onwards the rate was expected to be 26%. However, in December 2016, the tax rate changed to 29.5% applicable from January 1, 2017. The change impacted the deferred tax mainly over the purchase price allocation of NEXA PERU.

(iii) Income taxes paid or recovered in Austria by our subsidiary Votorantim GmbH which are related to prior years.

(b)Analysis of deferred tax balances

	2017		2016
Tax credits on non-operating losses	104,100		102,555
Tax credits on temporary diferences
Exchange variation losses	79,430		84,536
Environmental liabilities	28,504		27,206
Asset retirement obligation	23,990		22,085
Tax, civil and labor provisions	15,666		16,904
Other provisions	12,481		13,792
Provision for profit sharing	6,521		6,322
Provision for inventory losses	4,395		5,202
Use of public assets	4,093		4,305
Provision for impairment of trade receivables	1,110		743
Other	5,028		1,863
Tax debits on temporary diferences
Adjustment to present value	(1,253	)	(1,269	)
Capitalized interest	(10,624	)	(7,184	)
Accelerated depreciation and adjustment of useful lives	(28,371	)	(20,748	)
Depreciation and amortization of fair value adjustment to PP&E and intangible assets	(344,531	)	(363,604	)
Other	(957	)	(12	)
	(100,418	)	(107,304	)
Net deferred tax assets related to the same legal entity	224,513		221,304
Net deferred tax liabilities related to the same legal entity	(324,931	)	(328,608	)
	(100,418	)	(107,304	)

As of 31 December 2017, the Company has certain unutilised tax losses resulting from its holding activities in Luxembourg. Given uncertainty in the future profitability, no deferred tax assets have been recognised in respect of these losses.

(c)Effects of deferred tax and taxes on profit or loss for the year and other comprehensive income

	2017		2016
Balance at beginning of year	(107,304	)	(119,351	)
Effect on income for the period	19,497		(23,101	)
Effect on comprehensive income	(4,119	)	8,825
Exchange variation	(8,492	)	26,323
Balance at end of year	(100,418	)	(107,304	)

(d)Tax effects relating to components of other comprehensive income (loss)

	2017				2016
	Before tax	(Charge) credit		After tax	Before tax		(Charge) credit	After tax
Operating cash flow hedge accounting	16,675	(4,119	)	12,556	(25,081	)	8,825	(16,256	)

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Provisions

12 Months Ended

Dec. 31, 2017

Provisions

Provisions

21Provisions

Accounting policy

Provisions for tax, civil, labor, environmental and legal claims

Provisions for legal claims (labor, civil, tax and environmental) are recognized when: (i) the Company has a present legal or constructive obligation as a result of past events; (ii) it is probable that an outflow of resources will be required to settle the obligation; and (iii) the amount can be reliably estimated. Provisions do not include future operating losses.

Where there is a number of similar obligations, the likelihood that an outflow will be required in settlement is determined by considering the class of obligations as a whole. A provision is recognized even if the likelihood of an outflow with respect to any one item included in the same class of obligations may be small.

Provisions are measured at the present value of the expenditure expected to be required to settle the obligation using a pre-tax rate that reflects current market assessments of the time value of money and the risks specific to the obligation. The increase in the provision due to the passage of time is recognized as “Financial expenses”.

Asset retirement obligation

The Company recognizes a provision for environmental restoration and for the closure of operating units that correspond to its legal obligation to restore the environment at the termination of its operations.

Provision is made for asset retirement, restoration and environmental costs when the obligation occurs, based on the net present value of estimated future costs with, where appropriate, probability weighting of the different remediation and closure scenarios. The ultimate cost of closedown and restoration is uncertain, and management uses its judgment and experience to determine the potential scope of rehabilitation work required and to provide for the costs associated with that work. Adjustments are made to provisions when the range of possible outcomes becomes sufficiently narrow to permit reliable estimation.

Cost estimates can vary in response to many factors including: changes to the relevant legal or local/national government ownership requirements and any other commitments made to stakeholders; review of remediation and relinquishment options; the emergence of new restoration techniques and the effects of inflation. Experience gained at other mine or production sites is also a significant consideration, although elements of the restoration and rehabilitation of each site are relatively unique to the site and, in some cases, there may be relatively limited restoration and rehabilitation activity and historical precedent against which to benchmark cost estimates. External experts support the cost estimation process where appropriate.

Cost estimates are updated throughout the life of the operation aligned with Internal Policies and these Internal Policies themselves are also subject to periodical updates to maintain these in line with international best practices. The expected timing of expenditure included in cost estimates can also change, for example in response to changes to expectations relating to ore reserves and mineral resources, production rates, operating licenses or economic conditions. Expenditure may occur before and after closure and can continue for an extended period of time depending on the specific site requirements. Some expenditure can continue into perpetuity. In such cases, the provision for these ongoing costs may be restricted to a period for which the costs can be reliably estimated.

On the date of initial recognition of the liability that arises from this obligation, discounted to present value using a risk free rate, the same amount is simultaneously charged to property, plant and equipment in the balance sheet. The selection of appropriate sources on which to base the calculation of the risk-free discount rate used for such retirement, restoration and environmental obligations requires judgment. Subsequently, the liability is increased in each period to reflect the finance cost considered in the initial measurement of the discount. Additionally, the capitalized cost is depreciated based on the useful life of the related asset. Upon settlement of the liability, the Group entities recognize any profit or loss that may arise.

Any reduction in this provision and, therefore, any reduction in the related asset, exceeding the carrying amount of the asset, are immediately recognized in the income statement as “operating costs”.

As a result of all of the above factors, there could be significant adjustments to the provision for close-down, restoration and environmental costs which would affect future financial results.

Judicial deposits

Judicial deposits are presented on a net basis in “Provisions” when there is a corresponding provision. The deposits without corresponding provisions are presented in non-current assets.

Critical accounting estimates and judgments

(i)Asset retirement obligations

The Company recognizes an obligation based on the fair value of the operations of asset retirement in the period in which the obligation occurs with a corresponding entry to the respective property, plant and equipment. The Company considers the accounting estimates related to the recovery of degraded areas and the costs to close a mine as critical accounting estimates since it involves a provision of significant amounts, and these estimates involve several assumptions such as interest rates, inflation, useful lives of the assets, costs to be incurred in the future and the dates established for the life of each mine. These estimates are reviewed annually by the Company.

(ii)            Tax, civil, labor and environmental provisions

The Company’s subsidiaries are parties to ongoing labor, civil, tax and environmental lawsuits which are pending at different court levels. The provisions for potentially unfavorable outcomes of litigation in progress are established and updated based on management evaluation, as supported by the positions of external legal counsel, and require a high level of judgment regarding the matters involved.

(a)Analysis

	2017														2016
					Judicial provision
	Asset Retirement Obligation (i)		Environmental Obligation (i)		Tax (ii)		Labor		Civil		Environmental		Total		Total
Balance at the beginning of the year	159,117		80,016		26,299		11,773		15,415		4,259		296,879		197,359
Present value adjustment	846		3,808										4,654		2,617
Additions	4,303		16,843		4,503		11,765		5,832		4,570		47,816		104,749
Reversals	—		(13,176	)	(14,569	)	(10,359	)	(63	)	(3,852	)	(42,019	)	(11,794	)
Judicial deposits, net of write-off	—		—		695		3,358		(778	)	—		3,275		(6,530	)
Write-off	(5,068	)	(3,847	)	(2,932	)	(3,703	)	(2,508	)	(608	)	(18,666	)	(7,678	)
Interest and indexation	—		—		4,429		3,818		341		234		8,822		4,926
Exchange variation	(2,520	)	191		150		(231	)	81		(38	)	(2,367	)	16,416
Companies excluded from the consolidation	(1,022	)	—		—		—		—		—		(1,022	)	—
Cost and interest revision	43,789		—		—		—		—		—		43,789		(3,186	)
Balance at the end of the year	199,445		83,835		18,575		16,421		18,320		4,565		341,161		296,879
Current	—		14,641		—		—		—		—		14,641		—
Non-current	199,445		69,194		18,575		16,421		18,320		4,565		326,520		296,879
	199,445		83,835		18,575		16,421		18,320		4,565		341,161		296,879

(i) In 2017, the Company conducted an update of its asset retirement obligations and potential environmental obligations. As a result of this study, which included the review of the timing of estimated disbursements, the Company recorded for Brazilian operations an additional asset retirement obligations in the amount of US$ 43,789, (US$ 38,541 related to cost revision and US$ 5,248 related to interest revision), and additional environmental obligations of US$ 16,843. For the new operation in Ambrosia, the Company recorded asset retirement obligations in the amount of US$ 4,227.

(ii) The reversal of the tax provision in the amount of US$ 14,569 during the year ended December 31, 2017 relates to a favorable judicial pronouncement for the exclusion of ICMS (tax levied over the sale of goods) from the calculation basis of PIS and COFINS (taxes levied over revenues).

(b)Asset retirement obligations

As these are long term obligations, they are revised periodically for inflation and discounted to their present value, using nominal interest rates. The liability recognized is adjusted periodically based on these rates and revised for inflation.

At December 31, 2017, the interest rate forecast for Peru was between 1.47% to 2.45% (2016: 0.50% to 2.45%) and for Brazil was 7.83% (2016: 8.47%).

The increase of 1% in the interest rate would reduce the liability related to Peruvian operations by US$ 1,235 and would reduce the liability related to Brazilian operations by US$ 7,996, totaling a reduction of US$ 8,131. The decrease of 1% in the interest rate would increase the liability related to Peruvian operations by US$ 564 and would increase the liability related to Brazilian operations in US$ 8,961, totaling a reduction of US$ 9,525.

(c)Tax, civil, labor and environmental provisions

The Company’s subsidiaries are parties to tax, civil, labor and environmental ongoing lawsuits and are contesting these matters at both at the administrative and judicial levels, backed by judicial deposits, when applicable.

The amounts of contingencies are periodically estimated and updated. The classification of losses as probable, possible or remote is supported by the advice of the Company’s legal counsel.

The provisions and the corresponding judicial deposits are as follow:

	2017					2016
	Judicial deposits		Provision	Net amount	Outstanding judicial deposits (i)	Judicial deposits		Provision	Net amount	Outstanding judicial deposits (i)
Tax	(2,318	)	20,893	18,575	3,130	(2,232	)	28,531	26,299	5,158
Labor	(4,765	)	21,186	16,421	7,408	(8,116	)	19,889	11,773	8,994
Civil	(758	)	19,078	18,320	23	(3	)	15,418	15,415	8
Environmental	—		4,565	4,565	388	—		4,259	4,259	—
	(7,841	)	65,722	57,881	10,949	(10,351	)	68,097	57,746	14,160

(i) The Company’s subsidiaries have deposited with the courts the above amounts in relation to proceedings classified by the Company, supported by its legal advisors as having a possible or remote possibility of loss, and which therefore, are not subject to provisions.

(d)Comments on provision with likelihood of loss considered probable

(i)            Provision for tax contingencies

Refers to the tax proceedings, with a probable likelihood of loss relating to federal, state and municipal taxes.

(ii)           Provision for civil contingencies

The Company’s subsidiaries are parties to civil lawsuits involving claims for compensation for property damage and pain and suffering.

(iii)          Labor lawsuits

The Company’s subsidiaries are parties to labor lawsuits filed by former employees, third parties and labor unions mostly claiming the payment of indemnities on dismissals, health hazard premiums and hazardous duty premiums, overtime, and commuting hours, as well as indemnity claims by former employees and third parties based on alleged occupational illnesses, work accidents, property and personal damage, in ordinary courts under Constitutional Amendment 45 and normative clauses. Our main court is in Minas Gerais — Brazil.

(iv)          Provisions for environmental contingencies

The Company and its subsidiaries are subject to laws and regulations in the various countries in which they operate. The Company has established policies and procedures to comply with environmental laws.

The Company performs analyses on a regular basis to identify environmental legal risks so as to ensure that the systems in place are adequate to manage these risks.

Moreover, the environmental litigation of the Company and its subsidiaries consists basically of civil public actions to interrupt the environmental licensing for manufacturing units and indemnity actions for alleged environmental impacts arising from the Company’s activities.

(e)Litigation with likelihood of loss considered possible

The Company’s subsidiaries are parties to other litigation involving a risk of possible loss, for which no provision is recorded, as detailed below:

	2017	2016
Tax	125,438	94,076
Labor	46,402	55,278
Civil	24,911	28,185
Environmental	133,851	130,549
	330,602	308,088

(e.1)Comments on contingent tax liabilities with likelihood of loss considered possible

The main contingent liabilities relating to tax lawsuits in progress with a likelihood of loss considered possible, for which no provision was recorded, are discussed below.

(i)Compensation for exploration for mineral resources

The subsidiary NEXA BR has had various tax assessment notices issued by the National Department of Mineral Production for alleged failure to pay or underpayment of Financial Compensation for the Exploration of Mineral Resources (CFEM). At December 31, 2017, the amount under litigation totaled US$ 8,799, considered a possible loss.

Currently, the lawsuits are at the administrative or judicial levels.

In the opinion of management and independent legal advisors, the procedure adopted by the Company is in conformity with the legislation and, for this reason, it is not considered probable that the Company will lose these lawsuits.

(ii)Tax assessment notice - Disallowance of ICMS credits arising from the acquisition of property, plant and equipment

In October 2011, in December 2013 and in January 2015, the subsidiary NEXA BR was assessed by the Secretary of Finance of the State of Minas Gerais concerning ICMS credits arising from the acquisition of property, plant and equipment allegedly not connected with the Company’s activities.

The administrative process ended in December 2016 with a partially favorable decision. This tax assessment notice amounted to US$ 10,273 at December 31, 2017.

In the opinion of management and independent legal advisors, it is considered possible that the subsidiary NEXA BR will lose the judicial proceeding.

(iii)Tax assessment notice — Disallowance of PIS credits

In May 2014, the subsidiary NEXA BR was assessed by the Brazilian Internal Revenue Service concerning PIS credits. This tax assessment notice amounted to US$ 8,143 at December 31, 2017. Currently the proceedings are at the administrative level.

In the opinion of management and the independent legal advisors, it is considered possible that the subsidiary NEXA BR will lose the administrative proceeding.

(iv)Tax assessment — Income taxes and social contribution

In October 2011, the subsidiary NEXA BR was assessed by the Brazilian Internal Revenue Service concerning IRPJ and CSLL related to the compensation of tax losses. This tax assessment notice amounted to US$ 5,891 at December 31, 2017. Currently the process is at the administrative level.

In the opinion of management and the independent legal advisors, it is considered possible that the subsidiary NEXA BR will lose the administrative proceeding.

(v)Tax assessment notice — Disallowance of COFINS credits

In November 2007, the subsidiary NEXA BR was assessed by the Brazilian Internal Revenue Service concerning COFINS credits. This tax assessment notice amounted to US$ 5,534 at December 31, 2017. Currently the lawsuit is at the judicial level.

In the opinion of management and the independent legal advisors, it is considered possible that the subsidiary NEXA BR will lose the judicial proceeding.

(vi)Requirement of Value-added Tax on Sales and Services (ICMS) on Energy

In December 2016, the subsidiary NEXA BR received a collection notice for alleged ICMS debts on the energy. This tax assessment notice amounted to US$ 5,236 at December 31, 2017. Currently the process is at the administrative level.

In the opinion of management and the independent legal advisors, it is considered possible that the subsidiary NEXA BR will lose the administrative proceeding.

(vii)Requirement of Value-added Tax on Sales and Services (ICMS)

In November 2017, the subsidiary NEXA BR was assessed by the Secretary of Finance of the State of Minas Gerais concerning ICMS tax rate of 4% applied in interstate sales of manufactured goods with imported content of more than 40%. This tax assessment notice amounted to US$ 9,842 at December 31, 2017. Currently the process is at the administrative level.

In the opinion of management and the independent legal advisors, it is considered possible that the subsidiary NEXA BR will lose the administrative proceeding.

(e.2)Comments on contingent labor liabilities with likelihood of loss considered possible

Labor claims with a likelihood of loss considered possible include those filed by former employees, third parties and labor unions, mostly claiming the payment of indemnities on dismissals, health hazard premiums and hazardous duty premiums, overtime and commuting hours, as well as indemnity claims by former employees and third parties based on alleged occupational illnesses and work accidents.

(e.3)Comments on contingent civil liabilities with likelihood of loss considered possible

The Company has two contingent civil liabilities with a likelihood of loss considered possible:

Indemnity lawsuits have been filed against the subsidiary NEXA BR, alleging property damage and pain and suffering. NEXA BR filed its defense and it is awaiting judgment. The amount involved at December 31, 2017 was US$ 11,690.

A claim relating to an alleged default of NEXA BR (construction owner) related to the services provided for the construction of a tailings dam in the Juiz de Fora unit, also claiming: (i) the execution of extra-contractual services performed beyond the initial scope of the project, (ii) reimbursement of the costs incurred to accelerate the work and, finally, (iii) financial losses that allegedly arose due to NEXA BR’s default on the contract, which were never pointed out by the Plaintiff during the business relationship (or during the contract execution). Currently, a court expert investigation is underway. The amount involved at December 31, 2017 was US$ 2,016.

(e.4)Comments on contingent environmental liabilities with likelihood of loss considered possible

The environmental litigation of the Company’s subsidiaries basically relate to public civil actions, class actions and indemnity lawsuits, whose objectives are: the suspension of the environmental licensing, the recovery of areas of permanent preservation, and the decontamination of land, among other matters. In the event of an unfavorable outcome, the cost of the preparation of environmental studies and the cost of the recovery of the Company’s and its subsidiaries’ land have been estimated. The aforementioned costs are recorded as expenses in the income statement as they are incurred. The possible demands relate basically to indemnity lawsuits. The Company’s subsidiaries filed their defenses, fully contesting the plaintiffs’ allegations. Most environmental lawsuits with material amounts and classified as possible are in the fact-finding phase.

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Use of public assets

12 Months Ended

Dec. 31, 2017

Use of public assets.

Use of public assets

22Use of public assets

Accounting policy

Use of public assets refers to the rights granted by the government to operate potential hydraulic energy (onerous concession), under an agreement for the Use of Public Assets.

The amount is recognized once the operating license is obtained, regardless of the payment schedule established in the contract. The amount is originally recognized as a liability (obligation) and an intangible asset (concession right) which corresponds to the amount of the future obligations discounted to the present value of the future payment cash flow. The financial liability is updated based on the contractual index and the present value adjustment resulting from the lapse of time and reduced by the payments made.

(a)Analysis

The Company owned or invested in plants that have concession contracts in the electrical power industry. Most of these contracts provide for annual payments from the commencement of operations and are adjusted by the General Market Price Index for the Use of Public Assets.

The contracts have an average duration of 35 years, and the amounts paid annually are as follows:

				2017				2016
Plants	Concession start date	Concession end date	Payment start date	Ownership interest		Intangible asset	Liabilities	Ownership interest		Intangible asset	Liabilities
Capim Branco I and Capim Branco II	Aug-01	Sep-39	Oct-07	13	%	800	3,085	13	%	890	3,357
Picada	May-01	Jun-36	Jul-06	100	%	5,502	19,535	100	%	5,856	20,776
Enercan - Campos Novos Energia	Apr-00	May-35	Jun-06	21	%	630	1,689	21	%	676	1,787
						6,932	24,309			7,422	25,920
Current							1,649				1,663
Non-current						6,932	22,660			7,422	24,257
						6,932	24,309			7,422	25,920

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Deferred revenue

12 Months Ended

Dec. 31, 2017

Deferred revenue

Deferred revenue

23Deferred revenue

In 2016, NEXA, through its subsidiary NEXA UK, conducted a transaction called “silver streaming”, which consists of the anticipated sale of the referential content of the silver that is incorporated in the ore concentrates.

In this context, on December 20, 2016, NEXA UK signed an agreement with Triple Flag Mining Finance Bermuda Ltda. (“Triple Flag”) by which NEXA UK sells to Triple Flag silver certificates in an amount equivalent to 65% of the silver content in the ore concentrate sold by the Company to its customers.  Sales taken as reference are those associated exclusively with the ore extracted from the Cerro Lindo Mining Unit, located in Peru, with silver content.

In addition, by this agreement, sales of silver certificates to Triple Flag are limited to a total of 19,500 of the ounces that the Company sells to its customers. Once that limit is reached, sales under the stream will be made for 25% of the silver content in the Company’s sales of concentrate for a period equivalent to the life of said mining unit.

As consideration, Triple Flag makes the following payments: i) an advance payment of US$ 250,000 which will not be reimbursed; and ii) additional payments at the date of delivery of the ounces of silver payable equivalent to 10% of the spot silver price at the date of settlement.

The resources obtained from the referred transaction are intended to be used in current operations and the potential development of NEXA’s projects.

The prepayment for US$ 250,000 received on December 21, 2016 was recorded in this item and is recognized as revenue together with the additional payments as the silver certificates are delivered to Triple Flag.  The Group delivers the certificates as the silver contents of its concentrate sales are collected from its customers that buy ore concentrates.

For the period ended December 31, 2017, NEXA UK delivered ore (silver certificates) to Triple Flag in accordance with the terms of the silver streaming agreement for a total of 2,372,983 ounces. As a result, the consolidated statement of income showed revenue from this transaction for US$ 36,299. The movements in the deferred income arising from this transaction are shown below:

At January 2017	250,000
Revenue recognition for ore delivery	(36,299	)
Accretion for period	8,184
At December 2017	221,885
Current	31,296
Non-current	190,589
	221,885

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Equity

12 Months Ended

Dec. 31, 2017

Equity.

Equity

24Equity

(a)Accounting policy

Common shares are classified in equity. Each time a share premium is paid to the Company for an issued share, the respective share premium is allocated to the share premium reserve account.

Each time the repayment of a share premium is decided, such repayment shall be done pro-rata to the existing shareholders.

The distribution of dividends to the Company’s shareholders is recognized as a liability in the Company’s consolidated financial statements in the period in which the dividends are approved by the Company’s shareholders.

(b)Capital

At December 31, 2017, the Company’s fully subscribed and paid-up capital, in the amount of US$ 133,320 (2016: US$ 1,041,416), comprised 133,320 thousand (2016: 1,041,416 thousand) registered common shares.

(c)Share premium

The share premium, if any, may be freely distributed to the shareholders in accordance with the law by a resolution of the Board of Directors. The constitution and payment of share premium during 2017 are demonstrated in notes 1 (iv), 1 (v) and 1 (x). At December 31, 2017, share premium account is in the amount of US$ 1,123,755.

(d)Reserves

The reserves were created to preserve the undistributed balance of retained earnings to fund expansion projects pursuant to the Company’s investment plan.

(e)Accumulated other comprehensive income (loss)

The Company recognizes in other comprehensive income (loss) the effects of foreign exchange gains/losses on direct and indirect investments abroad.

This account also includes: fair value gains/losses on derivatives designated to mitigate risks related to foreign exchange, commodity prices and interest rates (hedge accounting), and actuarial gains and losses on pension plans.

The changes in the accumulated other comprehensive income (loss) are as follows:

	Exchange
	variation on		Remeasurements with		Hedge
	investm ents abroad		retirement benefits		accounting		Total
At January 1, 2015	(45,297	)	2,792		444		(109,857	)
Currency translation of investees located abroad	(74,163	)	—		—		(74,163	)
Remeasurements of retirement benefits	—		535		—		535
Operating cash flow hedge accounting	—		—		5,832		5,832
At December 31, 2015	(119,460	)	3,327		6,276		(177,653	)
Currency translation of investees located abroad	30,373		—		—		30,373
Operating cash flow hedge accounting	—		—		(16,256	)	(16,256	)
At December 31, 2016	(89,087	)	3,327		(9,980	)	(163,536	)
Currency translation of investees located abroad	(10,742	)	—		—		(10,742	)
Operating cash flow hedge accounting	—		—		12,556		12,556
Achievement of remeasurements with retirement benefits	—		(3,327	)	—		(3,327	)
At December 31, 2017	(99,829	)	—		2,576		(165,049	)

(f)Earnings per share

Basic and diluted earnings per share were computed as shown in the table below for the periods indicated. Basic earnings per share are computed by dividing the profit (loss) attributable to owners of the parent by the average number of shares for the period. Diluted earnings per share are computed on a similar way, but with the adjustment in the denominator when assuming the conversion of all shares that may be diluted.

(i)Basic

Earnings per share information have been retroactively adjusted for proportional reductions in the number of shares arising from transfers from Capital to Share Premium, which resulted in the effects bellow:

· Cancellation of 350,000,000 shares in April 2016;

· Cancellation of 200,000,000 shares in June 2017,

· Cancellation of 300,000,000 shares in September 2017 and

· Cancellation of 428,595,552 shares in October 2017.

		(Restated)	(Restated)
	2017	2016	2015
Profit (loss) attributable to owners of the parent	126,885	93,167	(129,461	)
Weighted average number of outstanding common shares (thousands)	116,527	80,699	1,874
Earnings per share in US Dollars	1.09	1.15	(69.08	)

(ii)Diluted

As of December 31. 2017, the Company does not have any instrument with potential dilutive effect, therefore basic and dilute earnings per share are the same.

(g)Non-controlling interests

	NEXA CJM (i)		Pollarix S.A. (ii)
Summarised balance sheet	2017	2016	2017	2016
Current assets	1,105,182	1,159,112	6,717	26,128
Current liabilities	469,291	462,428	911	12,667
Current net assets	635,891	696,684	5,806	13,461
Non-current assets	2,852,410	3,070,147	110,246	161,595
Non-current liabilities	987,143	1,107,542	24,978	39,184
Non-current net assets	1,865,267	1,962,605	85,268	122,411
Net assets	2,501,158	2,659,289	91,074	135,872
Accumulated NCI	361,265	385,762	60,716	90,581

(i) Consolidated amounts, which includes NEXA CJM, NEXA PERU and NEXA ATACOCHA.

(ii) Consolidated amounts, which includes the energy generation assets Enercan, Capim Branco, Igarapava and Picada.

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Net revenue

12 Months Ended

Dec. 31, 2017

Net revenue

Net revenue

25Net revenue

Accounting policy

Revenue represents the fair value of the consideration received or receivable for the sale of goods in the ordinary course of the Company’s activities. Revenue is shown net of value-added tax, returns, rebates and discounts, after eliminating sales between the consolidated companies.

The Company recognizes revenue when: (i) the amount of revenue can be reliably measured; (ii) it is probable that future economic benefits will flow to the entity; and (iii) specific criteria have been met for each of the Company’s activities as described below. Revenue will not be deemed to be reliably measured if all sale conditions are not resolved. The Company bases its estimates on historical results, taking into consideration the type of customer, the type of transaction and the specifics of each arrangement.

Revenue recognition is based on the following principles:

Sale of goods: Sales are normally recognized when the goods are delivered to the carrier and the ownership and risks with respect thereto are transferred to the customer.

Revenue from sales of concentrates is determined based on the prices of international quotes and in accordance with the contractual terms. In such cases, revenue is initially recognized at a provisional price which corresponds to the international quoted price at the shipping date. The amount of the provision for settlement is adjusted to reflect future prices, according to international quotes at the closing date of each month, until a final adjustment is carried out to value the sales in accordance with the prices agreed upon with customers, based on the contractual sales terms. The adjustments of provisional settlements are recognized in trade accounts receivable, against sales revenue when:

· The future price, mentioned above, for shipment or delivery, for a determined period (pre-final) settlement, or at the close of an accounting period is different to the price recorded.

· A debit or credit note is issued after the adjustments of the provision for settlement are recognized, based on the final weights or final contents, which results in a higher or lower amount, respectively, compared to the amount of the provision for settlement.

A debit or credit note is issued when the final price has been defined.

(a)Composition of net revenue

	2017		(Revised) 2016		(Revised) 2015
Gross revenue	2,709,236		2,193,867		2,072,439
Taxes on sales and returns	(259,752	)	(229,026	)	(207,256	)
Net revenue	2,449,484		1,964,841		1,865,183

(b)Information on geographical areas in which the Company operates

The geographical areas are determined based on the location of the customers. The net revenue of the Company, classified by currency and destination, is as follows:

(i)Revenue by destination

	2017	(Revised) 2016	(Revised) 2015
Brazil	721,640	560,878	534,141
Peru	696,527	573,884	584,450
United States	158,060	156,634	99,884
Luxembourg	130,723	100,631	98,159
Switzerland	108,798	59,873	135,450
Argentina	79,463	45,050	14,904
Japan	69,565	36,005	32,994
Singapore	60,857	42,666	72,514
Colombia	47,734	39,137	42,007
Chile	38,101	67,546	52,865
Austria	37,270	22,982	18,731
Turkey	35,522	19,498	23,265
Germany	23,154	42,560	22,348
China	18,172	12,838	639
Italy	15,799	3,608	1,399
Korea	7,064	66,887	51,181
Other	201,035	114,164	80,252
	2,449,484	1,964,841	1,865,183

(ii)Revenue by currency

	2017	(Revised) 2016	(Revised) 2015
US Dollar	1,729,234	1,414,992	1,334,878
Real	717,032	547,537	529,218
Other	3,218	2,312	1,087
	2,449,484	1,964,841	1,865,183

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Expenses by nature

12 Months Ended

Dec. 31, 2017

Expenses by nature

Expenses by nature

26Expenses by nature

(a)Composition

	2017	(Revised) 2016	(Revised) 2015
Raw materials and consumables used	1,120,540	956,909	980,533
Employee benefit expenses	278,285	233,755	202,876
Depreciation and amortization	270,454	275,034	295,258
Freight costs	75,674	68,962	73,871
Services, miscellaneous	156,491	89,426	77,772
Other expenses	17,239	32,967	23,838
	1,918,683	1,657,053	1,654,148
Reconciliation
Cost of products sold	1,681,202	1,439,101	1,463,290
Selling expenses	89,239	90,647	84,559
General and administrative expenses	148,242	127,305	106,299
	1,918,683	1,657,053	1,654,148

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Employee benefit expenses

12 Months Ended

Dec. 31, 2017

Employee benefit expenses

Employee benefit expenses

27Employee benefit expenses

Accounting policy

(i)Profit sharing

A provision is recorded to recognize the expenses related to employee profit sharing. This provision is calculated based on the qualitative and quantitative targets established by management and are recorded as “Employee benefits” in the income statement.

(ii)Share-based payments

The subsidiary NEXA PERU operates a cash-settled, share-based compensation plan, under which the company gives certain executives a package of equity instruments (options) as consideration for services received, which is based on the value of equity instruments (“Phantom options”) of the NEXA PERU.

The cost of the cash settled share-based payments plan is initially measured at fair value as at the grant date using the Black-Scholes financial model. This fair value is accrued over the period until the vesting date, with the recognition of the liability. The liability is measured again at fair value at each reporting date, and it is reported up to and including the settlement date, with changes in fair values recognized as expenses of employee benefits in the income statement.

The purpose of such incentive plan is to align a portion of the compensation of the company’s senior executives with the evolution of the NEXA PERU’s market value.

(a)Analysis

	2017	2016	2015
Direct remuneration	146,766	126,570	112,072
Social charges	76,677	66,863	60,761
Benefits	54,842	40,322	30,043
	278,285	233,755	202,876

For the year ended December 31, 2017, the average staff headcount was 5,643 (2016: 5,561).

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Other operating expenses, net

12 Months Ended

Dec. 31, 2017

Other operating expenses, net

Other operating expenses, net

28Other operating expenses, net

	2017		2016		2015
Environmental and asset retirement obligations	433		(68,605	)	—
Mining obligations	(11,498	)	(8,967	)	(8,953	)
Project expenses	(94,280	)	(48,562	)	(37,623	)
Net operating hedge loss	(18,785	)	(33,514	)	7,045
Judicial (provision) reversion	258		(15,331	)	—
Loss on sale of property, plant & equipment and intangibles assets	(694	)	(552	)	(3,446	)
Gain on sale of investment	4,588		408		—
Impairment of property, plant, equipment and intangibles	—		979		(8,574	)
Other operating expenses, net	(9,243	)	(3,675	)	4,446
	(129,221	)	(177,819	)	(47,105	)

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Net financial results

12 Months Ended

Dec. 31, 2017

Net financial results

Net financial results

29Net financial results

	2017		2016		2015
Finance income
Gains on financial investments	21,388		12,032		9,132
Interest on loans with related parties (Note 13)	1,012		7,165		5,702
Monetary adjustment of assets	1,881		1,507		1,147
Interest on financial assets	2,621		2,921		1,387
Other finance income	2,966		1,330		1,900
	29,868		24,955		19,268
Finance costs
Interest on loans and financing	(56,434	)	(36,059	)	(33,073	)
Interest on deferred revenue	(8,184	)	—		—
Monetary adjustment of provisions	(9,478	)	(9,595	)	(5,966	)
Charges on discounting of trade bills	(5,379	)	(6,105	)	(4,524	)
Present value adjustment	(9,180	)	(4,291	)	(3,341	)
Other finance costs	(17,514	)	(14,324	)	(14,721	)
	(106,169	)	(70,374	)	(61,625	)
Exchange and monetary variations, net (i)	(53,880	)	124,500		(299,574	)
Finance results, net	(130,181	)	79,081		(341,931	)

(i) Exchange variation is related mainly to debt of NEXA BR denominated in U.S. Dollar.

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Information by business segment and geographic area

12 Months Ended

Dec. 31, 2017

Information by business segment and geographic area

Information by business segment and geographic area

30Information by business segment and geographic area

Accounting policy

The internal body, which makes decisions regarding the relevant activities of the Company, is comprised of the Executive Officers who report directly to the Chief Executive Officer (“CEO”) who analyzes the results of NEXA and has the final authority over resource allocation decisions and performance assessment over mining and smelting segments. This assessment is based on the fact that NEXA considers that the different mining and smelting units can be combined in its own specific segment due to the fact that they present similar financial performances, similar types of products, productive process and types of clients and regulatory framework.

The internal information used for making decisions is prepared applying accounting measurement bases with managerial adjustments. The sales information is broken down by product, geographical origin location and geographical customer location. The non-current assets are presented by location.

(a)Business segment

Nexa implemented several decisions to reinforce the strategic positioning in two core business segments - Mining and Smelting. The reportable segments are aligned according to the product type and operation.

The Mining division consists of five operating units located in Brazil and Peru and includes mineral exploration activities and the production of zinc concentrates, copper concentrates and lead concentrates, where due to concentrate benchmark pricing criteria, revenues from the mining business can also be inferred in terms of the contents of zinc, copper, lead, silver and gold. Our mining operations in Peru are conducted by our subsidiary NEXA PERU and in Brazil by our subsidiary NEXA BR.

The Smelting division consists of three operating units also located in Brazil and Peru that include facilities that recover and refine zinc metal out of feed materials such as zinc concentrates or secondary feed materials. In this process, the segment produces metallic zinc (SHG zinc and zinc alloys), zinc oxide and by-products, such as sulfuric acid. Smelting operations in Peru are conducted by our subsidiary NEXA CJM and in Brazil by our subsidiary NEXA BR.

NEXA also has a corporate headquarters, which is not a separate operating unit and is not considered as a business segment, but is included in our reconciliation allocated in the reportable segments.

Each of the two segments has a specific Officer who reports directly to the CEO. The CEO has final authority over resource allocation decisions and performance assessment. Consequently, the CEO has been identified as the chief operational decision maker (CODM).

The CODM monitors the operational results of the business segments separately, in order to be able to make decisions on resources allocation and to performance assessment. Segment performance is measured based on adjusted EBITDA year to date, which may be measured differently from the EBITDA presented in note 5.2. Financial results and taxes on income are managed within the corporate level and are not allocated to operating segments.

For financial information, segments are reported on a statutory basis in accordance with IFRS 8 ‘Operating Segments’, and the information presented to the Board of Directors (“Directors”) and CEO on the performance of each segment is derived from the accounting records, adjusted for reallocations between segments, non-recurring effects, transfer pricing adjustments, extraordinary revenues or expenses not allocated in a specific segment.

For NEXA BR results from operations reflect that zinc concentrates produced in the Vazante and Morro Agudo mines in Brazil are transferred at cost to the Três Marias smelter. As a result, zinc concentrates production from our Vazante and Morro Agudo mines has its margin embedded on Três Marias smelter. In order to evaluate the performance of our mining and smelting segment, the Company prepares an internal calculation based on transfer-pricing adjustments according to arm’s length principle basis and benchmark.

(b)Revenue

The Mining Segment recognized in 2017 total amount of US$ 273,409 (2016: US$ 161,676 and 2015: US$ 125,912) related to transfer-pricing adjustment and US$ 448,054 (2016: US$276,562 and 2015: US$ 225,129) related to intersegment elimination, totaled in the elimination column.

	2017
	Mining		Smelting		Elimination		Adjustment(i)		Total
Revenue from external customers	491,758		1,952,006		—		5,719		2,449,484
Intersegment (sales or transfer)	721,463		—		(721,463	)	—		—
Net revenue from products sold	1,213,221		1,952,006		(721,463	)	5,719		2,449,484
Cost of products sold	(581,029	)	(1,698,325	)	721,463		(123,311	)	(1,681,202	)
Gross Profit	632,192		253,681		—		(117,592	)	768,282

	(Revised) 2016
	Mining		Smelting		Elimination		Adjustment(i)		Total
Revenue from external customers	469,187		1,491,988		—		3,666		1,964,841
Intersegment (sales or transfer)	438,238		—		(438,238	)	—		—
Net revenue from products sold	907,425		1,491,988		(438,238	)	3,666		1,964,841
Cost of products sold	(513,135	)	(1,260,519	)	438,238		(103,685	)	(1,439,101	)
Gross Profit	394,290		231,469		—		(100,019	)	525,740

	(Revised) 2015
	Mining		Smelting		Elimination		Adjustment(i)		Total
Revenue from external customers	420,663		1,421,307		—		23,213		1,865,183
Intersegment (sales or transfer)	350,041		—		(350,041	)	—		—
Net revenue from products sold	770,704		1,421,307		(350,041	)	23,213		1,865,183
Cost of products sold	(532,097	)	(1,170,545	)	350,041		(110,689	)	(1,463,290	)
Gross Profit	238,607		250,762		—		(87,476	)	401,893

(i) The column “Adjustment” represents the residual component of revenue from external customers and cost of products sold either not pertaining to the Mining or Smelting segments, or, represents items that, because of their nature, are not being allocated to a specific segment, such as revenues sales of concentrate executed from the smelting segment, purchase price allocation amortization of the fair value adjustments which were recognized upon the acquisition of NEXA PERU, and other variable payments related to production performance results, fair value hedge from other operating expenses.

The table below shows the composition of the revenue from external customer adjustments according to their nature:

	2017		2016		2015
Sales of concentrate from smelting segment	5,740		7,153		17,945
VMZ Energy sales	—		—		8,354
Other	(21	)	(3,487	)	(3,086	)
Total Adjustment on revenue from external customer	5,719		3,666		23,213

The table below shows the composition of the cost of products sold adjustments according to their nature:

	2017		2016		2015
Cost of concentrate sold by smelting segment	(3,303	)	(2,405	)	(10,968	)
Cost of energy sold by VMZ	—		—		(4,788	)
Employee compensation - Production performance	(33,969	)	(31,602	)	(21,825	)
Amortization of purchase price allocation of Milpo	(77,585	)	(77,585	)	(77,672	)
Fair Value Hedge	(8,406	)	14,729		(6,230	)
Other	(48	)	(6,822	)	10,794
Total adjustment on cost of products sold	(123,311	)	(103,685	)	(110,689	)

(c)Segment adjusted EBITDA

The Directors and CEO evaluate the performance of the operating segments based on adjusted EBITDA. The presentation of Adjusted EBITDA and its reconciliation to net income are as follows:

	2017		2016		2015
Mining	521,544		336,796		221,791
Smelting	152,739		70,528		259,768
Segment Adjusted EBITDA	674,283		407,324		481,559
Extraordinary items:
Gains on sales of investments	4,588		408		—
Impairment of other assets	(73	)	(308	)	—
(Reversal) Impairment - property, plant, equipment	—		979		(8,574	)
Other (i)	(6,764	)	(3,400	)	(13,797	)
Results of investees	60		(158	)	(256	)
Depreciation, amortization and depletion	(270,454	)	(275,034	)	(295,258	)
Net financial results	(130,181	)	79,081		(341,931	)
Taxes on income	(106,194	)	(98,383	)	38,779
Descontinued operations	—		—		(318	)
Profit (loss) for the year	165,265		110,509		(139,796	)

(i) The line item “Other” represents the residual component of Adjusted EBITDA either not pertaining to the Mining or Smelting segments, or, represents items that, because of their nature, are not being allocated to a specific segment.

(d)Information by geographic area

NEXA has its operations located in Brazil and Peru with trading activities in Luxembourg and United States. Until December 2016, NEXA also had trading activities in Austria that were fully transferred to Luxembourg. The revenue by geographical areas is determined by the location of our customers and is presented in note 25 (i).

The following tables shows the Company’s net revenue and cost of products sold by origin of the Company products, considering the allocation of our trading entities revenues and costs to Brazil and Peru, as applicable, net of the elimination of intersegment operations between our subsidiaries.

	2017
	Net revenue from products sold	Cost of products sold		Gross profit
Brazil	1,003,804	(670,964	)	332,840
Peru	1,445,680	(1,010,238	)	435,442
Total	2,449,484	(1,681,202	)	768,282

	(Revised) 2016
	Net revenue from products sold	Cost of products sold		Gross profit
Brazil	727,462	(484,851	)	242,611
Peru	1,237,379	(954,250	)	283,129
Total	1,964,841	(1,439,101	)	525,740

	(Revised) 2015
	Net revenue from products sold	Cost of products sold		Gross profit
Brazil	665,573	(460,284	)	205,289
Peru	1,199,610	(1,003,006	)	196,604
Total	1,865,183	(1,463,290	)	401,893

On December 31, 2017 the total of property, plant and equipment and intangibles located in Brazil represents the total amount of US$ 1,025,291 (2016: US$ 851,465), in Peru represents the total amount of US$ 2,792,285 (2016: US$ 3,025,199). The total amount located in other countries is US$ 1,657 (2016: US$ 2,322).

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Defined contribution pension plans

12 Months Ended

Dec. 31, 2017

Defined contribution pension plans

Defined contribution pension plans

31Defined contribution pension plans

Accounting policy

The Company, through its subsidiaries abroad, participates in pension plans, managed by a private pension entity, which provide post-employment benefits to employees.

In Brazil, the Company sponsors a defined contribution plan. A defined contribution plan is a pension plan under which the Company pays fixed contributions to a separate entity. The Company has no legal or constructive obligations to make additional contributions should the fund not have sufficient assets to honor the benefits related to employee service in the current or prior periods.

In Peru, termination benefits are recognized in profit or loss when they are paid. This happens when employment is terminated before the normal retirement date or whenever an employee accepts voluntary redundancy in exchange for these benefits.

The employees’ severance indemnities for the length of service of the Company’s staff hired in Peru represent their indemnification rights, calculated in accordance with the laws and regulations in force, which have to be credited to the bank accounts designated by the workers in May and November of each year. The compensation for time of service is equivalent to one (1) additional month’s salary effective at the date of the bank deposit. The Company has no obligations to make any additional payments once the annual deposits to which workers are entitled have been made.

(a)Analysis

The Company sponsors private pension plans in Brazil administered by Fundação Senador José Ermírio de Moraes (“FUNSEJEM”), a private, not-for-profit, pension fund which is available to all employees. Under the fund regulations, the contributions from employees to FUNSEJEM are matched based on their remuneration. For employees with remuneration lower than the limits established by the regulations, contributions up to 1.5% of their monthly remuneration are matched. For employees with remuneration higher than the limits, contributions of employees up to 6% of their monthly remuneration are matched. Voluntary contributions can also be made to FUNSEJEM. After the contributions to the plan are made, no further payments are required from the Company.

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Insurance coverage

12 Months Ended

Dec. 31, 2017

Insurance coverage

Insurance coverage

32Insurance coverage

Pursuant to the Company’s Insurance Management Corporate Policy, different types of insurance policies are contracted, such as operational risk and civil liability insurance, to protect assets against production interruptions and against damages caused to third parties.

The Company and its subsidiaries have civil liability insurance for their operations in Brazil, Peru and Europe, for which the coverage and conditions are considered by the Company’s management to be appropriate for the risks involved.

For the main plants in Brazil and operations abroad, an “All Risks” policy is contracted for all assets, including coverage against losses resulting from production interruptions.

The operational insurance coverage as at December 31, 2017 was as follows:

Assets	Type of coverage	Insured amount
Facilities, equipment and	Property damage	3,234,169
products in inventory	Loss of profits	778,735

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Subsequent events

12 Months Ended

Dec. 31, 2017

Subsequent events

Subsequent events

33         Subsequent events

(i)         Reimbursement of share premium

On February 15, 2018, the Board of Directors approved the reimbursement of share premium of US$ 0.60 cents per ordinary share to shareholders of the Company of record at the close of business on March 14, 2018 and paid US$ 80,000 to its shareholders on March 28, 2018.

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Summary of significant accounting policies (Policies)

12 Months Ended

Dec. 31, 2017

Summary of significant accounting policies

Subsidiaries

Subsidiaries include all entities over which NEXA has direct or indirect control. NEXA controls an entity when it is exposed to, or has the right to, variable returns from its involvement with the entity and the Company has the ability to affect those returns through its power over the entity. Subsidiaries are fully consolidated from the date on which control is transferred to the Company, except when the predecessor basis of accounting is applied. Subsidiaries are deconsolidated from the date on which that control ceases.

Transactions, balances and unrealized gains and losses between Group companies are eliminated.

The accounting policies of subsidiaries are adjusted where necessary to ensure consistency with the policies adopted by the Company.

Business combinations

The acquisition method of accounting is used for transactions classified as business combinations. The consideration transferred for the acquisition of a subsidiary is the fair value of the assets transferred, the liabilities assumed and the equity instruments issued. The consideration transferred includes the fair value of assets or liabilities resulting from a contingent consideration arrangement, when applicable. Acquisition-related costs are expensed as they are incurred. Identifiable assets acquired and liabilities assumed in a business combination are measured initially at their fair values at the acquisition date. The Company recognizes any non-controlling interest in the acquiree on an acquisition-by-acquisition basis, either at fair value or at the non-controlling interest’s proportionate share of the fair value of the acquiree’s identifiable net assets. The non-controlling interests to be recognized are determined upon each acquisition.

The excess of the consideration transferred, amount of any non-controlling interest in the acquired entity, and the acquisition-date fair value of any previous equity interest in the acquired entity over the fair value of the net identifiable assets acquired is recorded as goodwill. If those amounts are less than the fair value of the net identifiable assets of the subsidiary acquired, the difference is recognized directly in profit or loss as a bargain purchase.

Business combinations does not consider common control transactions.

Foreign currency translation

(i)Functional and presentation currency

Items included in the consolidated financial statements of each of NEXA’s entities are measured using the currency of the primary economic environment in which the entity operates (the “functional currency”). The consolidated financial statements are presented in US Dollars (“US$”), which is NEXA’s functional and reporting currency.

(ii)Transactions and balances

Foreign currency transactions are translated into the functional currency using the exchange rates at the dates of the transactions. Foreign exchange gains and losses resulting from the settlement of such transactions and from the translation of monetary assets and liabilities denominated in foreign currencies at year end exchange rates are recognized in profit or loss. They are deferred in other comprehensive income if they relate to qualifying cash flow hedges.

Foreign exchange gains and losses that relate to cash and cash equivalents and borrowing are presented in the income statement, within finance income or expenses.

Non-monetary items that are measured at fair value in a foreign currency are translated using the exchange rates at the date when the fair value was determined. Translation differences on assets and liabilities carried at fair value are reported as part of the fair value gain or loss. For example, translation differences on non-monetary assets and liabilities such as equities held at fair value through profit or loss are recognized in profit or loss as part of the fair value gain or loss and translation differences on non-monetary assets such as equities classified as available-for-sale financial assets are recognized in other comprehensive income.

(iii)Group companies

The results and financial position of all of the Company’s entities (none of which has the currency of a hyper-inflationary economy) that have a functional currency different from the reporting currency are translated into the presentation currency as follows:

· Assets and liabilities for each balance sheet presented are translated at the closing rate at the date of that balance sheet;

· Income and expenses for each income statement, are translated at average exchange rates (unless this average is not a reasonable approximation of the cumulative effect of the rates prevailing on the transaction dates, in which case income and expenses are translated at the rates in force on the dates of the transactions); and

· All resulting exchange differences are recognized in other comprehensive income.

Transactions with non-controlling interests

The Company treats transactions with non-controlling interests that do not result in a loss of control as transactions with the equity owners of the Company. A change in ownership interest results in an adjustment between the carrying amounts of the controlling and non-controlling interests to reflect their relative interests in the subsidiaries. Any difference between the amount of the adjustment to non-controlling interests and any consideration paid or received is recognized in a separate reserve within equity attributable to the owners.

Derivatives

Derivatives are initially recognized at fair value as at the date on which a derivative contract is entered into and are subsequently measured again at fair value. The method of recognizing the resulting gain or loss depends on whether the derivative is designated as a hedging instrument, in the case of adoption of hedge accounting, and if so, the nature of the item being hedged. The Company adopts the hedge accounting procedure and designates certain derivatives as either:

· Hedges of the fair value of recognized assets or liabilities or a firm commitment (fair value hedge); or

· Hedges of a particular risk associated with a recognized asset or liability or a highly probable forecast transaction (cash flow hedge).

The Company documents at the inception of the hedging transaction the relationship between hedging instruments and hedged items, as well as its risk management objectives and strategy for undertaking various hedge transactions. The Company also documents its assessment, both at hedge inception and on an ongoing basis, of whether the derivatives that are used in hedging transactions have been, and will continue to be, highly effective in offsetting changes in the fair value or cash flow of hedged items.

The full fair value of a hedging derivative is classified as a non-current asset or liability when the remaining maturity of the hedged item is more than 12 months, and as a current asset or liability when the remaining maturity of the hedged item is less than 12 months.

(i)Cash flow hedge

To ensure a fixed operating margin for a part of its production, the Company contracts derivative financial instruments for the forward sale of each commodity (zinc, copper and silver), and for NEXA BR, which has Reais as its functional currency, derivative financial instruments also includes the forward sale of US Dollars. The Company adopts hedge accounting for derivative instruments contracted for hedging purposes. The effective portion of the changes in fair value of derivatives that are designated and qualify as cash flow hedges is recognized in equity, recorded in “Accumulated other comprehensive income (loss)”. Gains and losses related to the non-effective portion are immediately recognized as “Other operating expenses, net”. The amounts recognized in equity are taken to the income statement upon realization of the hedged exports and/or sales referenced to the LME price.

Amounts accumulated in shareholders’ equity are reclassified to profit or loss in the periods when the hedged item affects the profit or loss (for example, when the forecast sale that is being hedged takes place).  The gain or loss relating to the effective portion of interest rate swaps hedging variable rate borrowing is recognized in the income statement within “Net financial results”.

When a hedging instrument expires or is sold, or when a hedge no longer meets the criteria for hedge accounting, any cumulative gain or loss existing in equity at that time remains in equity and is recognized when the forecast transaction is ultimately recognized in the income statement. When a forecast transaction is no longer expected to occur, the cumulative gain or loss that was reported in equity is immediately transferred to the income statement within “Other operating expenses, net”.

(ii)Fair value hedge

The Group has entered into commodities prices forwards that are fair value hedges for LME fluctuation risk arising from its firm commitments for purchases and sales of such commodities. The Company adopts hedge accounting for derivative instruments contracted for hedging purposes. Changes in the fair values of derivatives that are designated and qualify as fair value hedges are recorded in “Other operating expenses, net”. The change in the fair value of the hedged item is also recorded in “Other operating expenses, net”.

(iii)Derivatives carried at fair value through profit or loss

Certain derivative instruments do not qualify for hedge accounting. Changes in the fair values of any of these derivative instruments are recognized immediately in the income statement within “Other operating expenses, net”. Instruments not qualifying as hedges that are intended to hedge fluctuations in interest rates are classified in “Net financial results”.

Financial instruments by category

Normal purchases and sales of financial assets are recognized on the trade date — the date on which the Company commits to purchase or sell the asset. Investments are initially recognized at fair value plus transaction costs for all financial assets not carried at fair value through profit or loss. Financial assets carried at fair value through profit or loss, if any, are initially recognized at fair value, and transaction costs are expensed in the income statement.

Financial assets are derecognized when the rights to receive cash flow from the investments have expired or the Company has transferred substantially all of the risks and rewards of ownership. Financial assets at fair value through profit or loss are subsequently carried at fair value. Loans and receivables are carried at amortized cost using the effective interest rate method.

Gains or losses arising from changes in the fair value of the financial assets held for trading are presented in the income statement under “Net financial results” in the year in which they arise.

The fair values of quoted investments are based on current market prices.  If the market for a financial asset is not active, the Company establishes the fair value using valuation techniques. These include the use of recent arm’s length transactions, reference to other instruments that are substantially the same, discounted cash flow analysis, and option pricing models making maximum use of market inputs and relying as little as possible on entity-specific inputs.

The Company and its subsidiaries classify their financial assets under the following categories: at fair value through profit or loss (held for trading), held to maturity and loans and receivables. The classification depends on the purpose for which the financial assets were acquired. Management determines the classification of its financial assets upon initial recognition.

(i)Financial assets at fair value through profit or loss

Financial assets at fair value through profit or loss are financial assets held for trading. A financial asset is classified in this category if it was acquired principally for the purpose of selling in the short term. The changes are recognized in the income statement for the year within “Net financial results”. All financial assets in this category are classified as current assets.

Derivatives are also categorized as held for trading, unless they are designated as hedges.

(ii)Held to maturity

Investments in non-derivative marketable securities made by the Company with the ability and intention of being held to maturity, are classified as held to maturity investments and recorded at amortized cost. The Company assesses, at the balance sheet date, whether there is objective evidence that a financial asset or group of financial assets is impaired. If such evidence exists, a provision for the impairment of the asset is recorded.

(iii)Loans and receivables

Loans and receivables are non-derivative financial assets with fixed or determinable payments that are not quoted in an active market.  They are included in current assets, except for those with maturities greater than 12 months after the end of the reporting period, which are classified as non-current assets. The Company’s loans and receivables are mainly comprised of “cash and cash equivalents” and “trade accounts receivable”.

Cash and cash equivalents

Cash and cash equivalents includes cash, bank deposits, and highly liquid short-term investments (investments with an original maturity less than 90 days), which are readily convertible into a known amount of cash and subject to an immaterial risk of changes in value and bank overdrafts. Bank overdrafts are shown within loans and financing in current liabilities in the balance sheet.

Trade accounts receivable

Trade accounts receivable are amounts due from customers for goods sold in the ordinary course of the Company’s business.

Trade accounts receivable are recognized initially at fair value and subsequently measured at amortized cost using the effective interest rate method, less a provision for uncollectible trade receivables. Trade accounts receivable from export sales are presented at the foreign exchange rates prevailing on the reporting date.

Credit risk can arise from non-performance by counterparties of their contractual obligations towards the Company. To ensure an effective evaluation of credit risk, management applies comprehensive procedures related to the application for credit granting and approvals, renewal of credit limits, continuous monitoring of credit exposure in relation to established limits and events that trigger requirements for secured payment terms. As part of the Company’s process, the credit exposures with all counterparties are regularly monitored and assessed on a timely basis.

The Company recognized provision for uncollectible trade receivables for notes overdue for more than 120 days, whose expectation of collection is unlikely, as well as for customers considered bankrupt or in judicial reorganization.

Inventory

Inventory is stated at the lower of cost and net realizable value. Cost is determined using the weighted average cost method. The cost of finished goods and work in progress comprises raw materials, direct labor, other direct costs and related production overheads (based on normal operating capacity). The net realizable value is the estimated selling price in the ordinary course of business, less any additional selling expenses.  Imports in transit are stated at the accumulated cost of each import.

The Company, at least once a year, counts its physical inventory of goods to ensure that the physical balances and the recorded balances are the same. Any adjustment to be performed is booked under “Cost of products sold”.

Property, plant and equipment

Property, plant and equipment are stated at the historical cost of acquisition or construction less accumulated depreciation. Historical cost includes expenditure that is directly attributable to the acquisition and construction of the qualifying assets.

Subsequent costs are included in the asset’s carrying amount, or recognized as a separate asset as appropriate, only when it is probable that future economic benefits associated with the item will flow to the Company and they can be measured reliably. The carrying amounts of the replaced items or parts are derecognized.

All other repairs and maintenance are charged to the income statement during the financial period in which they are incurred. The cost of major renovations is included in the carrying amount of the asset when it is probable that the Company will realize future economic benefits in excess of the original benchmark performance specifications of the existing asset. Renovations are depreciated over the remaining useful life of the related asset.

Land is not depreciated. Depreciation of other assets is calculated using the straight line method to reduce their costs to their residual values over their estimated useful lives.

The assets’ residual values and useful lives are reviewed, and adjusted if appropriate, at the end of each reporting period.

An asset’s carrying amount is written down immediately to the recoverable amount when it is greater than the estimated recoverable amount, in accordance with the criteria adopted by the Company in order to determine the recoverable amount.

Gains and losses on disposals are determined by comparing the proceeds with the carrying amount and are recognized within “Other operating expenses, net” in the income statement.

Leases

Leases in which a significant portion of the risks and rewards of ownership are retained by the lessor are classified as operating leases. Payments made under an operating lease (net of any incentive received from the lessor) are charged to the income statement on a straight line basis over the period of the lease.

The subsidiaries lease certain property, plant and equipment. Leases of property, plant and equipment, where the Company has substantially all the risks and rewards of ownership, are classified as finance leases. Finance leases are capitalized at the inception of the lease at the lower of the fair value of the leased item and the present value of the minimum lease payments.

Each lease payment is allocated between the liability and finance charges. The corresponding rental obligations, net of finance charges, are included in “Loans and financing”.

The interest element of the finance cost is charged to the income statement over the lease period so as to give a constant periodic rate of interest on the remaining balance of the liability for each period. The property, plant and equipment acquired under finance leases are depreciated over the shorter of the asset’s useful life and the lease term.

Impairment of non-financial assets

The Company assesses, at each reporting date, whether there is an indicator that an asset or cash generating unit (“CGU”) may be impaired. If any indication exists, such as volumes and prices reductions or unusual events that can affect the business for example, the Company estimates the asset’s or CGU’s recoverable amount. The recoverable amount is the higher of an asset’s or CGU’s fair value less cost of disposal and its value in use. The recoverable amount is determined for an individual asset, unless the asset does not generate cash inflows that are largely independent of those from other assets or groups of assets, in which case, the asset is tested as part of a larger CGU to which it belongs. If the carrying amount of an asset or CGU exceeds its recoverable amount, the asset or CGU is considered impaired and is written down to its recoverable amount. Non-financial assets other than goodwill that were adjusted due to impairment are subsequently reviewed for possible reversal of the impairment at each reporting date.

Intangible assets

(i)Goodwill

For the purpose of impairment testing, the recoverable amount goodwill is allocated to a CGU that is the lowest level with the Group at which goodwill is monitored. If the recoverable amount of the asset (or CGU) is estimated to be less than its carrying amount, the carrying amount of the asset (or CGU) is reduced to its recoverable amount. The difference between the carrying amount and recoverable amount is recognized as an impairment loss in the income statement.

(ii)Rights over natural resources

Costs for the acquisition of rights to explore and develop mineral properties are capitalized and amortized using the straight line method over their useful lives. Useful lives consider the period of extraction for both mineral reserves and mineral resources, which includes a portion of the Company’s inferred resources in the Company’s mining operations in Peru. These mining operations represent over 98% of the Company’s total right to use natural resources.

Management considers that in the case of the rights to use natural resources, which relate almost exclusively to the Peruvian acquired assets, the use of only proven and probable reserves does not provide a realistic indication of the useful life of the mine. In this case management is confident based on testing, continuity of the ore bodies and conversion experience that further inferred resources will be converted into measured and indicated resources, and if they are economically recoverable, that such inferred resources can also be classified as proven and probable reserves. Management is approaching economic decisions affecting the mine on this basis, but has chosen to delay the work required to designate them formally as reserves in accordance with its annual testing plans. In assessing which inferred resources to include so as to best reflect the useful life of the mine, management considers inferred resources that have been included in the strategic mine plan. To be included in the strategic mine plan, inferred resources need to be above the cutoff grade set by management, which means that such resource expect to be economically mined and is therefore commercially viable. This consistent systematic method for inclusion in the strategic mine plan takes management’s view of the mineral price, extraction costs as well as cost inflation into account. In order to convert these inferred resources into measured and indicated resources, the Company would have to conduct additional drilling.

Additional confidence in the existence, commercial viability and economical recovery of such resources may be based on historical experience and available geological information, such as geological information obtained from other operations that are adjoining the Company’s as well as where the Company mines continuations of these other operations’ orebodies. This is in addition to the drilling results obtained by the Company and management’s knowledge of the geological setting of the surrounding areas, which would enable simulations and interpolations to be done with a reasonable degree of accuracy. In instances where management is able to demonstrate the economic recovery of such resources with a high level of confidence based on the specific circumstances, such additional resources, which may also include certain, but not all, of the inferred resources, are included in the calculation of amortization.

Thus, although there is less assurance that mineral resources will eventually be realized as compared to proven and probable reserves, a portion of inferred resources are considered to be economically valuable based on our historical experience and are considered in the useful life of the mine for accounting purposes, as there has been a continuous conversion of the inferred resources into measured and indicated, and then to mineral reserves. The annual conversion rate from inferred mineral resources into measured and indicated mineral resources for the Company’s mining operations in Peru was approximately 97% in 2015, 100% in 2016 and 100% in 2017. The Company included approximately 70% of the Company’s inferred resources in Peru when calculating the expected life of mine for purposes of the period of amortization.

Considering the nature of the Company’s production year on year, the expense calculated under the straight line method is not considered to be materially different to what it would be calculated under the unit of production method. Once the mine is operational, these costs are amortized and considered as a cost of production.

(iii)Stripping costs

In mining operations related to the metal business, it is necessary to remove overburden and other waste to gain access to mineral ore deposits. The process of mining overburden and waste materials is referred to as stripping. During the development of a mine, before production commences, when the stripping activity asset improves access to the ore body, the component of the ore body for which access has been improved can be identified and the costs can be measured reliably, the stripping activity asset is capitalized as part of the investment in the construction of the mine, accounted for as part of intangible assets, and subsequently amortized over the life of the mine on a units of production basis.

Stripping costs incurred during the production phase of operations are treated as a production cost that forms part of the cost of inventory.

(iv)Costs of exploration

The Company capitalizes the costs of exploration when the existence of proven and probable reserves is determined. These costs are amortized using the estimated useful lives of the mining property from the time when commercial exploitation of the reserves begins.

When Management determines that no future economic benefits are expected from the mining property, the accumulated exploration costs are charged to “Other operating expenses, net”.

(v)Mineral studies and research expenditures

Mineral studies and research expenditure are considered operating expenses until such time as the economic feasibility of the commercial exploitation of a certain mine is proven. Once feasibility is proven, the expenditure incurred is capitalized within mine development costs in “construction in progress — property, plant and equipment”. When the mine is operational, the cumulative costs capitalized in relation to exploitation rights are reclassified from “constructions in progress” to “mining projects” and subsequently amortized over the life of the mine on a units of production basis and included in the cost of the product. The capitalized construction costs relating to the plant are reclassified to “equipment and facilities”.

(vi)Use of public assets

Represent the amounts established in the concession contracts regarding the rights to hydroelectric power generation (onerous concession) under use of public assets (“UBP”) agreements.

The accounting entries are made considering the time the installation permit is released, regardless of the disbursement schedule established in the contract. The initial recording of this liability (obligation) and intangible asset (concession rights) corresponds to the amounts of future obligations brought to present value (present value of the cash flow of future payments).

The amortization of the intangible asset is calculated on a straight line basis over the remaining period of the concession. The financial liability is restated at the index established and the adjustment to present value due to the passage of time, reduced by the payments made.

(vii)Computer software

Computer software licenses acquired are recorded as intangible assets on the basis of the costs incurred to acquire and bring to use the specific software. These costs are amortized over the estimated useful life of the software (three to five years).

Costs associated with maintaining computer software programs are recognized as an expense as incurred.

Loans and financings

Loans and financings are recognized initially at fair value, net of transaction costs incurred, and are subsequently carried at amortized cost. Any difference between the proceeds (net of transaction costs) and the total amount payable is recognized in the income statement over the period of the loans using the effective interest rate method.

Loans and financings are classified as current liabilities unless the Company has the unconditional right to defer repayment of the liability for at least 12 months after the reporting period.

Fees paid on the establishment of loan facilities are recognized as transaction costs of the loan to the extent that it is probable that some or all of the facility will be drawn down. In this case, the fee is deferred until the drawdown occurs. To the extent that there is no evidence that it is probable that some or all of the facility will be drawn down, the fee is capitalized as a prepayment for liquidity services and amortized over the period of the facility to which it relates.

Loans and financing costs directly related to the acquisition, construction or production of a qualifying asset that requires a substantial period of time to prepare for its intended use or sale are capitalized as part of the cost of that asset when it is probable that future economic benefits associated with the item will flow to the Company and costs can be measured reliably. The other loans and financing costs are recognized as financial expenses in the period in which they are incurred.

Current and deferred taxes on income

The taxes on income benefit or expense for the period comprises current and deferred taxes.  Taxes on profit are recognized in the income statement, except to the extent that they relate to items recognized in comprehensive income or directly in shareholders’ equity.  In such cases, the taxes are also recognized in comprehensive income or directly in shareholders’ equity respectively.

The current and deferred taxes on income is calculated on the basis of the tax laws enacted or substantively enacted up to balance sheet date in the countries where the entities operate and generate taxable income. Management periodically evaluates positions taken by the Company in the taxes on income returns with respect to situations in which the applicable tax regulations are subject to interpretation. It establishes provisions where appropriate on the basis of amounts expected to be paid to the tax authorities.

The current taxes on income is presented net, separated by taxpaying entity, in liabilities when there are amounts payable, or in assets when the amounts prepaid exceed the total amount due on the reporting date.

Deferred tax assets are recognized only to the extent it is probable that future taxable profits will be available against which the temporary differences and/or tax losses can be utilized.

Deferred tax assets and liabilities are offset when there is a legally enforceable right and an intention to offset them in the calculation of current taxes, generally when they are related to the same legal entity and the same tax authority. Accordingly, deferred tax assets and liabilities in different entities or in different countries are generally presented separately, and not on a net basis.

Deferred tax liabilities and assets are not recognized for temporary differences between the carrying amounts and tax bases of investments in foreign operations where the Company is able to control the timing of the reversal of the temporary differences and it is probable that the differences will not be reversed in the near future.

Deferred taxes on income is provided in full, using the liability method, on temporary differences arising between the tax bases of assets and liabilities and their carrying amounts in the consolidated financial statements. However, deferred tax liabilities are not recognized if they arise from the initial recognition of goodwill. Deferred taxes on income is also not accounted for if it arises from the initial recognition of an asset or liability in a transaction other than a business combination that, at the time of the transaction, affects neither the accounting nor the taxable profit or loss. Deferred taxes on income is determined using tax rates (and laws) that have been enacted or substantially enacted by the end of the reporting period and are expected to apply when the related deferred taxes on income asset is realized or the deferred taxes on income liability is settled.

Provisions

Provisions for tax, civil, labor, environmental and legal claims

Provisions for legal claims (labor, civil, tax and environmental) are recognized when: (i) the Company has a present legal or constructive obligation as a result of past events; (ii) it is probable that an outflow of resources will be required to settle the obligation; and (iii) the amount can be reliably estimated. Provisions do not include future operating losses.

Where there is a number of similar obligations, the likelihood that an outflow will be required in settlement is determined by considering the class of obligations as a whole. A provision is recognized even if the likelihood of an outflow with respect to any one item included in the same class of obligations may be small.

Provisions are measured at the present value of the expenditure expected to be required to settle the obligation using a pre-tax rate that reflects current market assessments of the time value of money and the risks specific to the obligation. The increase in the provision due to the passage of time is recognized as “Financial expenses”.

Asset retirement obligation

The Company recognizes a provision for environmental restoration and for the closure of operating units that correspond to its legal obligation to restore the environment at the termination of its operations.

Provision is made for asset retirement, restoration and environmental costs when the obligation occurs, based on the net present value of estimated future costs with, where appropriate, probability weighting of the different remediation and closure scenarios. The ultimate cost of closedown and restoration is uncertain, and management uses its judgment and experience to determine the potential scope of rehabilitation work required and to provide for the costs associated with that work. Adjustments are made to provisions when the range of possible outcomes becomes sufficiently narrow to permit reliable estimation.

Cost estimates can vary in response to many factors including: changes to the relevant legal or local/national government ownership requirements and any other commitments made to stakeholders; review of remediation and relinquishment options; the emergence of new restoration techniques and the effects of inflation. Experience gained at other mine or production sites is also a significant consideration, although elements of the restoration and rehabilitation of each site are relatively unique to the site and, in some cases, there may be relatively limited restoration and rehabilitation activity and historical precedent against which to benchmark cost estimates. External experts support the cost estimation process where appropriate.

Cost estimates are updated throughout the life of the operation aligned with Internal Policies and these Internal Policies themselves are also subject to periodical updates to maintain these in line with international best practices. The expected timing of expenditure included in cost estimates can also change, for example in response to changes to expectations relating to ore reserves and mineral resources, production rates, operating licenses or economic conditions. Expenditure may occur before and after closure and can continue for an extended period of time depending on the specific site requirements. Some expenditure can continue into perpetuity. In such cases, the provision for these ongoing costs may be restricted to a period for which the costs can be reliably estimated.

On the date of initial recognition of the liability that arises from this obligation, discounted to present value using a risk free rate, the same amount is simultaneously charged to property, plant and equipment in the balance sheet. The selection of appropriate sources on which to base the calculation of the risk-free discount rate used for such retirement, restoration and environmental obligations requires judgment. Subsequently, the liability is increased in each period to reflect the finance cost considered in the initial measurement of the discount. Additionally, the capitalized cost is depreciated based on the useful life of the related asset. Upon settlement of the liability, the Group entities recognize any profit or loss that may arise.

Any reduction in this provision and, therefore, any reduction in the related asset, exceeding the carrying amount of the asset, are immediately recognized in the income statement as “operating costs”.

As a result of all of the above factors, there could be significant adjustments to the provision for close-down, restoration and environmental costs which would affect future financial results.

Judicial deposits

Judicial deposits are presented on a net basis in “Provisions” when there is a corresponding provision. The deposits without corresponding provisions are presented in non-current assets.

Use of public assets

Use of public assets refers to the rights granted by the government to operate potential hydraulic energy (onerous concession), under an agreement for the Use of Public Assets.

The amount is recognized once the operating license is obtained, regardless of the payment schedule established in the contract. The amount is originally recognized as a liability (obligation) and an intangible asset (concession right) which corresponds to the amount of the future obligations discounted to the present value of the future payment cash flow. The financial liability is updated based on the contractual index and the present value adjustment resulting from the lapse of time and reduced by the payments made.

Equity

Common shares are classified in equity. Each time a share premium is paid to the Company for an issued share, the respective share premium is allocated to the share premium reserve account.

Each time the repayment of a share premium is decided, such repayment shall be done pro-rata to the existing shareholders.

The distribution of dividends to the Company’s shareholders is recognized as a liability in the Company’s consolidated financial statements in the period in which the dividends are approved by the Company’s shareholders.

Net revenue

Revenue represents the fair value of the consideration received or receivable for the sale of goods in the ordinary course of the Company’s activities. Revenue is shown net of value-added tax, returns, rebates and discounts, after eliminating sales between the consolidated companies.

The Company recognizes revenue when: (i) the amount of revenue can be reliably measured; (ii) it is probable that future economic benefits will flow to the entity; and (iii) specific criteria have been met for each of the Company’s activities as described below. Revenue will not be deemed to be reliably measured if all sale conditions are not resolved. The Company bases its estimates on historical results, taking into consideration the type of customer, the type of transaction and the specifics of each arrangement.

Revenue recognition is based on the following principles:

Sale of goods: Sales are normally recognized when the goods are delivered to the carrier and the ownership and risks with respect thereto are transferred to the customer.

Revenue from sales of concentrates is determined based on the prices of international quotes and in accordance with the contractual terms. In such cases, revenue is initially recognized at a provisional price which corresponds to the international quoted price at the shipping date. The amount of the provision for settlement is adjusted to reflect future prices, according to international quotes at the closing date of each month, until a final adjustment is carried out to value the sales in accordance with the prices agreed upon with customers, based on the contractual sales terms. The adjustments of provisional settlements are recognized in trade accounts receivable, against sales revenue when:

· The future price, mentioned above, for shipment or delivery, for a determined period (pre-final) settlement, or at the close of an accounting period is different to the price recorded.

· A debit or credit note is issued after the adjustments of the provision for settlement are recognized, based on the final weights or final contents, which results in a higher or lower amount, respectively, compared to the amount of the provision for settlement.

A debit or credit note is issued when the final price has been defined.

Employee benefit expenses

(i)Profit sharing

A provision is recorded to recognize the expenses related to employee profit sharing. This provision is calculated based on the qualitative and quantitative targets established by management and are recorded as “Employee benefits” in the income statement.

(ii)Share-based payments

The subsidiary NEXA PERU operates a cash-settled, share-based compensation plan, under which the company gives certain executives a package of equity instruments (options) as consideration for services received, which is based on the value of equity instruments (“Phantom options”) of the NEXA PERU.

The cost of the cash settled share-based payments plan is initially measured at fair value as at the grant date using the Black-Scholes financial model. This fair value is accrued over the period until the vesting date, with the recognition of the liability. The liability is measured again at fair value at each reporting date, and it is reported up to and including the settlement date, with changes in fair values recognized as expenses of employee benefits in the income statement.

The purpose of such incentive plan is to align a portion of the compensation of the company’s senior executives with the evolution of the NEXA PERU’s market value.

Information by business segment and geographic area

The internal body, which makes decisions regarding the relevant activities of the Company, is comprised of the Executive Officers who report directly to the Chief Executive Officer (“CEO”) who analyzes the results of NEXA and has the final authority over resource allocation decisions and performance assessment over mining and smelting segments. This assessment is based on the fact that NEXA considers that the different mining and smelting units can be combined in its own specific segment due to the fact that they present similar financial performances, similar types of products, productive process and types of clients and regulatory framework.

The internal information used for making decisions is prepared applying accounting measurement bases with managerial adjustments. The sales information is broken down by product, geographical origin location and geographical customer location. The non-current assets are presented by location.

Defined contribution pension plans

The Company, through its subsidiaries abroad, participates in pension plans, managed by a private pension entity, which provide post-employment benefits to employees.

In Brazil, the Company sponsors a defined contribution plan. A defined contribution plan is a pension plan under which the Company pays fixed contributions to a separate entity. The Company has no legal or constructive obligations to make additional contributions should the fund not have sufficient assets to honor the benefits related to employee service in the current or prior periods.

In Peru, termination benefits are recognized in profit or loss when they are paid. This happens when employment is terminated before the normal retirement date or whenever an employee accepts voluntary redundancy in exchange for these benefits.

The employees’ severance indemnities for the length of service of the Company’s staff hired in Peru represent their indemnification rights, calculated in accordance with the laws and regulations in force, which have to be credited to the bank accounts designated by the workers in May and November of each year. The compensation for time of service is equivalent to one (1) additional month’s salary effective at the date of the bank deposit. The Company has no obligations to make any additional payments once the annual deposits to which workers are entitled have been made.

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Basis of preparation of the consolidated financial statements (Tables)

12 Months Ended

Dec. 31, 2017

Basis of preparation of the consolidated financial statements

Schedule of ownership percentages

	Percentage of capital
	2017	2016	Headquarters	Control	Activities
Campos Novos Energia S.A. - “Enercan”	20.98	20.98	Brazil	Indirect	Energy
Capim Branco Energia	12.63	12.63	Brazil	Indirect	Energy
Cia . Minera Gaico S.A.	93.40	93.40	Peru	Indirect	Holding and others
Cia. Magistral S.A.C	100.00	—	Peru	Indirect	Holding and others
Cia. Minera Dona Isabel Ltda.	100.00	100.00	Peru	Indirect	Holding and others
Cia. Minera Shalipayco S.A.C	75.00	75.00	Peru	Indirect	Holding and others
Nexa Resources Atacocha S.A.A. - “NEXA ATACOCHA” (formely Compañia Minera Atacocha S.A.A.)	66.62	66.62	Peru	Indirect	Mining
Nexa Resources Perú S.A.A. - “NEXA PERU” (formely Compañia Minera Milpo S.A.A - “Milpo”)	80.23	80.23	Peru	Indirect	Mining
Consórcio UHE Igarapava	23.93	23.93	Brazil	Indirect	Energy
InPac Holding Limited	100.00	100.00	British Virgin Islands	Indirect	Holding and others
Inversiones Garza Azul S.A.C	100.00	100.00	Peru	Indirect	Holding and others
L.D.O.S.P.E. Empreendimentos e Participações Ltda.	100.00	—	Brazil	Indirect	Energy
L.D.Q.S.P.E. Empreendimentos e Participações Ltda.	100.00	—	Brazil	Indirect	Energy
L.D.R.S.P.E. Empreendimentos e Participações Ltda.	100.00	—	Brazil	Indirect	Energy
Nexa Resources El Porvenir S.A.C. (formely Milpo Andina Peru S.A.C.)	99.99	99.99	Peru	Indirect	Mining
Nexa Resources UK Ltd. - “NEXA UK” (formely Milpo UK Limited)	100.00	100.00	United Kingdom	Indirect	Mining
Minera Bongará S.A.	61.00	61.00	Peru	Indirect	Holding and others
Minera Cerro Colorado S.A.C	99.99	99.00	Peru	Indirect	Holding and others
Minera Chambará S.A.C	15.00	15.00	Peru	Indirect	Holding and others
Minera Pampa de Cobre S.A.C	99.99	99.00	Peru	Indirect	Mining
Minera Rayrock Ltda.	—	84.08	Chile	Indirect	Holding and others
Mineração Dardanelos Ltda.	70.00	70.00	Brazil	Indirect	Holding and others
Mineração Santa Maria Ltda.	99.99	99.99	Brazil	Indirect	Holding and others
Otavi Mining Investments (Pty) Ltd.	100.00	100.00	Namibia	Indirect	Holding and others
Otjitombo Mining Proprietary Ltd.	100.00	100.00	Namibia	Indirect	Holding and others
Pollarix S.A.	33.33	33.33	Brazil	Indirect	Holding and others
Rayrock Antofagasta S.A.C	99.99	100.00	Chile	Indirect	Holding and others
SMRL CMA nº 54	100.00	100.00	Peru	Indirect	Holding and others
SMRL Ltda. Pepita 1	57.50	57.50	Peru	Indirect	Holding and others
Votorantim Andina S.A. - “VASA”	99.99	99.99	Chile	Indirect	Holding and others
Votorantim GmbH	100.00	100.00	Austria	Direct	Holding and others
Votorantim Investimentos Latino-Americanos S.A. - “VILA”	100.00	100.00	Brazil	Indirect	Holding and others
Votorantim Metais Argentina S.A.	—	90.00	Argentina	Indirect	Holding and others
Votorantim Metais Bolívia S.R.L.	—	76.61	Bolivia	Indirect	Holding and others
Nexa Resources Cajamarquilla S.A. - “NEXA CJM” (formely Votorantim Metais Cajamarquilla S.A. - “CJM”)	99.99	99.99	Peru	Direct	Smelting
Nexa Recursos Minerais S.A. - “NEXA BR” (formely Votorantim Metais Zinco S.A. - “VMZ”)	100.00	100.00	Brazil	Direct	Mining / Smelting
Votorantim Metals Cananda Inc.	100.00	100.00	Canada	Indirect	Holding and others
Votorantim Metals Namibia Ltd.	100.00	100.00	Namibia	Indirect	Holding and others
Votorantim US. Inc.	100.00	100.00	United States	Direct	Holding and others

Schedule of revision to financial statements - Income Statement

	(Original) 2016		Adjustment		(Revised) 2016
Net revenue from products sold	1,912,813		52,028		1,964,841
Cost of products sold	(1,387,073	)	(52,028	)	(1,439,101	)
Gross profit	525,740		—		525,740

	(Original) 2015		Adjustment		(Revised) 2015
Net revenue from products sold	1,824,840		40,343		1,865,183
Cost of products sold	(1,422,947	)	(40,343	)	(1,463,290	)
Gross profit	401,893		—		401,893

Schedule of revision to financial statements - Composition of net revenue

	(Original) 2016		Adjustment	(Revised) 2016
Gross Revenue	2,193,867		—	2,193,867
Taxes on sales and returns	(281,054	)	52,028	(229,026	)
Net revenue from products sold	1,912,813		52,028	1,964,841

	(Original) 2015		Adjustment	(Revised) 2015
Gross Revenue	2,072,439		—	2,072,439
Taxes on sales and returns	(247,599	)	40,343	(207,256	)
Net revenue from products sold	1,824,840		40,343	1,865,183

Schedule of revision to financial statements - Revenue by destination

	(Original) 2016	Adjustment	(Revised) 2016
Peru	521,856	52,028	573,884
Brazil	560,878	—	560,878
United States	156,634	—	156,634
Luxembourg	100,631	—	100,631
Korea	66,887	—	66,887
Switzerland	59,873	—	59,873
Chile	67,546	—	67,546
Singapore	42,666	—	42,666
Germany	42,560	—	42,560
Colombia	39,137	—	39,137
Japan	36,005	—	36,005
Austria	22,982	—	22,982
Turkey	19,498	—	19,498
China	12,838	—	12,838
Italy	3,608	—	3,608
Other	159,214	—	159,214
	1,912,813	52,028	1,964,841

	(Original) 2015	Adjustment	(Revised) 2015
Peru	544,107	40,343	584,450
Brazil	534,141	—	534,141
United States	99,884	—	99,884
Luxembourg	98,159	—	98,159
Korea	51,181	—	51,181
Switzerland	135,450	—	135,450
Chile	52,865	—	52,865
Singapore	72,514	—	72,514
Germany	22,348	—	22,348
Colombia	42,007	—	42,007
Japan	32,994	—	32,994
Austria	18,731	—	18,731
Turkey	23,265	—	23,265
China	639	—	639
Italy	1,399	—	1,399
Other	95,156	—	95,156
	1,824,840	40,343	1,865,183

Schedule of revision to financial statements - Revenue by currency

	(Original) 2016	Adjustment	(Revised) 2016
U.S. Dollar	1,362,964	52,028	1,414,992
Real	547,537	—	547,537
Other	2,312	—	2,312
	1,912,813	52,028	1,964,841

	(Original) 2015	Adjustment	(Revised) 2015
U.S. Dollar	1,294,535	40,343	1,334,878
Real	529,218	—	529,218.0
Other	1,087	—	1,087
	1,824,840	40,343	1,865,183

Schedule of revision to financial statements - Expenses by nature

	(Original) 2016	Adjustment	(Revised) 2016
Raw materials and consumables used	904,881	52,028	956,909
Employee benefit expenses	233,755	—	233,755
Depreciation and amortization	275,034	—	275,034
Freight costs	68,962	—	68,962
Services, miscellaneous	89,426	—	89,426
Other Expenses	32,967	—	32,967
	1,605,025	52,028	1,657,053
Reconciliation
Cost of products sold	1,387,073	52,028	1,439,101
Selling expenses	90,647	—	90,647
General and administrative expenses	127,305	—	127,305
	1,605,025	52,028	1,657,053

	(Original) 2015	Adjustment	(Revised) 2015
Raw materials and consumables used	940,190	40,343	980,533
Employee benefit expenses	202,876	—	202,876
Depreciation and amortization	295,258	—	295,258
Freight costs	73,871	—	73,871
Services, miscellaneous	77,772	—	77,772
Other Expenses	23,838	—	23,838
	1,613,805	40,343	1,654,148
Reconciliation
Cost of products sold	1,422,947	40,343	1,463,290
Selling expenses	84,559	—	84,559
General and administrative expenses	106,299	—	106,299
	1,613,805	40,343	1,654,148

Schedule of revision to financial statements - Segment information - intersegment

	Original - 2016
	Mining		Smelting		Elimination		Adjustment		Total
Revenue from products sold - third parties	417,159		1,491,988		—		3,666		1,912,813
Intersegment revenues	490,266		—		(490,266	)	—		—
Total revenue	907,425		1,491,988		(490,266	)	3,666		1,912,813
Cost of products sold	(513,135	)	(1,260,519	)	490,266		(103,685	)	(1,387,073	)
Gross Profit	394,290		231,469		—		(100,019	)	525,740

	Revised - 2016
	Mining		Smelting		Elimination		Adjustment		Total
Revenue from products sold - third parties	469,187		1,491,988		—		3,666		1,964,841
Intersegment revenues	438,238		—		(438,238	)	—		—
Total revenue	907,425		1,491,988		(438,238	)	3,666		1,964,841
Cost of products sold	(513,135	)	(1,260,519	)	438,238		(103,685	)	(1,439,101	)
Gross Profit	394,290		231,469		—		(100,019	)	525,740

	Original - 2015
	Mining		Smelting		Elimination		Adjustment		Total
Revenue from products sold - third parties	380,320		1,421,307		—		23,213		1,824,840
Intersegment revenues	390,384		—		(390,384	)	—		—
Total revenue	770,704		1,421,307		(390,384	)	23,213		1,824,840
Cost of products sold	(532,097	)	(1,170,545	)	390,384		(110,689	)	(1,422,947	)
Gross Profit	238,607		250,762		—		(87,476	)	401,893

	Revised - 2015
	Mining		Smelting		Elimination		Adjustment		Total
Revenue from products sold - third parties	420,663		1,421,307		—		23,213		1,865,183
Intersegment revenues	350,041		—		(350,041	)	—		—
Total revenue	770,704		1,421,307		(350,041	)	23,213		1,865,183
Cost of products sold	(532,097	)	(1,170,545	)	350,041		(110,689	)	(1,463,290	)
Gross Profit	238,607		250,762		—		(87,476	)	401,893

Schedule of revision to financial statements - Segment information - revenue

	Original - 2016
	Net revenue from products sold	Cost of products sold		Gross profit
Brazil	714,946	(473,006	)	241,940
Peru	1,178,354	(896,940	)	281,414
Holding	19,513	(17,127	)	2,386
Total	1,912,813	(1,387,073	)	525,740

	Revised - 2016
	Net revenue from products sold	Cost of products sold		Gross profit
Brazil	714,946	(473,006	)	241,940
Peru	1,230,382	(948,967	)	281,415
Holding	19,513	(17,128	)	2,385
Total	1,964,841	(1,439,101	)	525,740

	Original - 2015
	Net revenue from products sold	Cost of products sold		Gross profit
Brazil	665,573	(460,284	)	205,289
Peru	1,159,264	(962,663	)	196,601
Holding	3	—		3
Total	1,824,840	(1,422,947	)	401,893

	Revised - 2015
	Net revenue from products sold	Cost of products sold		Gross profit
Brazil	665,573	(460,284	)	205,289
Peru	1,199,607	(1,003,006	)	196,601
Holding	3	—		3
Total	1,865,183	(1,463,290	)	401,893

Schedule of revision to financial statements - Earnings per share

	(Original)			(Restated)
	2016	Adjustment		2016
Earnings per share in US Dollars	1.37	(0.22	)	1.15

	(Original)			(Restated)
	2015		Adjustment	2015
Earnings per share in US Dollars	(74.60	)	5.52	(69.08	)

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Financial risk management (Tables)

12 Months Ended

Dec. 31, 2017

Financial risk management

Summary of financial assets and liabilities in foreign currency

	2017	2016
Assets denominated in foreign currency
Cash, cash equivalents and financial investments	229,876	154,693
Derivative financial instruments	4,280	10,005
Trade accounts receivable	66,834	45,194
	300,990	209,892
Liabilities denominated in foreign currency
Loans and financing	161,706	95,124
Derivative financial instruments	3,634	—
Trade payables	78,286	61,075
	243,626	156,199
Net exposure	57,364	53,693

Summary of estimated future cash flow

	Less than 1 year	Between 1 and 3 years	Between 3 and 5 years	Over 5 years	Total
At December 31, 2017
Loans and financing	102,294	373,324	236,927	1,228,474	1,941,018
Derivative financial instruments	12,588	2,449	—	—	15,037
Trade payables	329,814	—	—	—	329,814
Confirming payable	111,024	—	—	—	111,024
Salaries and payroll charges	79,798	—	—	—	79,798
Dividends payable	4,138	—	—	—	4,138
Related parties	87,686	2,238	—	—	89,924
Provisions - Asset Retirement Obligation	7,526	53,429	33,186	237,788	331,929
Use of public assets	1,740	3,755	4,233	45,309	55,037
	736,607	435,195	274,346	1,511,571	2,957,719
At December 31, 2016
Loans and financing	104,191	438,569	432,587	375,480	1,350,827
Derivative financial instruments	37,458	—	—	—	37,458
Trade payables	282,241	—	—	—	282,241
Confirming payable	102,287	—	—	—	102,287
Salaries and payroll charges	70,022	—	—	—	70,022
Dividends payable	7,185	—	—	—	7,185
Related parties	222,917	7,596	—	—	230,513
Provisions - Asset Retirement Obligation	33,143	25,296	35,813	123,827	218,079
Use of public assets	1,754	3,832	4,319	51,449	61,354
	861,198	475,293	472,719	550,756	2,359,966

Summary of net debt ratio

	Note	2017		2016		2015
Loans and financing	16	1,447,299		1,144,385		1,056,210
Cash and cash equivalents	8	(1,019,037	)	(915,576	)	(621,415	)
Derivative financial instruments	5.4	3,260		16,718		(10,105	)
Financial investments	9	(206,547	)	(119,498	)	(57,856	)
Net debt (A)		224,975		126,029		366,834
Profit for the year		165,265		110,509		(139,796	)
Plus (less):
Results of investees		(60	)	158		256
Results of investees - Discontinued operations		—		—		318
Depreciation and amortization	14 and 15	270,454		275,034		295,258
Net financial results	29	130,181		(79,081	)	341,931
Taxes on income	20(a)	106,194		98,383		(38,779	)
EBITDA		672,034		405,003		459,188
Exceptional items
Gains on sales of investments	28	(4,588	)	(408	)	—
Impairment of other assets		73		308		—
(Reversal) Impairment - property, plant, equipment	28	—		(979	)	8,574
Adjusted EBITDA (B)		667,519		403,924		467,762
Gearing ratio (A/B)		0.34		0.31		0.78

Reconciliation of net debt

	Cash and cash equivalents		Financial investments		Derivative financial instruments		Loans and financing		Net debt
Net debt as at 1 January 2017	(915,576	)	(119,498	)	16,718		1,144,385		126,029
Cash flows	(103,413	)	(65,661	)	39,006		236,306		106,238
Foreign exchange ajustments	(48	)	—		—		(2,873	)	(2,921	)
Other non-cash movements	—		(21,388	)	(52,464	)	69,481		(4,371	)
Net debt as at 31 December 2017	(1,019,037	)	(206,547	)	3,260		1,447,299		224,975

Classification of financial assets and liabilities in the fair value hierarchy

		2017
		Fair value measured based on
		Price quoted in an active market	Valuation technique supported by observable prices
	Note	Level 1	Level 2	Total fair value
Assets
Cash and cash equivalents	8	1,019,037	—	1,019,037
Financial investments	9	134,168	72,379	206,547
Derivative financial instruments	5.4	—	11,777	11,777
		1,153,205	84,156	1,237,361
Liabilities
Loans and financing	16(a)	1,120,901	414,231	1,535,132
Derivative financial instruments	5.4	—	15,037	15,037
		1,120,901	429,268	1,550,169

		2016
		Fair value measured based on
		Price quoted in an active market	Valuation technique supported by observable prices
	Note	Level 1	Level 2	Total fair value
Assets
Cash and cash equivalents	8	915,576	—	915,576
Financial investments	9	65,964	53,534	119,498
Derivative financial instruments	5.4	—	20,740	20,740
		981,540	74,274	1,055,814
Liabilities
Loans and financing	16(a)	342,156	808,729	1,150,885
Derivative financial instruments	5.4	—	37,458	37,458
		342,156	846,187	1,188,343

Summary of derivative financial instruments and the underlying hedged items

	Principal			Average terms	Fair value				Realized gain (loss)		Fair value by maturity
Program	2017	2016	per unit	(days)	2017		2016		2017		2018		2019		2020
Hedging instrument for sales of zinc at a fixed price
Zinc forward	2,230	615	ton	127	603		369		1,288		589		14		—
					603		369		1,288		589		14		—
Hedging instrument for mismatches of quotation periods
Zinc forward	240,747	146,515	ton	23	(4,304	)	4,471		(2,183	)	(4,304	)	—		—
Silver forward	238	—	k oz	17	196		—		(24	)	196		—		—
					(4,108	)	4,471		(2,207	)	(4,108	)	—		—
Hedging instrument for the operating margin of metals
Zinc forward	—	10,790	—	—	—		(7,110	)	—		—		—		—
US Dollar forward	—	8,039	—	—	—		1,784		—		—		—		—
					—		(5,326	)	—		—		—		—
Hedging instrument for interest rates in US Dollar
LIBOR floating rate vs. US Dollar fixed rate swaps	31,393	—	USD	849	646		—		(1,200	)	(1,186	)	(1,543	)	3,375
					646		—		(1,200	)	(1,186	)	(1,543	)	3,375
Total (assets and liabilities, net)					(2,859	)	(486	)	(2,119	)	(4,705	)	(1,529	)	3,375

Summary of hedge accounting derivative operations and their fair values

	Principal			Average terms	Fair value				Realized gain (loss)		Fair value by maturity
Program	2017	2016	per unit	(days)	2017		2016		2017		2018
Hedging instruments for mismatches of quotation periods - Fair value
Zinc forward	87,693	22,390	ton	43	(3,319	)	32		(12,310	)	(3,319	)
					(3,319	)	32		(12,310	)	(3,319	)
Hedging instruments for mismatches of quotation periods - Cash flow
Zinc forward	58,800	43,294	ton	47	2,986		(1,728	)	4,450		2,986
Silver forward	265	—	k oz	58	(68	)	—		(94	)	(68	)
					2,918		(1,728	)	4,356		2,918
Hedge accounting - Cash flow hedge
Zinc forward	—	94,559	—	—	—		(22,967	)	(43,898	)	—
Copper forward	—	540	—	—	—		210		(171	)	—
US Dollar forward	—	93,467	—	—	—		8,221		15,134		—
					—		(14,536	)	(28,935	)	—
					(401	)	(16,232	)	(36,889	)	(401	)
Current assets					7,483		20,740
Non-current assets					4,294		—
Current liabilities					(12,588	)	(37,458	)
Non-current liabilities					(2,449	)	—
					(3,260	)	(16,718	)

Schedule of Sensitivity analysis

· Scenario I: considers a change in the market forward yield curves and quotations as of December 31, 2017, according to the base scenario defined by the Company for March 31, 2018.

· Scenario II: considers a change of + or -25% in the market forward yield curves as of December 31, 2017.

· Scenario III: considers a change of + or -50% in the market forward yield curves as of December 31, 2017.

					Impacts on profit (loss)												Impacts on comprehensive income
					Scenario I				Scenarios II e III								Scenario I		Scenarios II e III
Risk factor	Cash and cash equivalents and financial investments	Loans and financing	Principal of derivative financial instruments	Unit	Changes from 2017		Results of scenario I		-25%		-50%		+25%		+50%		Results of scenario I		-25%		-50%		+25%		+50%
Exchange variation rate
USD	11,339	40,274	31,393	USD	-3.81	%	(153	)	(3,328	)	(17,218	)	(897	)	(3,906	)	—		—		—		—		—
BRL	203,392	161,706	—	—	3.97	%	—		—		—		—		—		6,127		53,441		156,447		(28,963	)	(49,564	)
EUR	1,692	—	—	EUR	-1.66	%	(28	)	(423	)	(846	)	423		846		—		—		—		—		—
PEN	22,830	—	—	PEN	0.68	%	155		(5,707	)	(11,415	)	5,707		11,415		—		—		—		—		—
Interest rates
BRL - CDI	202,311	70,720	103,849	BRL	0 bps		—		(2,029	)	(4,044	)	2,043		4,098
USD - LIBOR	—	130,610	1,282,900	USD	-2 bps		14		217		435		(217	)	(435	)	(0	)	(6	)	(12	)	6		12
US Dollar coupon	—	—	31,393	USD	3 bps		(21	)	515		1,047		(499	)	(981	)	—		—		—		—		—
Price - commodities
Zinc	—	—	389,470	ton	-2.90	%	13,073		51,744		103,488		(51,744	)	(103,488	)	(580	)	(2,297	)	(4,594	)	2,297		4,594
Silver	—	—	503	k oz	5.20	%	(9	)	281		562		(281	)	(562	)	(36	)	1,124		2,248		(1,124	)	(2,248	)

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Financial instruments by category (Tables)

12 Months Ended

Dec. 31, 2017

Financial instruments by category

Schedule of financial instruments analysis

		2017
Assets per balance sheet	Note	Loans and receivables	Assets held for trading	Held-to- maturity investments	Derivatives used for hedging	Total
Cash and cash equivalents	8	1,019,037	—	—	—	1,019,037
Financial investments	9	—	206,547	—	—	206,547
Derivative financial instruments	5.4	—	8,811	—	2,966	11,777
Trade accounts receivable	10	182,713	—	—	—	182,713
Related parties	13	738	—	—	—	738
		1,202,488	215,358	—	2,966	1,420,812

		2017
Liabilities per balance sheet	Note	Liabilities at fair value through profit or loss	Derivatives used for hedging	Other financial liabilities	Total
Loans and financing	16	—	—	1,447,299	1,447,299
Derivative financial instruments	5.4	12,842	2,195	—	15,037
Trade payables		—	—	329,814	329,814
Confirming payable	17	—	—	111,024	111,024
Use of public assets	22	—	—	24,309	24,309
Related parties	13	—	—	89,924	89,924
		12,842	2,195	2,002,370	2,017,407

		2016
Assets per balance sheet	Note	Loans and receivables	Assets held for trading	Held-to- maturity investments	Derivatives used for hedging	Total
Cash and cash equivalents	8	915,576	—	—	—	915,576
Financial investments	9	—	119,498	—	—	119,498
Derivative financial instruments	5.4	—	6,649	—	14,091	20,740
Trade accounts receivable	10	120,062	—	—	—	120,062
Related parties	13	400,798	—	—	—	400,798
		1,436,436	126,147	—	14,091	1,576,674

		2016
Liabilities per balance sheet	Note	Liabilities at fair value through profit or loss	Derivatives used for hedging	Other financial liabilities	Total
Loans and financing	16	—	—	1,144,385	1,144,385
Derivative financial instruments	5.4	2,564	34,894	—	37,458
Trade payables		—	—	282,241	282,241
Confirming payable	17	—	—	102,287	102,287
Use of public assets	22	—	—	25,920	25,920
Related parties	13	—	—	230,513	230,513
		2,564	34,894	1,785,346	1,822,804

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Credit quality of financial assets (Tables)

12 Months Ended

Dec. 31, 2017

Credit quality of financial assets

Schedule of credit quality of financial assets

	2017			2016
	Local rating	Global rating	Total	Local rating	Global rating	Total
Cash and cash equivalents
AA+	1,089	—	1,089	5,917	—	5,917
AA-	—	115,269	115,269	13,699	250,038	263,737
A+	—	172,052	172,052	4,919	109,544	114,463
A	—	235,445	235,445	—	65,398	65,398
A-	3	86,189	86,192	15,515	94,454	109,969
BBB+	—	96,436	96,436	75,952	20	75,972
BBB	—	110,733	110,733	121,111	209	121,320
BB	—	—	—	2,239	—	2,239
No rating	—	201,821	201,821	80,365	76,196	156,561
	1,092	1,017,945	1,019,037	319,717	595,859	915,576
Financial investments
AA+	17,111	—	17,111	—	—	—
AA-	180,127	4,238	184,365	113,732	—	113,732
A-	5,053	—	5,053	—	3,225	3,225
No rating	—	18	18	—	2,541	2,541
	202,291	4,256	206,547	113,732	5,766	119,498
Derivative financial instruments
AA-	4,769	3,634	8,403	5,511	—	5,511
A+	—	3,141	3,141	1,587	80	1,667
A	—	233	233	—	4,826	4,826
A-	—	—	—	—	8,736	8,736
	4,769	7,008	11,777	7,098	13,642	20,740
	208,152	1,029,209	1,237,361	440,547	615,267	1,055,814

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Cash and cash equivalents (Tables)

12 Months Ended

Dec. 31, 2017

Cash and cash equivalents

Schedule of cash and cash equivalents

	2017	2016
Cash and banks	319,920	338,054
Term deposits	699,117	577,522
	1,019,037	915,576

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Financial investments (Tables)

12 Months Ended

Dec. 31, 2017

Financial investments

Summary of financial investments held for trading

Held for trading	2017	2016
Investment fund quotas (i)	138,945	95,504
Bank Deposit Certificate	42,067	15,042
Repurchase agreements	18,289	—
Credit Rights Investment Funds	5,053	4,682
Financial Treasury Bills	1,123	4,270
Other	1,070	—
	206,547	119,498

Investments in Brazil represent government and financial institution bonds, indexed to the interbank deposit rate.

(i)The shares held in the investment fund relate to a fund that is exclusively held by VSA and its subsidiaries and NEXA’s stake in this fund is 11% (2016: 8%). The composition of the investment fund’s portfolio is as follows (pro rata to the Company’s stake):

	2017	2016
Repurchase agreements - Public securities	131,999	60,803
Repurchase agreements	5,900	20,797
Bank Deposit Certificate	—	13,009
Financial Treasury Bills	1,046	891
Credit Right Investment Funds	—	4
	138,945	95,504

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Trade accounts receivable (Tables)

12 Months Ended

Dec. 31, 2017

Trade accounts receivable.

Schedule of composition of trade accounts receivable

	Note	2017		2016
Trade receivables		181,084		115,291
Related parties	13	3,775		6,389
Provision for uncollectible trade receivables		(2,146	)	(1,618	)
		182,713		120,062

Schedule of changes in provision for uncollectible trade receivables

	2017		2016
Balance at the beginning of the year	(1,618	)	(2,047	)
Reversals (additions), net	(521	)	653
Exchange variation losses	(7	)	(224	)
Balance at the end of the year	(2,146	)	(1,618	)

Schedule of analysis of trade accounts receivable by currency

	2017	2016
Brazilian Real	66,486	44,924
US Dollar	115,879	74,868
Other	348	270
	182,713	120,062

Schedule of aging of trade accounts receivable

	2017		2016
To fall due	163,196		113,155
Up to 3 months	19,775		6,054
From 3 to 6 months	914		1,169
Over 6 months	974		1,302
	184,859		121,680
Provision for uncollectible trade receivables	(2,146	)	(1,618	)
	182,713		120,062

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Inventory (Tables)

12 Months Ended

Dec. 31, 2017

Inventory.

Schedule of composition of inventory

	2017		2016
Finished products	106,026		121,969
Semi-finished products	85,458		65,054
Raw materials	30,128		17,511
Auxiliary materials and consumables	81,261		104,972
Imports in transit	41,878		20,631
Other	863		15
Provision for obsolete and slow-moving inventory	(20,736	)	(38,384	)
	324,878		291,768

Schedule of changes in provision for obsolete and slow-moving inventory

	2017										2016
	Finished products		Semi- finished products		Raw materials		Auxiliary materials and consumables		Total		Total
Balance at the beginning of the year	(768	)	(10,167	)	(153	)	(27,296	)	(38,384	)	(36,985	)
Reversals (additions), net	727		(2	)	(63	)	16,773		17,435		3,090
Exchange variation gains (losses)	1		150		2		60		213		(4,489	)
Balance at the end of the year	(40	)	(10,019	)	(214	)	(10,463	)	(20,736	)	(38,384	)

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Taxes recoverable (Tables)

12 Months Ended

Dec. 31, 2017

Taxes Recoverable.

Schedule of taxes recoverable

	2017	2016
Value-added Tax on Sales and Services	50,616	64,428
Corporate taxes on Net Income	25,165	34,130
Social Contribution on Revenue	18,824	16,831
Social Integration Program	4,302	3,959
Other	13,737	10,384
	112,644	129,732
Current	80,134	102,996
Non-current	32,510	26,736
	112,644	129,732

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Related parties (Tables)

12 Months Ended

Dec. 31, 2017

Related parties.

Schedule of related parties transactions

	Trade accounts receivable		Non-current assets		Trade payables		Dividends payable		Current and non-current liabilities
	2017	2016	2017	2016	2017	2016	2017	2016	2017	2016
Parent
Votorantim S.A. (i)	8	75	3	3	336	257	—	—	87,686	52,873
Related parties
Companhia Brasileira de Alumínio (ii)	1,843	3,847	—	399,725	5,246	9,064	—	2,423	13	5,614
Votorantim Cimentos S.A.	1,696	1,891	735	750	47	24	—	—	—	—
Other	228	576	—	320	1,414	680	655	—	2,225	1,956
Non-controlling interests (iii)	—	—	—	—		—	3,483	4,762	—	170,070
	3,775	6,389	738	400,798	7,043	10,025	4,138	7,185	89,924	230,513
Current	3,775	6,389		—	7,043	10,025	4,138	7,185	87,686	222,917
Non-current		—	738	400,798		—	—	—	2,238	7,596
	3,775	6,389	738	400,798	7,043	10,025	4,138	7,185	89,924	230,513

(i) The compensation to VSA of an amount equivalent to the economic benefits derived from the Energy Assets was calculated based on the difference between a predetermined comparable market rate and the cost of producing the energy consumed by the Brazilian subsidiaries, resulting in an additional liability of US$24,928 for the period January to June 2017 (and US$ 52,873 in 2016). In addition, an accrual of US$ 62,733 was recorded, due to the right to retain the Energy Assets, as described in note 1 (vii), and the Energy Assets compensation related to December 2016 was paid, as described in note 1 (iii);

(ii) CBA liquidated the amount related to the transaction mentioned in note 1 (i);

(iii) The responsibility of the put option that had been granted by the Company to the minority shareholders amounting US$ 170,070 was transferred to VSA, as per note 1 (vi). After the IPO, the obligation expired as part of the termination of the shareholders’ agreement.

Schedule of financial results of related party transactions

	Sales			Purchases			Financial results
	2017	(Revised) 2016	(Revised) 2015	2017	(Revised) 2016	(Revised) 2015	2017	(Revised) 2016	(Revised) 2015
Related parties
Companhia Brasileira de Alumínio	2,125	70	23	42,434	31,162	3,924	1,012	3,582	—
Votoratim Metais S.A. (i)	—	—	—	—	51	29	—	3,583	5,702
Votener - Votorantim Comercializadora de Energia Ltda.	—	—	12,436	13,510	13,400	28,869	—	—	—
Votorantim Cimentos S.A.	138	45	73	365	273	338	—	—	—
Other	—	2,856	1,265	1,134	1,427	9,755	—	—	—
	2,263	2,971	13,797	57,443	46,313	42,915	1,012	7,165	5,702

(i) Votorantim Metais S.A. was merged into CBA in July 2016.

Schedule of key management compensation

	2017	2016	2015
Short-term benefits to managers	6,668	7,310	4,945
Other long-term benefits to key management	1,162	1,686	836
	7,830	8,996	5,781

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Property, plant and equipment (Tables)

12 Months Ended

Dec. 31, 2017

Property, plant and equipment

Schedule of property, plant and equipment

	2017
					Machinery,						Assets and
	Land and		Dam and		equipment and				Furniture and		projects under		Asset retirement
	improvements		buildings		facilities		Vehicles		fixtures		construction		obligation (ARO )		Mining projects		Other		Total
Balance at the beginning of the year
Cost	24.036		980.242		2.466.265		22.263		6.895		219.254		132.824		271.466		7.345		4.130.590
Accumulated depreciation	(257	)	(435.372	)	(1.485.939	)	(20.440	)	(4.443	)	—		(96.108	)	(102.828	)	(6.741	)	(2.152.128	)
Net balance	23.779		544.870		980.326		1.823		2.452		219.254		36.716		168.638		604		1.978.462
Acquisitions	46		100		5.761		272		307		185.688		4.303		240		—		196.717
Disposals	(930	)	(92	)	(2.915	)			(121	)	(6.917	)	—		—		(7	)	(10.982	)
Depreciation	(22	)	(34.175	)	(142.519	)	(1.174	)	(509	)	—		(5.834	)	(11.121	)	(83	)	(195.437	)
Exchange variation losses	(231	)	(4.309	)	(6.381	)	(101	)	(9	)	(3.965	)	(1.839	)	(2.115	)	(8	)	(18.958	)
Transfers	1.573		71.152		83.297		2.236		131		(158.559	)	—		2.841		—		2.671
Cost and interest revision	—		—		—		—		—		—		43.789		—		—		43.789
Transfers of assets held for sale	—		—		252		—		—		—		—		—		—		252
Balance at the end of the year	24.215		577.546		917.821		3.056		2.251		235.501		77.135		158.483		506		1.996.514
Cost	24.490		1.030.686		2.422.254		21.135		6.743		235.501		178.662		243.938		7.177		4.170.586
Accumulated depreciation	(275	)	(453.140	)	(1.504.433	)	(18.079	)	(4.492	)	—		(101.527	)	(85.455	)	(6.671	)	(2.174.072	)
Net balance at the end of the year	24.215		577.546		917.821		3.056		2.251		235.501		77.135		158.483		506		1.996.514
Average annual depreciation rates - %	—		4		7		24		10		—		5		8		—		—

					Machinery,						Assets and
	Land and		Dam and		equipment and				Furniture and		projects under		Asset retirement
	improvements		buildings		facilities		Vehicles		fixtures		construction		obligation (ARO)		Mining projects		Other		Total
Balance at the beginning of the year
Cost	20,657		816,001		2,223,583		20,551		6,278		206,094		116,695		246,208		6,079		3,662,146
Accumulated depreciation	(85	)	(332,034	)	(1,259,830	)	(18,066	)	(3,441	)	—		(74,229	)	(85,544	)	(5,563	)	(1,778,792	)
Net balance	20,572		483,967		963,753		2,485		2,837		206,094		42,466		160,664		516		1,883,354
Acquisitions	—		—		489				2		151,302		148		28,915		—		180,856
Disposals	(46	)	(593	)	(1,525	)	(95	)	(37	)	(42	)	—		(11,000	)	(1	)	(13,339
Depreciation	(20	)	(31,145	)	(145,450	)	(1,487	)	(477	)	—		(7,301	)	(14,096	)	(67	)	(200,043
Reversal of provision for asset impairment (i)											979								979
Exchange variation gains	2,274		38,640		64,510		259		43		16,987		4,589		2,652		139		130,093
Transfers	999		54,001		98,801		661		84		(156,066	)			1,503		17
Cash flow review and restatement of interest rates	—		—		—		—		—		—		(3,186	)	—		—		(3,186	)
Assets transferred to held for sale	—		—		(252	)	—		—		—		—		—		—		(252	)
Balance at the end of the year	23,779		544,870		980,326		1,823		2,452		219,254		36,716		168,638		604		1,978,462
Cost	24,036		980,242		2,466,265		22,263		6,895		219,254		132,824		271,466		7,345		4,130,590
Accumulated depreciation	(257	)	(435,372	)	(1,485,939	)	(20,440	)	(4,443	)	—		(96,108	)	(102,828	)	(6,741	)	(2,152,128	)
Net balance at the end of he year	23,779		544,870		980,326		1,823		2,452		219,254		36,716		168,638		604		1,978,462
Average annual depreciation rates -%	—		4		7		21		11		—		7		8		—		—

(i)The Company assesses at each balance sheet date whether there is objective evidence that any item of property, plant and equipment is impaired. No impairment was identified during 2017.

Schedule of carrying amount of land and equipment acquired through finance leases

	2017		2016
Cost	19,763		13,794
Accumulated depreciation	(10,930	)	(9,657	)
	8,833		4,137

Schedule of assets and projects under constructions

	2017	2016
Mining projects	101,922	91,174
Acquisition and renovation of equipment	42,239	52,284
Security, health and enviroment projects	35,858	44,674
New production line construction	25,477	5,472
Information technology	3,084	151
Modernization and increased production projects	10,563	10,004
Other	16,358	15,495
	235,501	219,254

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Intangible assets (Tables)

12 Months Ended

Dec. 31, 2017

Intangible assets

Schedule of reconciliation of changes in intangible assets

	2017
	Goodwill		Rights to use natural resources		Software		Use of public assets		Assets and projects under construction		Other		Total
Balance at the beginning of the year
Cost	675,561		1,673,091		1,507		11,581		6,974		35,053		2,403,767
Accumulated amortization	—		(469,381	)	(1,106	)	(4,159	)	—		(25,969	)	(500,615	)
Net balance	675,561		1,203,710		401		7,422		6,974		9,084		1,903,152
Acquisitions	—		—		921		—				—		921
Disposals	—		—		(36	)	—				—		(36	)
Amortization	—		(74,024	)	(576	)	(394	)			(23	)	(75,017	)
Exchange variation losses	(2,274	)	(682	)	(21	)	(96	)	(424	)	(133	)	(3,630	)
Transfers	—		—		4,768		—		(6,546	)	(893	)	(2,671	)
Balance at the end of the year	673,287		1,129,004		5,457		6,932		4		8,035		1,822,719
Cost	673,287		1,672,931		21,823		11,410		4		28,847		2,408,302
Accumulated amortization	—		(543,927	)	(16,366	)	(4,478	)	—		(20,812	)	(585,583	)
Net balance at the end of the year	673,287		1,129,004		5,457		6,932		4		8,035		1,822,719
Average annual amortization rates %	—		5		20		3		—		—		—

	2016
	Goodwill	Rights to use natural resources		Software		Use of public assets		Assets and projects under construction		Other		Total
Balance at the beginning of the year
Cost	674,769	1,669,901		469		9,666		5,238		30,018		2,390,061
Accumulated amortization	—	(395,665	)	(340	)	(3,148	)	—		(22,029	)	(421,182	)
Net balance	674,769	1,274,236		129		6,518		5,238		7,989		1,968,879
Acquisitions	—			—		—		2,133				2,133
Amortization	—	(74,013	)	(73	)	(363	)	—		(542	)	(74,991	)
Exchange variation gains (losses)	792	3,487		(41	)	1,267		—		1,626		7,131
Transfers	—	—		386		—		(397	)	11
Balance at the end of the year	675,561	1,203,710		401		7,422		6,974		9,084		1,903,152
Cost	675,561	1,673,091		1,507		11,581		6,974		35,053		2,403,767
Accumulated amortization	—	(469,381	)	(1,106	)	(4,159	)	—		(25,969	)	(500,615	)
Net balance at the end of the year	675,561	1,203,710		401		7,422		6,974		9,084		1,903,152
Average annual amortization rates %	—	5		20		3		—		—		—

Schedule of main assumptions used for impairment testing of goodwill

	Key Assumptions
Zinc (US$ per ton)	2,509
Copper (US$ per ton)	6,362
Discount Rate	10.6	%

	LOM (Years)
Mines	from 7 to 12
Greenfield	from 13 to 27

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Loans and Financings (Tables)

12 Months Ended

Dec. 31, 2017

Loans and financings

Schedule of analysis of the loans and financings

		Current		Non-current		Total		Fair value
Type	Average annual charges	2017	2016	2017	2016	2017	2016	2017	2016
Eurobonds - USD	5.19% fixed USD	8,778	4,054	1,032,664	343,000	1,041,442	347,054	1,120,901	342,156
Debt with banks	LIBOR 3M + 2.57% /LIBOR 6M + 2.51%	435	24,038	199,179	662,743	199,614	686,781	214,293	712,371
BNDES	TJLP + 2.68% / 4.74% fixed BRL / SELIC + 2.78% / UMBNDES + 2.44%	19,795	32,619	73,653	67,672	93,448	100,291	85,969	86,908
Debentures	107.77% CDI	8,885	504	32,403	3,822	41,288	4,326	41,405	4,235
Export credit note	118.00% CDI / LIBOR 3M + 1.85%	1,102	—	61,622	—	62,724	—	64,058	—
FINEP	TJLP + 0.68%	677	682	2,062	2,743	2,739	3,425	2,640	3,038
FINAME	4.59% fixed BRL	398	407	1,383	1,804	1,781	2,211	1,604	1,828
Other	5,93% fixed USD	771	297	3,492	—	4,263	297	4,262	349
		40,841	62,601	1,406,458	1,081,784	1,447,299	1,144,385	1,535,132	1,150,885
Current portion of long term loans and financing (principal)		28,019	57,137
Interest on loans and financing		12,822	5,464
		40,841	62,601

Schedule of maturity profile of the loans and financings

The maturity profile of loans and financing at December 31, 2017, was as follows:

	Principal amount
	2018	2019	2020	2021	2022	2023	2024	As from 2025	Total
Eurobonds - USD	—	—	—	—	—	343,000	—	700,000	1,043,000
Debt with banks	—	31,111	84,444	84,444	—	—	—	—	199,999
BNDES	19,732	23,379	16,288	12,703	9,500	5,284	3,067	4,251	94,204
Debentures	8,119	8,119	8,119	8,119	8,119	—	—	—	40,595
Export credit note	—	—	61,623	—	—	—	—	—	61,623
FINEP	669	669	669	669	56	—	—	—	2,732
FINAME	395	392	374	315	231	70	1		1,778
Other	772	818	866	918	889	—	—	—	4,263
	29,687	64,488	172,383	107,168	18,795	348,354	3,068	704,251	1,448,194

	Interest accrual and costs
	2018	2019		2020		2021		2022		2023		2024		As from 2025		Total
Eurobonds - USD	8,778	(1,177	)	(1,227	)	(1,280	)	(1,337	)	(1,172	)	(1,160	)	(2,983	)	(1,558	)
Debt with banks	435	(281	)	(281	)	(258	)	—		—		—		—		(385	)
BNDES	63	(225	)	(179	)	(165	)	(109	)	(60	)	(34	)	(47	)	(756	)
Debentures	767	(31	)	(25	)	(9	)	(9	)	—		—		—		693
Export credit note	1,101	—		—		—		—		—		—		—		1,101
FINEP	7	—		—		—		—		—		—		—		7
FINAME	3	—		—		—		—		—		—		—		3
Other	—	—		—		—		—		—		—		—
	11,154	(1,714	)	(1,712	)	(1,712	)	(1,455	)	(1,232	)	(1,194	)	(3,030	)	(895	)

	Total
	2018	2019		2020		2021		2022		2023	2024		As from 2025	Total
Eurobonds - USD	8,778	(1,177	)	(1,227	)	(1,280	)	(1,337	)	341,828	(1,160	)	697,017	1,041,442
Debt with banks	435	30,830		84,163		84,186		—		—	—		—	199,614
BNDES	19,795	23,154		16,109		12,538		9,391		5,224	3,033		4,204	93,448
Debentures	8,886	8,088		8,094		8,110		8,110		—	—		—	41,288
Export credit note	1,101	—		61,623		—		—		—	—		—	62,724
FINEP	676	669		669		669		56		—	—		—	2,739
FINAME	398	392		374		315		231		70	1		—	1,781
Other	772	818		866		918		889		—	—		—	4,263
	40,841	62,774		170,671		105,456		17,340		347,122	1,874		701,221	1,447,299
	4%	4%		12%		7%		1%		24%	0%		48%	100%

Schedule of movements in loans and financings

	2017		2016
Balance at the beginning of the year	1,144,385		1,056,210
Payments	(537,254	)	(483,100	)
New loans and financing	837,819		550,966
Exchange variation	(2,873	)	17,834
Interest accrual	69,481		38,511
Interest paid	(57,038	)	(35,689	)
Addition of borrowing fees, net of amortization	(7,221	)	(347	)
Balance at the end of the year	1,447,299		1,144,385

Schedule of analysis of the loans and financings, by currency

	Current		Non-current		Total
	2017	2016	2017	2016	2017	2016
US Dollar	13,260	31,496	1,272,223	1,013,988	1,285,483	1,045,484
Real	27,471	28,170	134,235	66,954	161,706	95,124
Currency basket	110	2,935		842	110	3,777
	40,841	62,601	1,406,458	1,081,784	1,447,299	1,144,385

Schedule of analysis of the loans and financings, by index

	Current		Non-current		Total
	2017	2016	2017	2016	2017	2016
Fixed rate	11,192	6,466	1,038,459	346,997	1,049,651	353,463
LIBOR	610	24,037	230,573	662,743	231,183	686,780
TJLP	12,509	23,078	35,341	41,632	47,850	64,710
UMBNDES	3,211	6,042	5,496	9,087	8,707	15,129
CDI	9,811	504	62,632	3,822	72,443	4,326
BNDES Selic	3,508	2,474	33,957	17,503	37,465	19,977
	40,841	62,601	1,406,458	1,081,784	1,447,299	1,144,385

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Salaries and payroll charges (Tables)

12 Months Ended

Dec. 31, 2017

Salaries and payroll charges

Schedule of salaries and payroll charges

	2017	2016
Direct remuneration and social charges	21,357	18,655
Provision for profit sharing and other payable	58,441	51,367
	79,798	70,022

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Taxes payable (Tables)

12 Months Ended

Dec. 31, 2017

Taxes payable

Schedule of taxes payable

	2017	2016
Corporate taxes on income	24,108	18,145
Special mining lien and special mining tax	8,731	664
Withholding taxes	3,737	3,494
Value-added tax on sales and services	366	6,393
Social contribution on revenue	185	182
Social integration program	39	39
Other	3,943	931
	41,109	29,848

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Current and deferred taxes on income (Tables)

12 Months Ended

Dec. 31, 2017

Current and deferred taxes on income.

Schedule of reconciliation of taxes on income expenses

	2017		2016		2015
Profit before taxation	271,459		208,892		(178,257	)
Standard rate (i)	27.08	%	29.22	%	29.22	%
Taxes on income at standard rates	(73,511	)	(61,038	)	52,087
Share in the results of investees	16		(46	)	(75	)
Difference in tax rate for subsidiaries outside Luxembourg	(19,912	)	(11,425	)	4,138
Re-measurement of deferred tax - change in Peru tax rate (ii)	—		(41,588	)	—
Taxes on dividend received from foreign sudisdiary	(8,299	)	—		—
Taxes of prior years (iii)	(5,381	)	1,127		—
Difference arising on carrying non-current assets using a different base	12,144		2,458		(18,310	)
Other permanent (additions) exclusions, net	(11,251	)	12,129		939
Taxes on income	(106,194	)	(98,383	)	38,779
Current	(125,691	)	(75,282	)	(62,758	)
Deferred	19,497		(23,101	)	101,537
Taxes on income on the income statement	(106,194	)	(98,383	)	38,779

(i) The combined applicable income tax rate (including an unemployment fund contribution) was 29.22% for the fiscal year ending 2016. On December 14, 2016, the Luxembourg government approved bill of law 7020, in the 2017 tax reform bill. Among other changes included in the 2017 tax reform bill, the main change announced was the decrease of the income tax rate to 27.08% in 2017 and to 26.01% from 2018 onwards.

(ii) The Peruvian companies pay their taxes based on the general regime of taxation, which provides for a progressive decrease in the tax rate after the year 2015. Until 2014 the rate was 30%, while for 2015 and 2016 the rate was 28%, for 2017 and 2018 the rate was expected to be 27% and from 2019 onwards the rate was expected to be 26%. However, in December 2016, the tax rate changed to 29.5% applicable from January 1, 2017. The change impacted the deferred tax mainly over the purchase price allocation of NEXA PERU.

(iii) Income taxes paid or recovered in Austria by our subsidiary Votorantim GmbH which are related to prior years.

Schedule of analysis of deferred tax balances

	2017		2016
Tax credits on non-operating losses	104,100		102,555
Tax credits on temporary diferences
Exchange variation losses	79,430		84,536
Environmental liabilities	28,504		27,206
Asset retirement obligation	23,990		22,085
Tax, civil and labor provisions	15,666		16,904
Other provisions	12,481		13,792
Provision for profit sharing	6,521		6,322
Provision for inventory losses	4,395		5,202
Use of public assets	4,093		4,305
Provision for impairment of trade receivables	1,110		743
Other	5,028		1,863
Tax debits on temporary diferences
Adjustment to present value	(1,253	)	(1,269	)
Capitalized interest	(10,624	)	(7,184	)
Accelerated depreciation and adjustment of useful lives	(28,371	)	(20,748	)
Depreciation and amortization of fair value adjustment to PP&E and intangible assets	(344,531	)	(363,604	)
Other	(957	)	(12	)
	(100,418	)	(107,304	)
Net deferred tax assets related to the same legal entity	224,513		221,304
Net deferred tax liabilities related to the same legal entity	(324,931	)	(328,608	)
	(100,418	)	(107,304	)

Schedule of effects of deferred tax and taxes on profit or loss and other comprehensive income

	2017		2016
Balance at beginning of year	(107,304	)	(119,351	)
Effect on income for the period	19,497		(23,101	)
Effect on comprehensive income	(4,119	)	8,825
Exchange variation	(8,492	)	26,323
Balance at end of year	(100,418	)	(107,304	)

Schedule of tax effects relating to components of other comprehensive income (loss)

	2017				2016
	Before tax	(Charge) credit		After tax	Before tax		(Charge) credit	After tax
Operating cash flow hedge accounting	16,675	(4,119	)	12,556	(25,081	)	8,825	(16,256	)

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Provisions (Tables)

12 Months Ended

Dec. 31, 2017

Provisions

Schedule of Provisions

	2017														2016
					Judicial provision
	Asset Retirement Obligation (i)		Environmental Obligation (i)		Tax (ii)		Labor		Civil		Environmental		Total		Total
Balance at the beginning of the year	159,117		80,016		26,299		11,773		15,415		4,259		296,879		197,359
Present value adjustment	846		3,808										4,654		2,617
Additions	4,303		16,843		4,503		11,765		5,832		4,570		47,816		104,749
Reversals	—		(13,176	)	(14,569	)	(10,359	)	(63	)	(3,852	)	(42,019	)	(11,794	)
Judicial deposits, net of write-off	—		—		695		3,358		(778	)	—		3,275		(6,530	)
Write-off	(5,068	)	(3,847	)	(2,932	)	(3,703	)	(2,508	)	(608	)	(18,666	)	(7,678	)
Interest and indexation	—		—		4,429		3,818		341		234		8,822		4,926
Exchange variation	(2,520	)	191		150		(231	)	81		(38	)	(2,367	)	16,416
Companies excluded from the consolidation	(1,022	)	—		—		—		—		—		(1,022	)	—
Cost and interest revision	43,789		—		—		—		—		—		43,789		(3,186	)
Balance at the end of the year	199,445		83,835		18,575		16,421		18,320		4,565		341,161		296,879
Current	—		14,641		—		—		—		—		14,641		—
Non-current	199,445		69,194		18,575		16,421		18,320		4,565		326,520		296,879
	199,445		83,835		18,575		16,421		18,320		4,565		341,161		296,879

(i) In 2017, the Company conducted an update of its asset retirement obligations and potential environmental obligations. As a result of this study, which included the review of the timing of estimated disbursements, the Company recorded for Brazilian operations an additional asset retirement obligations in the amount of US$ 43,789, (US$ 38,541 related to cost revision and US$ 5,248 related to interest revision), and additional environmental obligations of US$ 16,843. For the new operation in Ambrosia, the Company recorded asset retirement obligations in the amount of US$ 4,227.

(ii) The reversal of the tax provision in the amount of US$ 14,569 during the year ended December 31, 2017 relates to a favorable judicial pronouncement for the exclusion of ICMS (tax levied over the sale of goods) from the calculation basis of PIS and COFINS (taxes levied over revenues).

Schedule of Provisions and judicial deposits

	2017					2016
	Judicial deposits		Provision	Net amount	Outstanding judicial deposits (i)	Judicial deposits		Provision	Net amount	Outstanding judicial deposits (i)
Tax	(2,318	)	20,893	18,575	3,130	(2,232	)	28,531	26,299	5,158
Labor	(4,765	)	21,186	16,421	7,408	(8,116	)	19,889	11,773	8,994
Civil	(758	)	19,078	18,320	23	(3	)	15,418	15,415	8
Environmental	—		4,565	4,565	388	—		4,259	4,259	—
	(7,841	)	65,722	57,881	10,949	(10,351	)	68,097	57,746	14,160

(i) The Company’s subsidiaries have deposited with the courts the above amounts in relation to proceedings classified by the Company, supported by its legal advisors as having a possible or remote possibility of loss, and which therefore, are not subject to provisions.

Schedule of litigation with likelihood of loss considered possible

	2017	2016
Tax	125,438	94,076
Labor	46,402	55,278
Civil	24,911	28,185
Environmental	133,851	130,549
	330,602	308,088

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Use of public Assets (Tables)

12 Months Ended

Dec. 31, 2017

Use of public assets.

Schedule of contracts for use of public assets

				2017				2016
Plants	Concession start date	Concession end date	Payment start date	Ownership interest		Intangible asset	Liabilities	Ownership interest		Intangible asset	Liabilities
Capim Branco I and Capim Branco II	Aug-01	Sep-39	Oct-07	13	%	800	3,085	13	%	890	3,357
Picada	May-01	Jun-36	Jul-06	100	%	5,502	19,535	100	%	5,856	20,776
Enercan - Campos Novos Energia	Apr-00	May-35	Jun-06	21	%	630	1,689	21	%	676	1,787
						6,932	24,309			7,422	25,920
Current							1,649				1,663
Non-current						6,932	22,660			7,422	24,257
						6,932	24,309			7,422	25,920

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Deferred revenue (Tables)

12 Months Ended

Dec. 31, 2017

Deferred revenue

Schedule of movements in deferred income

At January 2017	250,000
Revenue recognition for ore delivery	(36,299	)
Accretion for period	8,184
At December 2017	221,885
Current	31,296
Non-current	190,589
	221,885

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Equity (Tables)

12 Months Ended

Dec. 31, 2017

Equity.

Schedule of accumulated other comprehensive income (loss)

	Exchange
	variation on		Remeasurements with		Hedge
	investm ents abroad		retirement benefits		accounting		Total
At January 1, 2015	(45,297	)	2,792		444		(109,857	)
Currency translation of investees located abroad	(74,163	)	—		—		(74,163	)
Remeasurements of retirement benefits	—		535		—		535
Operating cash flow hedge accounting	—		—		5,832		5,832
At December 31, 2015	(119,460	)	3,327		6,276		(177,653	)
Currency translation of investees located abroad	30,373		—		—		30,373
Operating cash flow hedge accounting	—		—		(16,256	)	(16,256	)
At December 31, 2016	(89,087	)	3,327		(9,980	)	(163,536	)
Currency translation of investees located abroad	(10,742	)	—		—		(10,742	)
Operating cash flow hedge accounting	—		—		12,556		12,556
Achievement of remeasurements with retirement benefits	—		(3,327	)	—		(3,327	)
At December 31, 2017	(99,829	)	—		2,576		(165,049	)

Summary of earnings per share information

		(Restated)	(Restated)
	2017	2016	2015
Profit (loss) attributable to owners of the parent	126,885	93,167	(129,461	)
Weighted average number of outstanding common shares (thousands)	116,527	80,699	1,874
Earnings per share in US Dollars	1.09	1.15	(69.08	)

Summarised balance sheet on non-controlling interests

	NEXA CJM (i)		Pollarix S.A. (ii)
Summarised balance sheet	2017	2016	2017	2016
Current assets	1,105,182	1,159,112	6,717	26,128
Current liabilities	469,291	462,428	911	12,667
Current net assets	635,891	696,684	5,806	13,461
Non-current assets	2,852,410	3,070,147	110,246	161,595
Non-current liabilities	987,143	1,107,542	24,978	39,184
Non-current net assets	1,865,267	1,962,605	85,268	122,411
Net assets	2,501,158	2,659,289	91,074	135,872
Accumulated NCI	361,265	385,762	60,716	90,581

(i) Consolidated amounts, which includes NEXA CJM, NEXA PERU and NEXA ATACOCHA.

(ii) Consolidated amounts, which includes the energy generation assets Enercan, Capim Branco, Igarapava and Picada.

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Net revenue (Tables)

12 Months Ended

Dec. 31, 2017

Net revenue

Schedule of composition of net revenue

	2017		(Revised) 2016		(Revised) 2015
Gross revenue	2,709,236		2,193,867		2,072,439
Taxes on sales and returns	(259,752	)	(229,026	)	(207,256	)
Net revenue	2,449,484		1,964,841		1,865,183

Schedule of revenue by destination

	2017	(Revised) 2016	(Revised) 2015
Brazil	721,640	560,878	534,141
Peru	696,527	573,884	584,450
United States	158,060	156,634	99,884
Luxembourg	130,723	100,631	98,159
Switzerland	108,798	59,873	135,450
Argentina	79,463	45,050	14,904
Japan	69,565	36,005	32,994
Singapore	60,857	42,666	72,514
Colombia	47,734	39,137	42,007
Chile	38,101	67,546	52,865
Austria	37,270	22,982	18,731
Turkey	35,522	19,498	23,265
Germany	23,154	42,560	22,348
China	18,172	12,838	639
Italy	15,799	3,608	1,399
Korea	7,064	66,887	51,181
Other	201,035	114,164	80,252
	2,449,484	1,964,841	1,865,183

Schedule of revenue by currency

	2017	(Revised) 2016	(Revised) 2015
US Dollar	1,729,234	1,414,992	1,334,878
Real	717,032	547,537	529,218
Other	3,218	2,312	1,087
	2,449,484	1,964,841	1,865,183

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Expenses by nature (Tables)

12 Months Ended

Dec. 31, 2017

Expenses by nature

Schedule of expense by nature

	2017	(Revised) 2016	(Revised) 2015
Raw materials and consumables used	1,120,540	956,909	980,533
Employee benefit expenses	278,285	233,755	202,876
Depreciation and amortization	270,454	275,034	295,258
Freight costs	75,674	68,962	73,871
Services, miscellaneous	156,491	89,426	77,772
Other expenses	17,239	32,967	23,838
	1,918,683	1,657,053	1,654,148
Reconciliation
Cost of products sold	1,681,202	1,439,101	1,463,290
Selling expenses	89,239	90,647	84,559
General and administrative expenses	148,242	127,305	106,299
	1,918,683	1,657,053	1,654,148

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Employee benefit expenses (Tables)

12 Months Ended

Dec. 31, 2017

Employee benefit expenses

Schedule of employee benefit expenses

	2017	2016	2015
Direct remuneration	146,766	126,570	112,072
Social charges	76,677	66,863	60,761
Benefits	54,842	40,322	30,043
	278,285	233,755	202,876

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Other operating expenses, net (Tables)

12 Months Ended

Dec. 31, 2017

Other operating expenses, net

Schedule of other operating expenses, net

	2017		2016		2015
Environmental and asset retirement obligations	433		(68,605	)	—
Mining obligations	(11,498	)	(8,967	)	(8,953	)
Project expenses	(94,280	)	(48,562	)	(37,623	)
Net operating hedge loss	(18,785	)	(33,514	)	7,045
Judicial (provision) reversion	258		(15,331	)	—
Loss on sale of property, plant & equipment and intangibles assets	(694	)	(552	)	(3,446	)
Gain on sale of investment	4,588		408		—
Impairment of property, plant, equipment and intangibles	—		979		(8,574	)
Other operating expenses, net	(9,243	)	(3,675	)	4,446
	(129,221	)	(177,819	)	(47,105	)

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Net financial results (Tables)

12 Months Ended

Dec. 31, 2017

Net financial results

Schedule of net financial results

	2017		2016		2015
Finance income
Gains on financial investments	21,388		12,032		9,132
Interest on loans with related parties (Note 13)	1,012		7,165		5,702
Monetary adjustment of assets	1,881		1,507		1,147
Interest on financial assets	2,621		2,921		1,387
Other finance income	2,966		1,330		1,900
	29,868		24,955		19,268
Finance costs
Interest on loans and financing	(56,434	)	(36,059	)	(33,073	)
Interest on deferred revenue	(8,184	)	—		—
Monetary adjustment of provisions	(9,478	)	(9,595	)	(5,966	)
Charges on discounting of trade bills	(5,379	)	(6,105	)	(4,524	)
Present value adjustment	(9,180	)	(4,291	)	(3,341	)
Other finance costs	(17,514	)	(14,324	)	(14,721	)
	(106,169	)	(70,374	)	(61,625	)
Exchange and monetary variations, net (i)	(53,880	)	124,500		(299,574	)
Finance results, net	(130,181	)	79,081		(341,931	)

(i) Exchange variation is related mainly to debt of NEXA BR denominated in U.S. Dollar.

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Information by business segment and geographic area (Tables)

12 Months Ended

Dec. 31, 2017

Information by business segment and geographic area

Schedule of revenue by segments, composition of the revenue from external customer adjustments and cost of products sold adjustments

	2017
	Mining		Smelting		Elimination		Adjustment(i)		Total
Revenue from external customers	491,758		1,952,006		—		5,719		2,449,484
Intersegment (sales or transfer)	721,463		—		(721,463	)	—		—
Net revenue from products sold	1,213,221		1,952,006		(721,463	)	5,719		2,449,484
Cost of products sold	(581,029	)	(1,698,325	)	721,463		(123,311	)	(1,681,202	)
Gross Profit	632,192		253,681		—		(117,592	)	768,282

	(Revised) 2016
	Mining		Smelting		Elimination		Adjustment(i)		Total
Revenue from external customers	469,187		1,491,988		—		3,666		1,964,841
Intersegment (sales or transfer)	438,238		—		(438,238	)	—		—
Net revenue from products sold	907,425		1,491,988		(438,238	)	3,666		1,964,841
Cost of products sold	(513,135	)	(1,260,519	)	438,238		(103,685	)	(1,439,101	)
Gross Profit	394,290		231,469		—		(100,019	)	525,740

	(Revised) 2015
	Mining		Smelting		Elimination		Adjustment(i)		Total
Revenue from external customers	420,663		1,421,307		—		23,213		1,865,183
Intersegment (sales or transfer)	350,041		—		(350,041	)	—		—
Net revenue from products sold	770,704		1,421,307		(350,041	)	23,213		1,865,183
Cost of products sold	(532,097	)	(1,170,545	)	350,041		(110,689	)	(1,463,290	)
Gross Profit	238,607		250,762		—		(87,476	)	401,893

(i) The column “Adjustment” represents the residual component of revenue from external customers and cost of products sold either not pertaining to the Mining or Smelting segments, or, represents items that, because of their nature, are not being allocated to a specific segment, such as revenues sales of concentrate executed from the smelting segment, purchase price allocation amortization of the fair value adjustments which were recognized upon the acquisition of NEXA PERU, and other variable payments related to production performance results, fair value hedge from other operating expenses.

The table below shows the composition of the revenue from external customer adjustments according to their nature:

	2017		2016		2015
Sales of concentrate from smelting segment	5,740		7,153		17,945
VMZ Energy sales	—		—		8,354
Other	(21	)	(3,487	)	(3,086	)
Total Adjustment on revenue from external customer	5,719		3,666		23,213

The table below shows the composition of the cost of products sold adjustments according to their nature:

	2017		2016		2015
Cost of concentrate sold by smelting segment	(3,303	)	(2,405	)	(10,968	)
Cost of energy sold by VMZ	—		—		(4,788	)
Employee compensation - Production performance	(33,969	)	(31,602	)	(21,825	)
Amortization of purchase price allocation of Milpo	(77,585	)	(77,585	)	(77,672	)
Fair Value Hedge	(8,406	)	14,729		(6,230	)
Other	(48	)	(6,822	)	10,794
Total adjustment on cost of products sold	(123,311	)	(103,685	)	(110,689	)

Schedule of adjusted EBITDA by segments

	2017		2016		2015
Mining	521,544		336,796		221,791
Smelting	152,739		70,528		259,768
Segment Adjusted EBITDA	674,283		407,324		481,559
Extraordinary items:
Gains on sales of investments	4,588		408		—
Impairment of other assets	(73	)	(308	)	—
(Reversal) Impairment - property, plant, equipment	—		979		(8,574	)
Other (i)	(6,764	)	(3,400	)	(13,797	)
Results of investees	60		(158	)	(256	)
Depreciation, amortization and depletion	(270,454	)	(275,034	)	(295,258	)
Net financial results	(130,181	)	79,081		(341,931	)
Taxes on income	(106,194	)	(98,383	)	38,779
Descontinued operations	—		—		(318	)
Profit (loss) for the year	165,265		110,509		(139,796	)

(i) The line item “Other” represents the residual component of Adjusted EBITDA either not pertaining to the Mining or Smelting segments, or, represents items that, because of their nature, are not being allocated to a specific segment.

Schedule of information by geographic area

	2017
	Net revenue from products sold	Cost of products sold		Gross profit
Brazil	1,003,804	(670,964	)	332,840
Peru	1,445,680	(1,010,238	)	435,442
Total	2,449,484	(1,681,202	)	768,282

	(Revised) 2016
	Net revenue from products sold	Cost of products sold		Gross profit
Brazil	727,462	(484,851	)	242,611
Peru	1,237,379	(954,250	)	283,129
Total	1,964,841	(1,439,101	)	525,740

	(Revised) 2015
	Net revenue from products sold	Cost of products sold		Gross profit
Brazil	665,573	(460,284	)	205,289
Peru	1,199,610	(1,003,006	)	196,604
Total	1,865,183	(1,463,290	)	401,893

XML

Insurance coverage (Tables)

12 Months Ended

Dec. 31, 2017

Insurance coverage

Schedule of operational insurance coverage

The operational insurance coverage as at December 31, 2017 was as follows:

Assets	Type of coverage	Insured amount
Facilities, equipment and	Property damage	3,234,169
products in inventory	Loss of profits	778,735

XML

General information (Details) R$ in Thousands, $ in Thousands	1 Months Ended		12 Months Ended
	Jun. 30, 2017 BRL (R$)	Jun. 30, 2017 USD ($)	Dec. 31, 2017 USD ($) location Asset	Feb. 28, 2017 BRL (R$)	Feb. 28, 2017 USD ($)	Dec. 31, 2016 USD ($)
General information
Trade accounts receivable			$ 3,775			$ 6,389
Votorantim S.A.
General information
Percentage of equity interest held by the controlling shareholder (as a percent)			64.25%
Trade accounts receivable			$ 8			75
Companhia Brasileira de Aluminio
General information
Trade accounts receivable			$ 1,843			$ 3,847
Companhia Brasileira de Aluminio | NEXA BR
General information
Liquidation of dues, export prepayments	R$ 1,215,489	$ 367,417
Liquidation of dues, other payables		10,244
Transfer of property, plant and equipment		2,848
Transfer of intangibles		705
Amount of participating shares transferred		$ 374,108
Companhia Brasileira de Aluminio | NEXA BR
General information
Net export prepayments					$ 389,471
Trade accounts receivable				R$ 1,215,489	389,471
Companhia Brasileira de Aluminio | NEXA BR | Votorantim GmbH
General information
Export Prepayments					290,000
Companhia Brasileira de Aluminio | NEXA BR | Nexa Resources S.A.
General information
Export Prepayments					$ 100,000
Companhia Brasileira de Aluminio | Votorantim Investimentos Latino-Americanos S.A. - "VILA" | NEXA BR
General information
Percentage of participating shares transferred	25.80%	25.80%
Mining | Peru and Brazil
General information
Number of Mines | location			5
Smelting | Peru and Brazil
General information
Number of assets held | Asset			3
Smelting | Peru
General information
Number of assets held | Asset			1
Smelting | Brazil
General information
Number of assets held | Asset			2

XML

General information - Bond Issuance and Energy Assets compensation payment (Details) R$ in Thousands, $ in Thousands						1 Months Ended			12 Months Ended
	Jun. 30, 2017 USD ($)	May 31, 2017 BRL (R$)	May 31, 2017 USD ($)	May 19, 2017 BRL (R$)	May 19, 2017 USD ($)	Oct. 31, 2017 USD ($)	Sep. 30, 2017 USD ($)	Jun. 30, 2017 USD ($)	Dec. 31, 2017 USD ($)	Dec. 31, 2016 USD ($)	Dec. 31, 2015 USD ($)	May 04, 2017 USD ($)
General information
Issuance of new shares									$ 306,431	$ 170,070	$ 84
Energy asset compensation paid in cash									55,380		$ (52,686)
Reimbursement of share premium						$ 150,000	$ 140,000	$ 140,000	430,000	69,931
Reversion of Put Option									173,734
Share premium
General information
Issuance of new shares									285,931	59,159
Conversion of share capital into share premium						$ 428,596	$ 300,000	$ 200,000	928,596	350,000
Reimbursement of share premium									$ 430,000	$ 69,931
Votorantim S.A.
General information
Reversion of Put Option	$ 173,734
Votorantim Investimentos Latino-Americanos S.A. - "VILA"
General information
Issuance of new shares				R$ 129,187	$ 39,827
Votorantim Investimentos Latino-Americanos S.A. - "VILA" | Votorantim S.A.
General information
Amount of cash transferred for reduction of capital		R$ 129,187	$ 39,827
NEXA BR | Votorantim S.A.
General information
Amount of cash transferred for reduction of capital		R$ 50,450	$ 15,553
Ten-year bond
General information
Principal amount												$ 700,000
Interest rate (as a percent)												5.375%

XML

General information - Energy Assets (Details) R$ in Thousands, $ in Thousands					1 Months Ended				12 Months Ended	15 Months Ended
	Dec. 31, 2017	Jun. 30, 2017 BRL (R$) multiple	Jun. 30, 2017 USD ($)	Dec. 31, 2016	Oct. 31, 2017 BRL (R$)	Oct. 31, 2017 USD ($)	Jun. 30, 2017 BRL (R$) multiple	Jun. 30, 2017 USD ($)	Dec. 31, 2017 USD ($)	Jun. 30, 2017 USD ($)	Jun. 30, 2017 USD ($) multiple
Disclosure of General Information [Line Items]
Payment for purchase of shares									$ 81,615
Gain (loss) on energy asset transaction										$ 0
VSA and its Subsidiaries
Disclosure of General Information [Line Items]
Preferred dividends per share payable, multiple | multiple		1.25					1.25				1.25
Pollarix S. A.
Disclosure of General Information [Line Items]
Proportion of share capital held on outstanding share capital		33.33%	33.33%
Percentage of ordinary shares acquired		100.00%					100.00%				100.00%
Ownership interest (as a percent)	33.33%			33.33%
Percentage of participation by noncontrolling interest in subsidiary	67.00%
Pollarix S. A. | VSA and its Subsidiaries
Disclosure of General Information [Line Items]
Proportion of share capital held on outstanding share capital		66.67%	66.67%
Percentage of preferred shares non-controlling rights held		100.00%	100.00%
Pollarix S. A. | Companhia Brasileira de Aluminio
Disclosure of General Information [Line Items]
Amount payable for purchase of shares		R$ 270,000					R$ 270,000				$ 81,620
Payment for purchase of shares					R$ 73,000	$ 22,277	R$ 197,000	$ 59,549
Pollarix S. A. | Campos Novos Energia S.A. - "Enercan"
Disclosure of General Information [Line Items]
Percentage of holding										20.98%
NEXA BR
Disclosure of General Information [Line Items]
Ownership interest (as a percent)	100.00%	100.00%	100.00%	100.00%
Percentage of participation by noncontrolling interest in subsidiary	0.00%
NEXA BR | VSA and its Subsidiaries
Disclosure of General Information [Line Items]
Amount of cash transferred for reduction of capital		R$ 290,000	$ 87,666
Votorantim Investimentos Latino-Americanos S.A. - "VILA"
Disclosure of General Information [Line Items]
Ownership interest (as a percent)	100.00%			100.00%						100.00%
Percentage of participation by noncontrolling interest in subsidiary	0.00%

XML

General information - Capital increase and IPO (Details) $ / shares in Units, R$ in Thousands, $ in Thousands					1 Months Ended		4 Months Ended	12 Months Ended
	Oct. 31, 2017 USD ($) $ / shares shares	Oct. 27, 2017 USD ($)	Oct. 16, 2017 USD ($)	Sep. 19, 2017 USD ($)	Oct. 31, 2017 USD ($) $ / shares shares	Jul. 31, 2017 USD ($)	Oct. 31, 2017 USD ($) $ / shares shares	Dec. 31, 2017 USD ($)	Dec. 31, 2016 USD ($)	Dec. 31, 2015 USD ($)	Oct. 27, 2017 BRL (R$) shares	Oct. 27, 2017 USD ($) shares
Disclosure of General Information [Line Items]
Dividend payment								$ 58,854	$ 10,355	$ 66,197
Number of shares in initial public offering | shares	35,650,000				35,650,000		35,650,000
Issue price per share | $ / shares	$ 16.00				$ 16.00		$ 16.00
Issue of equity								306,431	170,070	84
Capital
Disclosure of General Information [Line Items]
Issue of equity	$ 20,500							20,500	110,911	84
Share premium
Disclosure of General Information [Line Items]
Issue of equity								285,931	59,159
Share premium constitution, gross	307,500
Share issue related cost	$ 21,569
NEXA BR
Disclosure of General Information [Line Items]
Increase in capital					$ 137,176	$ 63,216
Increase (decrease) through changes in ownership interests in subsidiaries that do not result in loss of control, equity								7,911		52,686
NEXA PERU
Disclosure of General Information [Line Items]
Dividend payment				$ 335,001
Dividends paid to non-controlling interests			$ 55,073
Increase (decrease) through changes in ownership interests in subsidiaries that do not result in loss of control, equity									$ (170,663)	$ (7,889)
Pollarix S. A.
Disclosure of General Information [Line Items]
Reduction in share capital through cancellation of shares											R$ 189,000	$ 57,134
Number of ordinary shares cancelled | shares											81,818,181	81,818,181
Number of preferred shares cancelled | shares											163,636,364	163,636,364
Increase (decrease) through changes in ownership interests in subsidiaries that do not result in loss of control, equity		$ (38,280)						$ (38,280)
Votorantim S.A.
Disclosure of General Information [Line Items]
Number of shares sold by controlling shareholder | shares	15,150,000
Number of shares related to exercise of over-allotment option | shares	4,650,000
Votorantim S.A. | NEXA BR
Disclosure of General Information [Line Items]
Amount paid by controlling shareholder							$ 19,176

XML

Basis of preparation of the consolidated financial statements (Details)				15 Months Ended
	Dec. 31, 2017	Jun. 30, 2017	Dec. 31, 2016	Jun. 30, 2017
Campos Novos Energia S.A. - "Enercan"
Significant investment in subsidiary
Percentage of Capital	20.98%		20.98%
Capim Branco Energia
Significant investment in subsidiary
Percentage of Capital	12.63%		12.63%
Cia . Minera Gaico S.A.
Significant investment in subsidiary
Percentage of Capital	93.40%		93.40%
Cia. Magistral S.A.C
Significant investment in subsidiary
Percentage of Capital	100.00%
Cia. Minera Dona Isabel Ltda.
Significant investment in subsidiary
Percentage of Capital	100.00%		100.00%
Cia. Minera Shalipayco S.A.C
Significant investment in subsidiary
Percentage of Capital	75.00%		75.00%
Nexa Resources Atacocha S.A.A. - "NEXA ATACOCHA" (formely Compania Minera Atacocha S.A.A.)
Significant investment in subsidiary
Percentage of Capital	66.62%		66.62%
NEXA PERU
Significant investment in subsidiary
Percentage of Capital	80.23%		80.23%
Consorcio UHE Igarapava
Significant investment in subsidiary
Percentage of Capital	23.93%		23.93%
InPac Holding Limited
Significant investment in subsidiary
Percentage of Capital	100.00%		100.00%
Inversiones Garza Azul S.A.C
Significant investment in subsidiary
Percentage of Capital	100.00%		100.00%
L.D.O.S.P.E. Empreendimentos e Participaes Ltda.
Significant investment in subsidiary
Percentage of Capital	100.00%
L.D.Q.S.P.E. Empreendimentos e Participaes Ltda.
Significant investment in subsidiary
Percentage of Capital	100.00%
L.D.R.S.P.E. Empreendimentos e Participaes Ltda.
Significant investment in subsidiary
Percentage of Capital	100.00%
Nexa Resources El Porvenir S.A.C. (formely Milpo Andina Peru S.A.C.)
Significant investment in subsidiary
Percentage of Capital	99.99%		99.99%
Nexa Resources UK Ltd. - "NEXA UK" (formely Milpo UK Limited)
Significant investment in subsidiary
Percentage of Capital	100.00%		100.00%
Minera Bongara S.A.
Significant investment in subsidiary
Percentage of Capital	61.00%		61.00%
Minera Cerro Colorado S.A.C
Significant investment in subsidiary
Percentage of Capital	99.99%		99.00%
Minera Chambara S.A.C
Significant investment in subsidiary
Percentage of Capital	15.00%		15.00%
Minera Pampa de Cobre S.A.C
Significant investment in subsidiary
Percentage of Capital	99.99%		99.00%
Minera Rayrock Ltda.
Significant investment in subsidiary
Percentage of Capital			84.08%
Mineracao Dardanelos Ltda.
Significant investment in subsidiary
Percentage of Capital	70.00%		70.00%
Mineracao Santa Maria Ltda.
Significant investment in subsidiary
Percentage of Capital	99.99%		99.99%
Otavi Mining Investments (Pty) Ltd.
Significant investment in subsidiary
Percentage of Capital	100.00%		100.00%
Otjitombo Mining Proprietary Ltd.
Significant investment in subsidiary
Percentage of Capital	100.00%		100.00%
Pollarix S. A.
Significant investment in subsidiary
Percentage of Capital	33.33%		33.33%
Rayrock Antofagasta S.A.C
Significant investment in subsidiary
Percentage of Capital	99.99%		100.00%
SMRL CMA n 54
Significant investment in subsidiary
Percentage of Capital	100.00%		100.00%
SMRL Ltda. Pepita 1
Significant investment in subsidiary
Percentage of Capital	57.50%		57.50%
Votorantim Andina S.A. - "VASA"
Significant investment in subsidiary
Percentage of Capital	99.99%		99.99%
Votorantim GmbH
Significant investment in subsidiary
Percentage of Capital	100.00%		100.00%
Votorantim Investimentos Latino-Americanos S.A. - "VILA"
Significant investment in subsidiary
Percentage of Capital	100.00%		100.00%	100.00%
Votorantim Metais Argentina S.A.
Significant investment in subsidiary
Percentage of Capital			90.00%
Votorantim Metais Bolivia S.R.L.
Significant investment in subsidiary
Percentage of Capital			76.61%
Nexa Resources Cajamarquilla S.A. - "NEXA CJM" (formely Votorantim Metais Cajamarquilla S.A. - "CJM")
Significant investment in subsidiary
Percentage of Capital	99.99%		99.99%
NEXA BR
Significant investment in subsidiary
Percentage of Capital	100.00%	100.00%	100.00%
Votorantim Metals Cananda Inc.
Significant investment in subsidiary
Percentage of Capital	100.00%		100.00%
Votorantim Metals Namibia Ltd.
Significant investment in subsidiary
Percentage of Capital	100.00%		100.00%
Votorantim US. Inc.
Significant investment in subsidiary
Percentage of Capital	100.00%		100.00%

XML

Basis of preparation of the consolidated financial statements - Revision of Financial Statements - Income Statement (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Disclosure of revision of income statement
Net revenue from products sold	$ 2,449,484	$ 1,964,841	$ 1,865,183
Cost of products sold	(1,681,202)	(1,439,101)	(1,463,290)
Gross profit	768,282	525,740	401,893
Gross Revenue	2,709,236	2,193,867	2,072,439
Taxes on sales and returns	(259,752)	(229,026)	(207,256)
Original
Disclosure of revision of income statement
Net revenue from products sold		1,912,813	1,824,840
Cost of products sold		(1,387,073)	(1,422,947)
Gross profit		525,740	401,893
Gross Revenue		2,193,867	2,072,439
Taxes on sales and returns		(281,054)	(247,599)
Adjustment
Disclosure of revision of income statement
Net revenue from products sold		52,028	40,343
Cost of products sold		(52,028)	(40,343)
Taxes on sales and returns		52,028	40,343
US Dollar
Disclosure of revision of income statement
Net revenue from products sold	1,729,234	1,414,992	1,334,878
US Dollar | Original
Disclosure of revision of income statement
Net revenue from products sold		1,362,964	1,294,535
US Dollar | Adjustment
Disclosure of revision of income statement
Net revenue from products sold		52,028	40,343
BRL
Disclosure of revision of income statement
Net revenue from products sold	717,032	547,537	529,218
BRL | Original
Disclosure of revision of income statement
Net revenue from products sold		547,537	529,218
Other
Disclosure of revision of income statement
Net revenue from products sold	3,218	2,312	1,087
Other | Original
Disclosure of revision of income statement
Net revenue from products sold		2,312	1,087
Peru
Disclosure of revision of income statement
Net revenue from products sold	696,527	573,884	584,450
Peru | Original
Disclosure of revision of income statement
Net revenue from products sold		521,856	544,107
Peru | Adjustment
Disclosure of revision of income statement
Net revenue from products sold		52,028	40,343
Brazil
Disclosure of revision of income statement
Net revenue from products sold	721,640	560,878	534,141
Brazil | Original
Disclosure of revision of income statement
Net revenue from products sold		560,878	534,141
United States
Disclosure of revision of income statement
Net revenue from products sold	158,060	156,634	99,884
United States | Original
Disclosure of revision of income statement
Net revenue from products sold		156,634	99,884
Luxembourg
Disclosure of revision of income statement
Net revenue from products sold	130,723	100,631	98,159
Luxembourg | Original
Disclosure of revision of income statement
Net revenue from products sold		100,631	98,159
Korea
Disclosure of revision of income statement
Net revenue from products sold	7,064	66,887	51,181
Korea | Original
Disclosure of revision of income statement
Net revenue from products sold		66,887	51,181
Switzerland
Disclosure of revision of income statement
Net revenue from products sold	108,798	59,873	135,450
Switzerland | Original
Disclosure of revision of income statement
Net revenue from products sold		59,873	135,450
Chile
Disclosure of revision of income statement
Net revenue from products sold	38,101	67,546	52,865
Chile | Original
Disclosure of revision of income statement
Net revenue from products sold		67,546	52,865
Singapore
Disclosure of revision of income statement
Net revenue from products sold	60,857	42,666	72,514
Singapore | Original
Disclosure of revision of income statement
Net revenue from products sold		42,666	72,514
Germany
Disclosure of revision of income statement
Net revenue from products sold	23,154	42,560	22,348
Germany | Original
Disclosure of revision of income statement
Net revenue from products sold		42,560	22,348
Colombia
Disclosure of revision of income statement
Net revenue from products sold	47,734	39,137	42,007
Colombia | Original
Disclosure of revision of income statement
Net revenue from products sold		39,137	42,007
Japan
Disclosure of revision of income statement
Net revenue from products sold	69,565	36,005	32,994
Japan | Original
Disclosure of revision of income statement
Net revenue from products sold		36,005	32,994
Austria
Disclosure of revision of income statement
Net revenue from products sold	37,270	22,982	18,731
Austria | Original
Disclosure of revision of income statement
Net revenue from products sold		22,982	18,731
Turkey
Disclosure of revision of income statement
Net revenue from products sold	35,522	19,498	23,265
Turkey | Original
Disclosure of revision of income statement
Net revenue from products sold		19,498	23,265
China
Disclosure of revision of income statement
Net revenue from products sold	18,172	12,838	639
China | Original
Disclosure of revision of income statement
Net revenue from products sold		12,838	639
Italy
Disclosure of revision of income statement
Net revenue from products sold	$ 15,799	3,608	1,399
Italy | Original
Disclosure of revision of income statement
Net revenue from products sold		3,608	1,399
Other Countries
Disclosure of revision of income statement
Net revenue from products sold		159,214	95,156
Other Countries | Original
Disclosure of revision of income statement
Net revenue from products sold		$ 159,214	$ 95,156

XML

Basis of preparation of the consolidated financial statements - Revision - Expenses by nature (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Expenses by nature
Raw materials and consumables used	$ 1,120,540	$ 956,909	$ 980,533
Employee benefit expenses	278,285	233,755	202,876
Depreciation and amortization	270,454	275,034	295,258
Freight costs	75,674	68,962	73,871
Services, miscellaneous	156,491	89,426	77,772
Other expenses	17,239	32,967	23,838
Expenses by nature	1,918,683	1,657,053	1,654,148
Reconciliation
Cost of products sold	1,681,202	1,439,101	1,463,290
Selling expenses	89,239	90,647	84,559
General and administrative expenses	148,242	127,305	106,299
Expenses by nature	$ 1,918,683	1,657,053	1,654,148
Original
Expenses by nature
Raw materials and consumables used		904,881	940,190
Employee benefit expenses		233,755	202,876
Depreciation and amortization		275,034	295,258
Freight costs		68,962	73,871
Services, miscellaneous		89,426	77,772
Other expenses		32,967	23,838
Expenses by nature		1,605,025	1,613,805
Reconciliation
Cost of products sold		1,387,073	1,422,947
Selling expenses		90,647	84,559
General and administrative expenses		127,305	106,299
Expenses by nature		1,605,025	1,613,805
Adjustment
Expenses by nature
Raw materials and consumables used		52,028	40,343
Expenses by nature		52,028	40,343
Reconciliation
Cost of products sold		52,028	40,343
Expenses by nature		$ 52,028	$ 40,343

XML

Basis of preparation of the consolidated financial statements - Revision - Segments (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Disclosure of revision of segment information
Net revenue	$ 2,449,484	$ 1,964,841	$ 1,865,183
Cost of products sold	1,681,202	1,439,101	1,463,290
Gross profit	768,282	525,740	401,893
Original
Disclosure of revision of segment information
Net revenue		1,912,813	1,824,840
Cost of products sold		1,387,073	1,422,947
Gross profit		525,740	401,893
Adjustment
Disclosure of revision of segment information
Net revenue		52,028	40,343
Cost of products sold		52,028	40,343
Elimination
Disclosure of revision of segment information
Net revenue	(721,463)	(438,238)	(350,041)
Cost of products sold	(721,463)	(438,238)	(350,041)
Elimination | Original
Disclosure of revision of segment information
Net revenue		(490,266)	(390,384)
Cost of products sold		(490,266)	(390,384)
Adjustments
Disclosure of revision of segment information
Net revenue	5,719	3,666	23,213
Cost of products sold	123,311	103,685	110,689
Gross profit	(117,592)	(100,019)	(87,476)
Adjustments | Original
Disclosure of revision of segment information
Net revenue		3,666	23,213
Cost of products sold		103,685	110,689
Gross profit		(100,019)	(87,476)
Mining
Disclosure of revision of segment information
Net revenue	491,758	469,187	420,663
Mining | Original
Disclosure of revision of segment information
Net revenue		417,159	380,320
Mining | Operating segment
Disclosure of revision of segment information
Net revenue	1,213,221	907,425	770,704
Cost of products sold	581,029	513,135	532,097
Gross profit	632,192	394,290	238,607
Mining | Operating segment | Original
Disclosure of revision of segment information
Net revenue		907,425	770,704
Cost of products sold		513,135	532,097
Gross profit		394,290	238,607
Mining | Elimination
Disclosure of revision of segment information
Net revenue	(721,463)	(438,238)	(350,041)
Mining | Elimination | Original
Disclosure of revision of segment information
Net revenue		(490,266)	(390,384)
Smelting
Disclosure of revision of segment information
Net revenue	1,952,006	1,491,988	1,421,307
Smelting | Original
Disclosure of revision of segment information
Net revenue		1,491,988	1,421,307
Smelting | Operating segment
Disclosure of revision of segment information
Net revenue	1,952,006	1,491,988	1,421,307
Cost of products sold	1,698,325	1,260,519	1,170,545
Gross profit	$ 253,681	231,469	250,762
Smelting | Operating segment | Original
Disclosure of revision of segment information
Net revenue		1,491,988	1,421,307
Cost of products sold		1,260,519	1,170,545
Gross profit		231,469	250,762
Brazil
Disclosure of revision of segment information
Net revenue		714,946	665,573
Cost of products sold		473,006	460,284
Gross profit		241,940	205,289
Brazil | Original
Disclosure of revision of segment information
Net revenue		714,946	665,573
Cost of products sold		473,006	460,284
Gross profit		241,940	205,289
Peru
Disclosure of revision of segment information
Net revenue		1,230,382	1,199,607
Cost of products sold		948,967	1,003,006
Gross profit		281,415	196,601
Peru | Original
Disclosure of revision of segment information
Net revenue		1,178,354	1,159,264
Cost of products sold		896,940	962,663
Gross profit		281,414	196,601
Holding
Disclosure of revision of segment information
Net revenue		19,513	3
Cost of products sold		17,128
Gross profit		2,385	3
Holding | Original
Disclosure of revision of segment information
Net revenue		19,513	3
Cost of products sold		17,127
Gross profit		$ 2,386	$ 3

XML

Basis of preparation of the consolidated financial statements - Revision - Earnings per share (Details) - $ / shares	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Disclosure of revision of earnings per share
Earnings per share in US Dollars	$ 1.09	$ 1.15	$ (69.08)
Original
Disclosure of revision of earnings per share
Earnings per share in US Dollars		1.37	(74.60)
Adjustment
Disclosure of revision of earnings per share
Earnings per share in US Dollars		$ (0.22)	$ 5.52

XML

Financial risk management - Foreign Exchange Risk (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Financial risk Management
Trade accounts receivable	$ 182,713	$ 120,062
Total assets	5,961,524	6,160,553
Loans and financing	1,447,299	1,144,385	$ 1,056,210
Trade payables	329,814	282,241
Total liabilities	3,052,621	2,836,237
Foreign currencies
Financial risk Management
Cash, cash equivalents and financial investments	229,876	154,693
Derivative financial instruments	4,280	10,005
Trade accounts receivable	66,834	45,194
Total assets	300,990	209,892
Loans and financing	161,706	95,124
Derivative financial instruments	3,634
Trade payables	78,286	61,075
Total liabilities	243,626	156,199
Net assets	$ 57,364	$ 53,693

XML

Financial risk management - Credit Risk (Details)	12 Months Ended
	Dec. 31, 2017 Agency item
Disclosure of external credit agencies
Number of ratings from international rating agencies required for making deposit | item	2
Peru
Disclosure of external credit agencies
Number of agencies that have given BBB minus rating required if only global rating available | Agency	1

XML

Financial risk management - Liquidity Risk - Estimated future cash flow (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Maturity analysis of financial instruments
Financial liabilities, undiscounted cash flows	$ 2,957,719	$ 2,359,966
Minimum
Maturity analysis of financial instruments
Cash flow projection period for liquidity measurement and monitoring	12 months
Loans and financing
Maturity analysis of financial instruments
Non-derivative financial liabilities, undiscounted cash flows	$ 1,941,018	1,350,827
Derivative financial instruments
Maturity analysis of financial instruments
Derivative financial liabilities, undiscounted cash flows	15,037	37,458
Trade payables
Maturity analysis of financial instruments
Non-derivative financial liabilities, undiscounted cash flows	329,814	282,241
Confirming payable
Maturity analysis of financial instruments
Non-derivative financial liabilities, undiscounted cash flows	111,024	102,287
Salaries and payroll charges
Maturity analysis of financial instruments
Non-derivative financial liabilities, undiscounted cash flows	79,798	70,022
Dividends payable
Maturity analysis of financial instruments
Non-derivative financial liabilities, undiscounted cash flows	4,138	7,185
Related parties
Maturity analysis of financial instruments
Non-derivative financial liabilities, undiscounted cash flows	89,924	230,513
Asset retirement obligation
Maturity analysis of financial instruments
Non-derivative financial liabilities, undiscounted cash flows	331,929	218,079
Use of public asset
Maturity analysis of financial instruments
Non-derivative financial liabilities, undiscounted cash flows	55,037	61,354
2018
Maturity analysis of financial instruments
Financial liabilities, undiscounted cash flows	736,607	861,198
2018 | Loans and financing
Maturity analysis of financial instruments
Non-derivative financial liabilities, undiscounted cash flows	102,294	104,191
2018 | Derivative financial instruments
Maturity analysis of financial instruments
Derivative financial liabilities, undiscounted cash flows	12,588	37,458
2018 | Trade payables
Maturity analysis of financial instruments
Non-derivative financial liabilities, undiscounted cash flows	329,814	282,241
2018 | Confirming payable
Maturity analysis of financial instruments
Non-derivative financial liabilities, undiscounted cash flows	111,024	102,287
2018 | Salaries and payroll charges
Maturity analysis of financial instruments
Non-derivative financial liabilities, undiscounted cash flows	79,798	70,022
2018 | Dividends payable
Maturity analysis of financial instruments
Non-derivative financial liabilities, undiscounted cash flows	4,138	7,185
2018 | Related parties
Maturity analysis of financial instruments
Non-derivative financial liabilities, undiscounted cash flows	87,686	222,917
2018 | Asset retirement obligation
Maturity analysis of financial instruments
Non-derivative financial liabilities, undiscounted cash flows	7,526	33,143
2018 | Use of public asset
Maturity analysis of financial instruments
Non-derivative financial liabilities, undiscounted cash flows	1,740	1,754
Between 1 and 3 years
Maturity analysis of financial instruments
Financial liabilities, undiscounted cash flows	435,195	475,293
Between 1 and 3 years | Loans and financing
Maturity analysis of financial instruments
Non-derivative financial liabilities, undiscounted cash flows	373,324	438,569
Between 1 and 3 years | Derivative financial instruments
Maturity analysis of financial instruments
Derivative financial liabilities, undiscounted cash flows	2,449
Between 1 and 3 years | Related parties
Maturity analysis of financial instruments
Non-derivative financial liabilities, undiscounted cash flows	2,238	7,596
Between 1 and 3 years | Asset retirement obligation
Maturity analysis of financial instruments
Non-derivative financial liabilities, undiscounted cash flows	53,429	25,296
Between 1 and 3 years | Use of public asset
Maturity analysis of financial instruments
Non-derivative financial liabilities, undiscounted cash flows	3,755	3,832
Between 3 and 5 years
Maturity analysis of financial instruments
Financial liabilities, undiscounted cash flows	274,346	472,719
Between 3 and 5 years | Loans and financing
Maturity analysis of financial instruments
Non-derivative financial liabilities, undiscounted cash flows	236,927	432,587
Between 3 and 5 years | Asset retirement obligation
Maturity analysis of financial instruments
Non-derivative financial liabilities, undiscounted cash flows	33,186	35,813
Between 3 and 5 years | Use of public asset
Maturity analysis of financial instruments
Non-derivative financial liabilities, undiscounted cash flows	4,233	4,319
Over 5 years
Maturity analysis of financial instruments
Financial liabilities, undiscounted cash flows	1,511,571	550,756
Over 5 years | Loans and financing
Maturity analysis of financial instruments
Non-derivative financial liabilities, undiscounted cash flows	1,228,474	375,480
Over 5 years | Asset retirement obligation
Maturity analysis of financial instruments
Non-derivative financial liabilities, undiscounted cash flows	237,788	123,827
Over 5 years | Use of public asset
Maturity analysis of financial instruments
Non-derivative financial liabilities, undiscounted cash flows	$ 45,309	$ 51,449

XML

Financial risk management - Net debt ratio (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Net debt ratio
Loans and financing	$ 1,447,299	$ 1,144,385	$ 1,056,210
Cash and cash equivalents	(1,019,037)	(915,576)	(621,415)	$ (750,679)
Derivative financial instruments	3,260	16,718	(10,105)
Financial investments	(206,547)	(119,498)	(57,856)
Net debt	224,975	126,029	366,834
Profit for the year	165,265	110,509	(139,796)
Plus (less):
Results of investees	(60)	158	256
Results of investees - Discontinued operations			318
Depreciation and amortization	270,454	275,034	295,258
Net financial results	130,181	(79,081)	341,931
Taxes on income	106,194	98,383	(38,779)
EBITDA	672,034	405,003	459,188
Exceptional items
Gains on sales of investments	(4,588)	(408)
Impairment of other assets	73	308
(Reversal) Impairment - property, plant, equipment		(979)	8,574
Adjusted EBITDA	$ 667,519	$ 403,924	$ 467,762
Gearing ratio	0.34%	0.31%	0.78%

XML

Financial risk management - Net debt reconciliation (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2017 USD ($)
Net debt reconciliation
Net debt as at the beginning of the period	$ 126,029
Cash flows	106,238
Foreign Exchange Adjustments	(2,921)
Other non-cash movements	(4,371)
Net debt as at the end of the period	224,975
Cash and cash equivalents
Net debt reconciliation
Net debt as at the beginning of the period	(915,576)
Cash flows	(103,413)
Foreign Exchange Adjustments	(48)
Net debt as at the end of the period	(1,019,037)
Financial investments
Net debt reconciliation
Net debt as at the beginning of the period	(119,498)
Cash flows	(65,661)
Other non-cash movements	(21,388)
Net debt as at the end of the period	(206,547)
Derivative financial instruments
Net debt reconciliation
Net debt as at the beginning of the period	16,718
Cash flows	39,006
Other non-cash movements	(52,464)
Net debt as at the end of the period	3,260
Loans and financing
Net debt reconciliation
Net debt as at the beginning of the period	1,144,385
Cash flows	236,306
Foreign Exchange Adjustments	(2,873)
Other non-cash movements	69,481
Net debt as at the end of the period	$ 1,447,299

XML

Financial risk management - Financial assets and liabilities at fair value (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Financial risk Management
Transfer of assets from level 1 to level 2	$ 0
Transferor assets from level 2 to level 1	0
Transfer of liabilities from level 1 to level 2	0
Transfer of liabilities from level 2 to level 1	0
Loans and financing and derivative financial liabilities
Financial risk Management
Financial liabilities, at fair value	1,550,169	$ 1,188,343
Loans and financing
Financial risk Management
Financial liabilities, at fair value	1,535,132	1,150,885
Derivative financial instruments
Financial risk Management
Financial liabilities, at fair value	15,037	37,458
Level 1 | Loans and financing and derivative financial liabilities
Financial risk Management
Financial liabilities, at fair value	1,120,901	342,156
Level 1 | Loans and financing
Financial risk Management
Financial liabilities, at fair value	1,120,901	342,156
Level 2 | Loans and financing and derivative financial liabilities
Financial risk Management
Financial liabilities, at fair value	429,268	846,187
Level 2 | Loans and financing
Financial risk Management
Financial liabilities, at fair value	414,231	808,729
Level 2 | Derivative financial instruments
Financial risk Management
Financial liabilities, at fair value	15,037	37,458
Fair value
Financial risk Management
Financial assets, at fair value	1,237,361	1,055,814
Fair value | Level 1
Financial risk Management
Financial assets, at fair value	1,153,205	981,540
Fair value | Level 2
Financial risk Management
Financial assets, at fair value	84,156	74,274
Fair value | Level 3
Financial risk Management
Financial assets, at fair value	0
Financial liabilities, at fair value	0
Cash and cash equivalents | Fair value
Financial risk Management
Financial assets, at fair value	1,019,037	915,576
Cash and cash equivalents | Fair value | Level 1
Financial risk Management
Financial assets, at fair value	1,019,037	915,576
Financial investments | Fair value
Financial risk Management
Financial assets, at fair value	206,547	119,498
Financial investments | Fair value | Level 1
Financial risk Management
Financial assets, at fair value	134,168	65,964
Financial investments | Fair value | Level 2
Financial risk Management
Financial assets, at fair value	72,379	53,534
Derivative financial instruments | Fair value
Financial risk Management
Financial assets, at fair value	11,777	20,740
Derivative financial instruments | Fair value | Level 2
Financial risk Management
Financial assets, at fair value	$ 11,777	$ 20,740

XML

Financial risk management - Derivative financial instruments and underlying hedged items (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2017 USD ($) item	Dec. 31, 2016 USD ($) item	Dec. 31, 2015 USD ($)
Financial risk Management
Derivative financial assets (liabilities)	$ (3,260)	$ (16,718)	$ 10,105
Current assets	7,483	20,740
Non-current assets	4,294
Current liabilities	(12,588)	(37,458)
Non-current liabilities	(2,449)
Operational hedges
Financial risk Management
Derivative financial assets (liabilities)	(2,859)	(486)
Realized gain (loss) on derivative instruments	(2,119)
Operational hedges | 2018
Financial risk Management
Derivative financial assets (liabilities)	(4,705)
Operational hedges | 2019
Financial risk Management
Derivative financial assets (liabilities)	(1,529)
Operational hedges | 2020
Financial risk Management
Derivative financial assets (liabilities)	3,375
Cash flow and fair value hedges
Financial risk Management
Derivative financial assets (liabilities)	(401)	(16,232)
Realized gain (loss) on derivative instruments	(36,889)
Cash flow and fair value hedges | 2018
Financial risk Management
Derivative financial assets (liabilities)	(401)
Hedging programs for sales of zinc at fixed price | Operational hedges
Financial risk Management
Derivative financial assets (liabilities)	603	369
Realized gain (loss) on derivative instruments	1,288
Hedging programs for sales of zinc at fixed price | Operational hedges | 2018
Financial risk Management
Derivative financial assets (liabilities)	589
Hedging programs for sales of zinc at fixed price | Operational hedges | 2019
Financial risk Management
Derivative financial assets (liabilities)	14
Hedging programs for operating margin of metals | Operational hedges
Financial risk Management
Derivative financial assets (liabilities)		(5,326)
Hedging programs for mismatches of quotation periods | Operational hedges
Financial risk Management
Derivative financial assets (liabilities)	(4,108)	4,471
Realized gain (loss) on derivative instruments	(2,207)
Hedging programs for mismatches of quotation periods | Operational hedges | 2018
Financial risk Management
Derivative financial assets (liabilities)	(4,108)
Hedging programs for mismatches of quotation periods | Cash flow hedges
Financial risk Management
Derivative financial assets (liabilities)	2,918	(1,728)
Realized gain (loss) on derivative instruments	4,356
Hedging programs for mismatches of quotation periods | Cash flow hedges | 2018
Financial risk Management
Derivative financial assets (liabilities)	2,918
Hedging programs for mismatches of quotation periods | Fair value hedge
Financial risk Management
Derivative financial assets (liabilities)	(3,319)	32
Realized gain (loss) on derivative instruments	(12,310)
Hedging programs for mismatches of quotation periods | Fair value hedge | 2018
Financial risk Management
Derivative financial assets (liabilities)	(3,319)
Hedging of changes in interest rates in US dollar | Operational hedges
Financial risk Management
Derivative financial assets (liabilities)	646
Realized gain (loss) on derivative instruments	(1,200)
Hedging of changes in interest rates in US dollar | Operational hedges | 2018
Financial risk Management
Derivative financial assets (liabilities)	(1,186)
Hedging of changes in interest rates in US dollar | Operational hedges | 2019
Financial risk Management
Derivative financial assets (liabilities)	(1,543)
Hedging of changes in interest rates in US dollar | Operational hedges | 2020
Financial risk Management
Derivative financial assets (liabilities)	3,375
Hedge accounting | Cash flow hedges
Financial risk Management
Derivative financial assets (liabilities)		$ (14,536)
Realized gain (loss) on derivative instruments	$ (28,935)
Zinc forward | Hedging programs for sales of zinc at fixed price | Operational hedges
Financial risk Management
Principal (ton for zinc and copper, k oz for silver, USD for dollar) | item	2,230	615
Average term (days)	127 days
Derivative financial assets (liabilities)	$ 603	$ 369
Realized gain (loss) on derivative instruments	1,288
Zinc forward | Hedging programs for sales of zinc at fixed price | Operational hedges | 2018
Financial risk Management
Derivative financial assets (liabilities)	589
Zinc forward | Hedging programs for sales of zinc at fixed price | Operational hedges | 2019
Financial risk Management
Derivative financial assets (liabilities)	$ 14
Zinc forward | Hedging programs for operating margin of metals | Operational hedges
Financial risk Management
Principal (ton for zinc and copper, k oz for silver, USD for dollar) | item		10,790
Derivative financial assets (liabilities)		$ (7,110)
Zinc forward | Hedging programs for mismatches of quotation periods | Operational hedges
Financial risk Management
Principal (ton for zinc and copper, k oz for silver, USD for dollar) | item	240,747	146,515
Average term (days)	23 days
Derivative financial assets (liabilities)	$ (4,304)	$ 4,471
Realized gain (loss) on derivative instruments	(2,183)
Zinc forward | Hedging programs for mismatches of quotation periods | Operational hedges | 2018
Financial risk Management
Derivative financial assets (liabilities)	$ (4,304)
Zinc forward | Hedging programs for mismatches of quotation periods | Cash flow hedges
Financial risk Management
Principal (ton for zinc and copper, k oz for silver, USD for dollar) | item	58,800	43,294
Average term (days)	47 days
Derivative financial assets (liabilities)	$ 2,986	$ (1,728)
Realized gain (loss) on derivative instruments	4,450
Zinc forward | Hedging programs for mismatches of quotation periods | Cash flow hedges | 2018
Financial risk Management
Derivative financial assets (liabilities)	$ 2,986
Zinc forward | Hedging programs for mismatches of quotation periods | Fair value hedge
Financial risk Management
Principal (ton for zinc and copper, k oz for silver, USD for dollar) | item	87,693	22,390
Average term (days)	43 days
Derivative financial assets (liabilities)	$ (3,319)	$ 32
Realized gain (loss) on derivative instruments	(12,310)
Zinc forward | Hedging programs for mismatches of quotation periods | Fair value hedge | 2018
Financial risk Management
Derivative financial assets (liabilities)	(3,319)
Zinc forward | Hedge accounting | Cash flow hedges
Financial risk Management
Principal (ton for zinc and copper, k oz for silver, USD for dollar) | item		94,559
Derivative financial assets (liabilities)		$ (22,967)
Realized gain (loss) on derivative instruments	$ (43,898)
Silver forward | Hedging programs for mismatches of quotation periods | Operational hedges
Financial risk Management
Principal (ton for zinc and copper, k oz for silver, USD for dollar) | item	238
Average term (days)	17 days
Derivative financial assets (liabilities)	$ 196
Realized gain (loss) on derivative instruments	(24)
Silver forward | Hedging programs for mismatches of quotation periods | Operational hedges | 2018
Financial risk Management
Derivative financial assets (liabilities)	$ 196
Silver forward | Hedging programs for mismatches of quotation periods | Cash flow hedges
Financial risk Management
Principal (ton for zinc and copper, k oz for silver, USD for dollar) | item	265
Average term (days)	58 days
Derivative financial assets (liabilities)	$ (68)
Realized gain (loss) on derivative instruments	(94)
Silver forward | Hedging programs for mismatches of quotation periods | Cash flow hedges | 2018
Financial risk Management
Derivative financial assets (liabilities)	(68)
US Dollar forward | Hedging programs for operating margin of metals | Operational hedges
Financial risk Management
Principal (ton for zinc and copper, k oz for silver, USD for dollar) | item		8,039,000
Derivative financial assets (liabilities)		$ 1,784
US Dollar forward | Hedge accounting | Cash flow hedges
Financial risk Management
Principal (ton for zinc and copper, k oz for silver, USD for dollar) | item		93,467,000
Derivative financial assets (liabilities)		$ 8,221
Realized gain (loss) on derivative instruments	$ 15,134
LIBOR floating rate vs. US Dollar fixed rate swaps | Hedging of changes in interest rates in US dollar | Operational hedges
Financial risk Management
Principal (ton for zinc and copper, k oz for silver, USD for dollar) | item	31,393,000
Average term (days)	849 days
Derivative financial assets (liabilities)	$ 646
Realized gain (loss) on derivative instruments	(1,200)
LIBOR floating rate vs. US Dollar fixed rate swaps | Hedging of changes in interest rates in US dollar | Operational hedges | 2018
Financial risk Management
Derivative financial assets (liabilities)	(1,186)
LIBOR floating rate vs. US Dollar fixed rate swaps | Hedging of changes in interest rates in US dollar | Operational hedges | 2019
Financial risk Management
Derivative financial assets (liabilities)	(1,543)
LIBOR floating rate vs. US Dollar fixed rate swaps | Hedging of changes in interest rates in US dollar | Operational hedges | 2020
Financial risk Management
Derivative financial assets (liabilities)	3,375
Copper forward | Hedge accounting | Cash flow hedges
Financial risk Management
Principal (ton for zinc and copper, k oz for silver, USD for dollar) | item		540
Derivative financial assets (liabilities)		$ 210
Realized gain (loss) on derivative instruments	$ (171)

XML

Financial risk management - Sensitivity analysis (Details) - 12 months ended Dec. 31, 2017 € in Thousands, oz in Thousands, S/ in Thousands, R$ in Thousands, $ in Thousands	USD ($)	PEN (S/) T oz	EUR (€) T oz	BRL (R$) T oz	USD ($) T oz
Scenario II
Financial risk Management
Decrease in risk assumption		(25.00%)	(25.00%)	(25.00%)	(25.00%)
Increase in risk assumption		25.00%	25.00%	25.00%	25.00%
Scenario III
Financial risk Management
Decrease in risk assumption		(50.00%)	(50.00%)	(50.00%)	(50.00%)
Increase in risk assumption		50.00%	50.00%	50.00%	50.00%
Foreign exchange risk | US Dollar | Scenario I
Financial risk Management
Decrease in risk assumption		(3.81%)	(3.81%)	(3.81%)	(3.81%)
Impacts on profit (loss)	$ (153)
Foreign exchange risk | US Dollar | Scenario II
Financial risk Management
Impacts on profit (loss)	(3,328)
Impacts on profit (loss)	(897)
Foreign exchange risk | US Dollar | Scenario III
Financial risk Management
Impacts on profit (loss)	(17,218)
Impacts on profit (loss)	(3,906)
Foreign exchange risk | BRL | Scenario I
Financial risk Management
Increase in risk assumption		3.97%	3.97%	3.97%	3.97%
Impacts on comprehensive income	6,127
Foreign exchange risk | BRL | Scenario II
Financial risk Management
Impacts on comprehensive income	53,441
Impacts on comprehensive income	(28,963)
Foreign exchange risk | BRL | Scenario III
Financial risk Management
Impacts on comprehensive income	156,447
Impacts on comprehensive income	(49,564)
Foreign exchange risk | EUR | Scenario I
Financial risk Management
Decrease in risk assumption		(1.66%)	(1.66%)	(1.66%)	(1.66%)
Impacts on profit (loss)	(28)
Foreign exchange risk | EUR | Scenario II
Financial risk Management
Impacts on profit (loss)	(423)
Impacts on profit (loss)	423
Foreign exchange risk | EUR | Scenario III
Financial risk Management
Impacts on profit (loss)	(846)
Impacts on profit (loss)	846
Foreign exchange risk | PEN | Scenario I
Financial risk Management
Increase in risk assumption		0.68%	0.68%	0.68%	0.68%
Impacts on profit (loss)	155
Foreign exchange risk | PEN | Scenario II
Financial risk Management
Impacts on profit (loss)	(5,707)
Impacts on profit (loss)	5,707
Foreign exchange risk | PEN | Scenario III
Financial risk Management
Impacts on profit (loss)	(11,415)
Impacts on profit (loss)	11,415
Foreign exchange risk | Cash, cash equivalents and financial investments | US Dollar
Financial risk Management
Net exposure					$ 11,339
Foreign exchange risk | Cash, cash equivalents and financial investments | BRL
Financial risk Management
Net exposure | R$				R$ 203,392
Foreign exchange risk | Cash, cash equivalents and financial investments | EUR
Financial risk Management
Net exposure | €			€ 1,692
Foreign exchange risk | Cash, cash equivalents and financial investments | PEN
Financial risk Management
Net exposure | S/		S/ 22,830
Foreign exchange risk | Loans and financing | US Dollar
Financial risk Management
Net exposure					40,274
Foreign exchange risk | Loans and financing | BRL
Financial risk Management
Net exposure | R$				R$ 161,706
Foreign exchange risk | Derivative financial instruments | US Dollar
Financial risk Management
Net exposure					$ 31,393
BRL - CDI interest rate risk | Scenario I
Financial risk Management
Increase in risk assumption		0.00%	0.00%	0.00%	0.00%
BRL - CDI interest rate risk | Scenario II
Financial risk Management
Impacts on profit (loss)	(2,029)
Impacts on profit (loss)	2,043
BRL - CDI interest rate risk | Scenario III
Financial risk Management
Impacts on profit (loss)	(4,044)
Impacts on profit (loss)	4,098
BRL - CDI interest rate risk | Cash, cash equivalents and financial investments
Financial risk Management
Net exposure | R$				R$ 202,311
BRL - CDI interest rate risk | Loans and financing
Financial risk Management
Net exposure | R$				70,720
BRL - CDI interest rate risk | Derivative financial instruments
Financial risk Management
Net exposure | R$				R$ 103,849
USD - LIBOR interest rate risk | Scenario I
Financial risk Management
Decrease in risk assumption		(0.02%)	(0.02%)	(0.02%)	(0.02%)
Impacts on profit (loss)	14
Impacts on comprehensive income	0
USD - LIBOR interest rate risk | Scenario II
Financial risk Management
Impacts on profit (loss)	217
Impacts on comprehensive income	(6)
Impacts on profit (loss)	(217)
Impacts on comprehensive income	6
USD - LIBOR interest rate risk | Scenario III
Financial risk Management
Impacts on profit (loss)	435
Impacts on comprehensive income	(12)
Impacts on profit (loss)	(435)
Impacts on comprehensive income	12
USD - LIBOR interest rate risk | Loans and financing
Financial risk Management
Net exposure					$ 130,610
USD - LIBOR interest rate risk | Derivative financial instruments
Financial risk Management
Net exposure					$ 1,282,900
US Dollar coupon interest rate risk | Scenario I
Financial risk Management
Increase in risk assumption		0.03%	0.03%	0.03%	0.03%
Impacts on profit (loss)	(21)
US Dollar coupon interest rate risk | Scenario II
Financial risk Management
Impacts on profit (loss)	515
Impacts on profit (loss)	(499)
US Dollar coupon interest rate risk | Scenario III
Financial risk Management
Impacts on profit (loss)	1,047
Impacts on profit (loss)	(981)
US Dollar coupon interest rate risk | Derivative financial instruments
Financial risk Management
Net exposure					$ 31,393
Zinc price risk | Scenario I
Financial risk Management
Decrease in risk assumption		(2.90%)	(2.90%)	(2.90%)	(2.90%)
Impacts on profit (loss)	13,073
Impacts on comprehensive income	(580)
Zinc price risk | Scenario II
Financial risk Management
Impacts on profit (loss)	51,744
Impacts on comprehensive income	(2,297)
Impacts on profit (loss)	(51,744)
Impacts on comprehensive income	2,297
Zinc price risk | Scenario III
Financial risk Management
Impacts on profit (loss)	103,488
Impacts on comprehensive income	(4,594)
Impacts on profit (loss)	(103,488)
Impacts on comprehensive income	4,594
Zinc price risk | Derivative financial instruments
Financial risk Management
Net exposure | T		389,470	389,470	389,470	389,470
Silver price risk | Scenario I
Financial risk Management
Increase in risk assumption		5.20%	5.20%	5.20%	5.20%
Impacts on profit (loss)	(9)
Impacts on comprehensive income	(36)
Silver price risk | Scenario II
Financial risk Management
Impacts on profit (loss)	281
Impacts on comprehensive income	1,124
Impacts on profit (loss)	(281)
Impacts on comprehensive income	(1,124)
Silver price risk | Scenario III
Financial risk Management
Impacts on profit (loss)	562
Impacts on comprehensive income	2,248
Impacts on profit (loss)	(562)
Impacts on comprehensive income	$ (2,248)
Silver price risk | Derivative financial instruments
Financial risk Management
Net exposure | oz		503	503	503	503

XML

Financial instruments by category - Analysis (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Financial instruments by category
Financial assets	$ 1,420,812	$ 1,576,674
Financial liabilities	2,017,407	1,822,804
Loans and financing
Financial instruments by category
Financial liabilities	1,447,299	1,144,385
Derivative financial instruments
Financial instruments by category
Financial liabilities	15,037	37,458
Trade payables
Financial instruments by category
Financial liabilities	329,814	282,241
Confirming payable
Financial instruments by category
Financial liabilities	111,024	102,287
Use of public asset
Financial instruments by category
Financial liabilities	24,309	25,920
Related parties
Financial instruments by category
Financial liabilities	89,924	230,513
Cash and cash equivalents
Financial instruments by category
Financial assets	1,019,037	915,576
Financial investments
Financial instruments by category
Financial assets	206,547	119,498
Derivative financial instruments
Financial instruments by category
Financial assets	11,777	20,740
Trade accounts receivable
Financial instruments by category
Financial assets	182,713	120,062
Related parties
Financial instruments by category
Financial assets	738	400,798
Loans and receivables
Financial instruments by category
Financial assets	1,202,488	1,436,436
Loans and receivables | Cash and cash equivalents
Financial instruments by category
Financial assets	1,019,037	915,576
Loans and receivables | Trade accounts receivable
Financial instruments by category
Financial assets	182,713	120,062
Loans and receivables | Related parties
Financial instruments by category
Financial assets	738	400,798
Assets held for trading
Financial instruments by category
Financial assets	215,358	126,147
Assets held for trading | Financial investments
Financial instruments by category
Financial assets	206,547	119,498
Assets held for trading | Derivative financial instruments
Financial instruments by category
Financial assets	8,811	6,649
Derivatives used for hedging
Financial instruments by category
Financial assets	2,966	14,091
Derivatives used for hedging | Derivative financial instruments
Financial instruments by category
Financial assets	2,966	14,091
Liabilities at fair value through profit or loss
Financial instruments by category
Financial liabilities	12,842	2,564
Liabilities at fair value through profit or loss | Derivative financial instruments
Financial instruments by category
Financial liabilities	12,842	2,564
Derivatives used for hedging
Financial instruments by category
Financial liabilities	2,195	34,894
Derivatives used for hedging | Derivative financial instruments
Financial instruments by category
Financial liabilities	2,195	34,894
Other financial liabilities
Financial instruments by category
Financial liabilities	2,002,370	1,785,346
Other financial liabilities | Loans and financing
Financial instruments by category
Financial liabilities	1,447,299	1,144,385
Other financial liabilities | Trade payables
Financial instruments by category
Financial liabilities	329,814	282,241
Other financial liabilities | Confirming payable
Financial instruments by category
Financial liabilities	111,024	102,287
Other financial liabilities | Use of public asset
Financial instruments by category
Financial liabilities	24,309	25,920
Other financial liabilities | Related parties
Financial instruments by category
Financial liabilities	$ 89,924	$ 230,513

XML

Credit quality of financial assets (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Credit quality of financial assets
Financial assets	$ 1,420,812	$ 1,576,674
Cash and cash equivalents, financial investments and derivative financial instruments
Credit quality of financial assets
Financial assets	1,237,361	1,055,814
Cash and cash equivalents, financial investments and derivative financial instruments | Local
Credit quality of financial assets
Financial assets	208,152	440,547
Cash and cash equivalents, financial investments and derivative financial instruments | Global
Credit quality of financial assets
Financial assets	1,029,209	615,267
Cash and cash equivalents
Credit quality of financial assets
Financial assets	1,019,037	915,576
Cash and cash equivalents | AA+
Credit quality of financial assets
Financial assets	1,089	5,917
Cash and cash equivalents | AA-
Credit quality of financial assets
Financial assets	115,269	263,737
Cash and cash equivalents | A+
Credit quality of financial assets
Financial assets	172,052	114,463
Cash and cash equivalents | A
Credit quality of financial assets
Financial assets	235,445	65,398
Cash and cash equivalents | A-
Credit quality of financial assets
Financial assets	86,192	109,969
Cash and cash equivalents | BBB+
Credit quality of financial assets
Financial assets	96,436	75,972
Cash and cash equivalents | BBB
Credit quality of financial assets
Financial assets	110,733	121,320
Cash and cash equivalents | BB
Credit quality of financial assets
Financial assets		2,239
Cash and cash equivalents | No rating
Credit quality of financial assets
Financial assets	201,821	156,561
Cash and cash equivalents | Local
Credit quality of financial assets
Financial assets	1,092	319,717
Cash and cash equivalents | Local | AA+
Credit quality of financial assets
Financial assets	1,089	5,917
Cash and cash equivalents | Local | AA-
Credit quality of financial assets
Financial assets		13,699
Cash and cash equivalents | Local | A+
Credit quality of financial assets
Financial assets		4,919
Cash and cash equivalents | Local | A-
Credit quality of financial assets
Financial assets	3	15,515
Cash and cash equivalents | Local | BBB+
Credit quality of financial assets
Financial assets		75,952
Cash and cash equivalents | Local | BBB
Credit quality of financial assets
Financial assets		121,111
Cash and cash equivalents | Local | BB
Credit quality of financial assets
Financial assets		2,239
Cash and cash equivalents | Local | No rating
Credit quality of financial assets
Financial assets		80,365
Cash and cash equivalents | Global
Credit quality of financial assets
Financial assets	1,017,945	595,859
Cash and cash equivalents | Global | AA-
Credit quality of financial assets
Financial assets	115,269	250,038
Cash and cash equivalents | Global | A+
Credit quality of financial assets
Financial assets	172,052	109,544
Cash and cash equivalents | Global | A
Credit quality of financial assets
Financial assets	235,445	65,398
Cash and cash equivalents | Global | A-
Credit quality of financial assets
Financial assets	86,189	94,454
Cash and cash equivalents | Global | BBB+
Credit quality of financial assets
Financial assets	96,436	20
Cash and cash equivalents | Global | BBB
Credit quality of financial assets
Financial assets	110,733	209
Cash and cash equivalents | Global | No rating
Credit quality of financial assets
Financial assets	201,821	76,196
Financial investments
Credit quality of financial assets
Financial assets	206,547	119,498
Financial investments | AA+
Credit quality of financial assets
Financial assets	17,111
Financial investments | AA-
Credit quality of financial assets
Financial assets	184,365	113,732
Financial investments | A-
Credit quality of financial assets
Financial assets	5,053	3,225
Financial investments | No rating
Credit quality of financial assets
Financial assets	18	2,541
Financial investments | Local
Credit quality of financial assets
Financial assets	202,291	113,732
Financial investments | Local | AA+
Credit quality of financial assets
Financial assets	17,111
Financial investments | Local | AA-
Credit quality of financial assets
Financial assets	180,127	113,732
Financial investments | Local | A-
Credit quality of financial assets
Financial assets	5,053
Financial investments | Global
Credit quality of financial assets
Financial assets	4,256	5,766
Financial investments | Global | AA-
Credit quality of financial assets
Financial assets	4,238
Financial investments | Global | A-
Credit quality of financial assets
Financial assets		3,225
Financial investments | Global | No rating
Credit quality of financial assets
Financial assets	18	2,541
Derivative financial instruments
Credit quality of financial assets
Financial assets	11,777	20,740
Derivative financial instruments | AA-
Credit quality of financial assets
Financial assets	8,403	5,511
Derivative financial instruments | A+
Credit quality of financial assets
Financial assets	3,141	1,667
Derivative financial instruments | A
Credit quality of financial assets
Financial assets	233	4,826
Derivative financial instruments | A-
Credit quality of financial assets
Financial assets		8,736
Derivative financial instruments | Local
Credit quality of financial assets
Financial assets	4,769	7,098
Derivative financial instruments | Local | AA-
Credit quality of financial assets
Financial assets	4,769	5,511
Derivative financial instruments | Local | A+
Credit quality of financial assets
Financial assets		1,587
Derivative financial instruments | Global
Credit quality of financial assets
Financial assets	7,008	13,642
Derivative financial instruments | Global | AA-
Credit quality of financial assets
Financial assets	3,634
Derivative financial instruments | Global | A+
Credit quality of financial assets
Financial assets	3,141	80
Derivative financial instruments | Global | A
Credit quality of financial assets
Financial assets	$ 233	4,826
Derivative financial instruments | Global | A-
Credit quality of financial assets
Financial assets		$ 8,736

XML

Cash and cash equivalents (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Cash and cash equivalents
Cash and banks	$ 319,920	$ 338,054
Term deposits	699,117	577,522
Total cash and cash equivalents	$ 1,019,037	$ 915,576	$ 621,415	$ 750,679

XML

Financial investments (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Financial investments
Financial investments	$ 206,547	$ 119,498	$ 57,856
Nexa's stake in investment fund	11.00%	8.00%
Assets held for trading
Financial investments
Financial investments	$ 206,547	$ 119,498
Assets held for trading | Investment fund quotas
Financial investments
Financial investments	138,945	95,504
Assets held for trading | Repurchase agreements - Public securities
Financial investments
Financial investments	131,999	60,803
Assets held for trading | Repurchase agreements
Financial investments
Financial investments	5,900	20,797
Assets held for trading | Bank Deposit Certificate
Financial investments
Financial investments		13,009
Assets held for trading | Financial Treasury Bills
Financial investments
Financial investments	1,046	891
Assets held for trading | Credit Right Investment Funds
Financial investments
Financial investments		4
Assets held for trading | Bank Deposit Certificate
Financial investments
Financial investments	42,067	15,042
Assets held for trading | Repurchase agreements
Financial investments
Financial investments	18,289
Assets held for trading | Credit Rights Investment Funds
Financial investments
Financial investments	5,053	4,682
Assets held for trading | Financial Treasury Bills
Financial investments
Financial investments	1,123	$ 4,270
Assets held for trading | Other
Financial investments
Financial investments	$ 1,070

XML

Trade accounts receivable - Composition (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Disclosure of composition of trade accounts receivable
Number of days for recognition of provision for uncollectible trade receivables	120 days
Related parties	$ 3,775	$ 6,389
Total trade accounts receivable	182,713	120,062
Cost/gross carrying amount
Disclosure of composition of trade accounts receivable
Trade receivables	181,084	115,291
Related parties	3,775	6,389
Total trade accounts receivable	184,859	121,680
Provision for inventory/trade receivables
Disclosure of composition of trade accounts receivable
Total trade accounts receivable	$ (2,146)	$ (1,618)

XML

Trade accounts receivable - Provision for uncollectible receivables (Details) - Trade accounts receivable - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Disclosure of changes in provision for uncollectible trade receivables
Balance at the beginning of the year	$ (1,618)	$ (2,047)
Reversals (additions), net	(521)	653
Exchange variation losses	(7)	(224)
Balance at the end of the year	$ (2,146)	$ (1,618)

XML

Trade accounts receivable - Analysis by currency (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Disclosure of analysis of trade accounts receivable by currency
Trade accounts receivable	$ 182,713	$ 120,062
BRL
Disclosure of analysis of trade accounts receivable by currency
Trade accounts receivable	66,486	44,924
US Dollar
Disclosure of analysis of trade accounts receivable by currency
Trade accounts receivable	115,879	74,868
Other
Disclosure of analysis of trade accounts receivable by currency
Trade accounts receivable	$ 348	$ 270

XML

Trade accounts receivable - Aging (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Disclosure of aging of trade accounts receivable
Trade accounts receivable	$ 182,713	$ 120,062
Cost/gross carrying amount
Disclosure of aging of trade accounts receivable
Trade accounts receivable	184,859	121,680
Cost/gross carrying amount | To fall due
Disclosure of aging of trade accounts receivable
Trade accounts receivable	163,196	113,155
Cost/gross carrying amount | Up to 3 months
Disclosure of aging of trade accounts receivable
Trade accounts receivable	19,775	6,054
Cost/gross carrying amount | From 3 to 6 months
Disclosure of aging of trade accounts receivable
Trade accounts receivable	914	1,169
Cost/gross carrying amount | Over 6 months
Disclosure of aging of trade accounts receivable
Trade accounts receivable	974	1,302
Provision for inventory/trade receivables
Disclosure of aging of trade accounts receivable
Trade accounts receivable	$ (2,146)	$ (1,618)

XML

Inventory - Composition (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Inventory
Total	$ 324,878	$ 291,768
Provision for inventory/trade receivables
Inventory
Total	(20,736)	(38,384)	$ (36,985)
Cost/gross carrying amount
Inventory
Finished products	106,026	121,969
Semi-finished products	85,458	65,054
Raw materials	30,128	17,511
Auxiliary materials and consumables	81,261	104,972
Imports in transit	41,878	20,631
Other	$ 863	$ 15

XML

Inventory - Provision (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Changes in the provision for obsolete and slow-moving inventory
Beginning balance	$ 291,768
Ending balance	324,878	$ 291,768
Provision for inventory/trade receivables
Changes in the provision for obsolete and slow-moving inventory
Beginning balance	(38,384)	(36,985)
Reversals (additions), net	17,435	3,090
Exchange variation gains (losses)	213	(4,489)
Ending balance	(20,736)	(38,384)
Provision for inventory/trade receivables | Finished products
Changes in the provision for obsolete and slow-moving inventory
Beginning balance	(768)
Reversals (additions), net	727
Exchange variation gains (losses)	1
Ending balance	(40)	(768)
Provision for inventory/trade receivables | Semi-finished products
Changes in the provision for obsolete and slow-moving inventory
Beginning balance	(10,167)
Reversals (additions), net	(2)
Exchange variation gains (losses)	150
Ending balance	(10,019)	(10,167)
Provision for inventory/trade receivables | Raw materials
Changes in the provision for obsolete and slow-moving inventory
Beginning balance	(153)
Reversals (additions), net	(63)
Exchange variation gains (losses)	2
Ending balance	(214)	(153)
Provision for inventory/trade receivables | Auxiliary materials and consumables
Changes in the provision for obsolete and slow-moving inventory
Beginning balance	(27,296)
Reversals (additions), net	16,773
Exchange variation gains (losses)	60
Ending balance	$ (10,463)	$ (27,296)

XML

Taxes recoverable (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Taxes Recoverable.
Value-added Tax on Sales and Services	$ 50,616	$ 64,428
Corporate taxes on Net Income	25,165	34,130
Social Contribution on Revenue	18,824	16,831
Social Integration Program	4,302	3,959
Other	13,737	10,384
Total	112,644	129,732
Taxes recoverable
Current	80,134	102,996
Non-current	$ 32,510	$ 26,736

XML

Related parties - Transactions (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Related parties
Trade accounts receivable	$ 3,775	$ 6,389
Trade accounts receivable, current	3,775	6,389
Non-current assets	738	400,798
Trade payables	7,043	10,025
Trade payables, current	7,043	10,025
Dividends payable	4,138	7,185
Dividends payable, current	4,138	7,185
Current liabilities	87,686	222,917
Non-current liabilities	2,238	7,596
Current and non-current liabilities	89,924	230,513
Votorantim S.A.
Related parties
Trade accounts receivable	8	75
Non-current assets	3	3
Trade payables	336	257
Current and non-current liabilities	87,686	52,873
Additional liability derived from energy assets	24,928	52,873
Accrual for right to retain energy assets	62,733
Companhia Brasileira de Aluminio
Related parties
Trade accounts receivable	1,843	3,847
Non-current assets		399,725
Trade payables	5,246	9,064
Dividends payable		2,423
Current and non-current liabilities	13	5,614
Votorantim Cimentos S.A.
Related parties
Trade accounts receivable	1,696	1,891
Non-current assets	735	750
Trade payables	47	24
Other related parties
Related parties
Trade accounts receivable	228	576
Non-current assets		320
Trade payables	1,414	680
Dividends payable	655
Current and non-current liabilities	2,225	1,956
Non-controlling interests
Related parties
Dividends payable	$ 3,483	4,762
Current and non-current liabilities		$ 170,070

XML

Related parties - Sales, Purchases and Financial results (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Related parties
Sales	$ 2,263	$ 2,971	$ 13,797
Purchases	57,443	46,313	42,915
Financial results	1,012	7,165	5,702
Companhia Brasileira de Aluminio
Related parties
Sales	2,125	70	23
Purchases	42,434	31,162	3,924
Financial results	1,012	3,582
Votoratim Metais S.A.
Related parties
Purchases		51	29
Financial results		3,583	5,702
Votener Votorantim Comercializadora de Energia Ltda.
Related parties
Sales			12,436
Purchases	13,510	13,400	28,869
Votorantim Cimentos S.A.
Related parties
Sales	138	45	73
Purchases	365	273	338
Other related parties
Related parties
Sales		2,856	1,265
Purchases	$ 1,134	$ 1,427	$ 9,755

XML

Related parties (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Related parties.
Short-term benefits to managers	$ 6,668	$ 7,310	$ 4,945
Other long-term benefits to key management	1,162	1,686	836
Total key management compensation	$ 7,830	$ 8,996	$ 5,781

XML

Property, plant and equipment (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Reconciliation of changes in property plant and equipment
Balance at the beginning of the year	$ 1,978,462	$ 1,883,354
Acquisitions	196,717	180,856
Disposals, property, plant and equipment	(10,982)	(13,339)
Depreciation, property, plant and equipment	(195,437)	(200,043)
Reversal of provision for asset impairment		979
Exchange variation losses	(18,958)	130,093
Transfers	2,671
Cash flow/cost review and restatement of interest rates	43,789	(3,186)
Transfers of assets held for sale	252	(252)
Balance at the end of the year	1,996,514	1,978,462
Impairment during the period	0
Cost/gross carrying amount
Reconciliation of changes in property plant and equipment
Balance at the beginning of the year	4,130,590	3,662,146
Balance at the end of the year	4,170,586	4,130,590
Accumulated depreciation/amortization
Reconciliation of changes in property plant and equipment
Balance at the beginning of the year	(2,152,128)	(1,778,792)
Balance at the end of the year	(2,174,072)	(2,152,128)
Land and improvements
Reconciliation of changes in property plant and equipment
Balance at the beginning of the year	23,779	20,572
Acquisitions	46
Disposals, property, plant and equipment	(930)	(46)
Depreciation, property, plant and equipment	(22)	(20)
Exchange variation losses	(231)	2,274
Transfers	1,573	999
Balance at the end of the year	24,215	23,779
Land and improvements | Cost/gross carrying amount
Reconciliation of changes in property plant and equipment
Balance at the beginning of the year	24,036	20,657
Balance at the end of the year	24,490	24,036
Land and improvements | Accumulated depreciation/amortization
Reconciliation of changes in property plant and equipment
Balance at the beginning of the year	(257)	(85)
Balance at the end of the year	(275)	(257)
Dam and buildings
Reconciliation of changes in property plant and equipment
Balance at the beginning of the year	544,870	483,967
Acquisitions	100
Disposals, property, plant and equipment	(92)	(593)
Depreciation, property, plant and equipment	(34,175)	(31,145)
Exchange variation losses	(4,309)	38,640
Transfers	71,152	54,001
Balance at the end of the year	$ 577,546	$ 544,870
Average annual depreciation rates - %	4.00%	4.00%
Dam and buildings | Cost/gross carrying amount
Reconciliation of changes in property plant and equipment
Balance at the beginning of the year	$ 980,242	$ 816,001
Balance at the end of the year	1,030,686	980,242
Dam and buildings | Accumulated depreciation/amortization
Reconciliation of changes in property plant and equipment
Balance at the beginning of the year	(435,372)	(332,034)
Balance at the end of the year	(453,140)	(435,372)
Machinery, equipment and facilities
Reconciliation of changes in property plant and equipment
Balance at the beginning of the year	980,326	963,753
Acquisitions	5,761	489
Disposals, property, plant and equipment	(2,915)	(1,525)
Depreciation, property, plant and equipment	(142,519)	(145,450)
Exchange variation losses	(6,381)	64,510
Transfers	83,297	98,801
Transfers of assets held for sale	252	(252)
Balance at the end of the year	$ 917,821	$ 980,326
Average annual depreciation rates - %	7.00%	7.00%
Machinery, equipment and facilities | Cost/gross carrying amount
Reconciliation of changes in property plant and equipment
Balance at the beginning of the year	$ 2,466,265	$ 2,223,583
Balance at the end of the year	2,422,254	2,466,265
Machinery, equipment and facilities | Accumulated depreciation/amortization
Reconciliation of changes in property plant and equipment
Balance at the beginning of the year	(1,485,939)	(1,259,830)
Balance at the end of the year	(1,504,433)	(1,485,939)
Vehicles
Reconciliation of changes in property plant and equipment
Balance at the beginning of the year	1,823	2,485
Acquisitions	272
Disposals, property, plant and equipment		(95)
Depreciation, property, plant and equipment	(1,174)	(1,487)
Exchange variation losses	(101)	259
Transfers	2,236	661
Balance at the end of the year	$ 3,056	$ 1,823
Average annual depreciation rates - %	24.00%	21.00%
Vehicles | Cost/gross carrying amount
Reconciliation of changes in property plant and equipment
Balance at the beginning of the year	$ 22,263	$ 20,551
Balance at the end of the year	21,135	22,263
Vehicles | Accumulated depreciation/amortization
Reconciliation of changes in property plant and equipment
Balance at the beginning of the year	(20,440)	(18,066)
Balance at the end of the year	(18,079)	(20,440)
Furniture and fixtures
Reconciliation of changes in property plant and equipment
Balance at the beginning of the year	2,452	2,837
Acquisitions	307	2
Disposals, property, plant and equipment	(121)	(37)
Depreciation, property, plant and equipment	(509)	(477)
Exchange variation losses	(9)	43
Transfers	131	84
Balance at the end of the year	$ 2,251	$ 2,452
Average annual depreciation rates - %	10.00%	11.00%
Furniture and fixtures | Cost/gross carrying amount
Reconciliation of changes in property plant and equipment
Balance at the beginning of the year	$ 6,895	$ 6,278
Balance at the end of the year	6,743	6,895
Furniture and fixtures | Accumulated depreciation/amortization
Reconciliation of changes in property plant and equipment
Balance at the beginning of the year	(4,443)	(3,441)
Balance at the end of the year	(4,492)	(4,443)
Assets and projects under construction, PPE
Reconciliation of changes in property plant and equipment
Balance at the beginning of the year	219,254	206,094
Acquisitions	185,688	151,302
Disposals, property, plant and equipment	(6,917)	(42)
Reversal of provision for asset impairment		979
Exchange variation losses	(3,965)	16,987
Transfers	(158,559)	(156,066)
Balance at the end of the year	235,501	219,254
Assets and projects under construction, PPE | Cost/gross carrying amount
Reconciliation of changes in property plant and equipment
Balance at the beginning of the year	219,254	206,094
Balance at the end of the year	235,501	219,254
Asset retirement obligation (ARO)
Reconciliation of changes in property plant and equipment
Balance at the beginning of the year	36,716	42,466
Acquisitions	4,303	148
Depreciation, property, plant and equipment	(5,834)	(7,301)
Exchange variation losses	(1,839)	4,589
Cash flow/cost review and restatement of interest rates	43,789	(3,186)
Balance at the end of the year	$ 77,135	$ 36,716
Average annual depreciation rates - %	5.00%	7.00%
Asset retirement obligation (ARO) | Cost/gross carrying amount
Reconciliation of changes in property plant and equipment
Balance at the beginning of the year	$ 132,824	$ 116,695
Balance at the end of the year	178,662	132,824
Asset retirement obligation (ARO) | Accumulated depreciation/amortization
Reconciliation of changes in property plant and equipment
Balance at the beginning of the year	(96,108)	(74,229)
Balance at the end of the year	(101,527)	(96,108)
Mining projects
Reconciliation of changes in property plant and equipment
Balance at the beginning of the year	168,638	160,664
Acquisitions	240	28,915
Disposals, property, plant and equipment		(11,000)
Depreciation, property, plant and equipment	(11,121)	(14,096)
Exchange variation losses	(2,115)	2,652
Transfers	2,841	1,503
Balance at the end of the year	$ 158,483	$ 168,638
Average annual depreciation rates - %	8.00%	8.00%
Mining projects | Cost/gross carrying amount
Reconciliation of changes in property plant and equipment
Balance at the beginning of the year	$ 271,466	$ 246,208
Balance at the end of the year	243,938	271,466
Mining projects | Accumulated depreciation/amortization
Reconciliation of changes in property plant and equipment
Balance at the beginning of the year	(102,828)	(85,544)
Balance at the end of the year	(85,455)	(102,828)
Other PPE
Reconciliation of changes in property plant and equipment
Balance at the beginning of the year	604	516
Disposals, property, plant and equipment	(7)	(1)
Depreciation, property, plant and equipment	(83)	(67)
Exchange variation losses	(8)	139
Transfers		17
Balance at the end of the year	506	604
Other PPE | Cost/gross carrying amount
Reconciliation of changes in property plant and equipment
Balance at the beginning of the year	7,345	6,079
Balance at the end of the year	7,177	7,345
Other PPE | Accumulated depreciation/amortization
Reconciliation of changes in property plant and equipment
Balance at the beginning of the year	(6,741)	(5,563)
Balance at the end of the year	$ (6,671)	$ (6,741)

XML

Property, plant and equipment - Leases (Details) - Land and equipment - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Carrying amount of land and equipment acquired through finance leases
Property, plant and equipment under finance lease	$ 8,833	$ 4,137
Cost/gross carrying amount
Carrying amount of land and equipment acquired through finance leases
Property, plant and equipment under finance lease	19,763	13,794
Accumulated depreciation/amortization
Carrying amount of land and equipment acquired through finance leases
Property, plant and equipment under finance lease	$ (10,930)	$ (9,657)

XML

Property, plant and equipment - Assets and projects under constructions (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Assets and projects under constructions
Property, plant and equipment	$ 1,996,514	$ 1,978,462	$ 1,883,354
Assets and projects under construction, PPE
Assets and projects under constructions
Property, plant and equipment	235,501	219,254	$ 206,094
Borrowing charges capitalized	$ 10,630	$ 6,493
Average capitalization rate (per month)	0.68%	0.69%
Mining projects under construction
Assets and projects under constructions
Property, plant and equipment	$ 101,922	$ 91,174
Acquisition and renovation of equipment
Assets and projects under constructions
Property, plant and equipment	42,239	52,284
Security, health and environment projects
Assets and projects under constructions
Property, plant and equipment	35,858	44,674
New production line construction
Assets and projects under constructions
Property, plant and equipment	25,477	5,472
Information technology
Assets and projects under constructions
Property, plant and equipment	3,084	151
Modernization and increased production projects
Assets and projects under constructions
Property, plant and equipment	10,563	10,004
Other projects under construction
Assets and projects under constructions
Property, plant and equipment	$ 16,358	$ 15,495

XML

Intangible assets - Accounting policy (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Disclosure of detailed information about intangible assets
Amortisation, intangible assets other than goodwill	$ 75,017	$ 74,991
Rights to use natural resources
Disclosure of detailed information about intangible assets
Amortisation, intangible assets other than goodwill	$ 74,024	$ 74,013
Rights to use natural resources | Peru
Disclosure of detailed information about intangible assets
Percentage of company's right to use natural resources	98.00%
Conversion rate from inferred mineral resources into measured and indicated mineral resources	100.00%	100.00%	97.00%
Percentage of inferred resources included when calculating expected life of mine	70.00%
Amortisation calculated using only proven and probable reserves and measured and indicated resources, intangible assets other than goodwill	$ 82,270	$ 82,594
Additional amortisation calculated using only proven and probable reserves and measured and indicated resources, intangible assets other than goodwill	9,392	9,716
Amortisation, intangible assets other than goodwill	72,878	72,878
Software
Disclosure of detailed information about intangible assets
Amortisation, intangible assets other than goodwill	$ 576	$ 73
Software | Minimum
Disclosure of detailed information about intangible assets
Useful lives, intangible assets other than goodwill	3 years
Software | Maximum
Disclosure of detailed information about intangible assets
Useful lives, intangible assets other than goodwill	5 years

XML

Intangible assets - Analysis (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Disclosure of reconciliation of changes in intangible assets and goodwill
Balance at the beginning of the year	$ 1,903,152	$ 1,968,879
Acquisitions	921	2,133
Disposals	(36)
Amortization	(75,017)	(74,991)
Exchange variation gains (losses)	(3,630)	7,131
Transfers	(2,671)
Balance at the end of the year	1,822,719	1,903,152
Impairment loss recognised in profit or loss, intangible assets and goodwill	0
Goodwill
Disclosure of reconciliation of changes in intangible assets and goodwill
Balance at the beginning of the year	675,561	674,769
Exchange variation gains (losses)	(2,274)	792
Balance at the end of the year	673,287	675,561
Rights to use natural resources
Disclosure of reconciliation of changes in intangible assets and goodwill
Balance at the beginning of the year	1,203,710	1,274,236
Amortization	(74,024)	(74,013)
Exchange variation gains (losses)	(682)	3,487
Balance at the end of the year	$ 1,129,004	$ 1,203,710
Average annual amortization rates %	5.00%	5.00%
Software
Disclosure of reconciliation of changes in intangible assets and goodwill
Balance at the beginning of the year	$ 401	$ 129
Acquisitions	921
Disposals	(36)
Amortization	(576)	(73)
Exchange variation gains (losses)	(21)	(41)
Transfers	4,768	386
Balance at the end of the year	$ 5,457	$ 401
Average annual amortization rates %	20.00%	20.00%
Use of public assets
Disclosure of reconciliation of changes in intangible assets and goodwill
Balance at the beginning of the year	$ 7,422	$ 6,518
Amortization	(394)	(363)
Exchange variation gains (losses)	(96)	1,267
Balance at the end of the year	$ 6,932	$ 7,422
Average annual amortization rates %	3.00%	3.00%
Assets and projects under construction
Disclosure of reconciliation of changes in intangible assets and goodwill
Balance at the beginning of the year	$ 6,974	$ 5,238
Acquisitions		2,133
Exchange variation gains (losses)	(424)
Transfers	(6,546)	(397)
Balance at the end of the year	4	6,974
Other
Disclosure of reconciliation of changes in intangible assets and goodwill
Balance at the beginning of the year	9,084	7,989
Amortization	(23)	(542)
Exchange variation gains (losses)	(133)	1,626
Transfers	(893)	11
Balance at the end of the year	8,035	9,084
Cost/gross carrying amount
Disclosure of reconciliation of changes in intangible assets and goodwill
Balance at the beginning of the year	2,403,767	2,390,061
Balance at the end of the year	2,408,302	2,403,767
Cost/gross carrying amount | Goodwill
Disclosure of reconciliation of changes in intangible assets and goodwill
Balance at the beginning of the year	675,561	674,769
Balance at the end of the year	673,287	675,561
Cost/gross carrying amount | Rights to use natural resources
Disclosure of reconciliation of changes in intangible assets and goodwill
Balance at the beginning of the year	1,673,091	1,669,901
Balance at the end of the year	1,672,931	1,673,091
Cost/gross carrying amount | Software
Disclosure of reconciliation of changes in intangible assets and goodwill
Balance at the beginning of the year	1,507	469
Balance at the end of the year	21,823	1,507
Cost/gross carrying amount | Use of public assets
Disclosure of reconciliation of changes in intangible assets and goodwill
Balance at the beginning of the year	11,581	9,666
Balance at the end of the year	11,410	11,581
Cost/gross carrying amount | Assets and projects under construction
Disclosure of reconciliation of changes in intangible assets and goodwill
Balance at the beginning of the year	6,974	5,238
Balance at the end of the year	4	6,974
Cost/gross carrying amount | Other
Disclosure of reconciliation of changes in intangible assets and goodwill
Balance at the beginning of the year	35,053	30,018
Balance at the end of the year	28,847	35,053
Accumulated depreciation/amortization
Disclosure of reconciliation of changes in intangible assets and goodwill
Balance at the beginning of the year	(500,615)	(421,182)
Balance at the end of the year	(585,583)	(500,615)
Accumulated depreciation/amortization | Rights to use natural resources
Disclosure of reconciliation of changes in intangible assets and goodwill
Balance at the beginning of the year	(469,381)	(395,665)
Balance at the end of the year	(543,927)	(469,381)
Accumulated depreciation/amortization | Software
Disclosure of reconciliation of changes in intangible assets and goodwill
Balance at the beginning of the year	(1,106)	(340)
Balance at the end of the year	(16,366)	(1,106)
Accumulated depreciation/amortization | Use of public assets
Disclosure of reconciliation of changes in intangible assets and goodwill
Balance at the beginning of the year	(4,159)	(3,148)
Balance at the end of the year	(4,478)	(4,159)
Accumulated depreciation/amortization | Other
Disclosure of reconciliation of changes in intangible assets and goodwill
Balance at the beginning of the year	(25,969)	(22,029)
Balance at the end of the year	$ (20,812)	$ (25,969)

XML

Intangible assets - Impairment testing of goodwill (Details) $ in Thousands		12 Months Ended
	Sep. 30, 2017 USD ($) $ / T	Dec. 31, 2017 USD ($)
Disclosure of impairment testing of goodwill
Zinc (US$ per ton) | $ / T	2,509
Copper (US$ per ton) | $ / T	6,362
Impairment loss recognised in profit or loss, intangible assets and goodwill		$ 0
Zinc price after reasonably possible decrease in long-term metal price | $ / T	2,383
Goodwill
Disclosure of impairment testing of goodwill
Length of period for financial budgets used for cash flow projections		5 years
Discount Rate	10.60%
Goodwill and net identifiable assets acquired in business combination	$ 1,868,238
NEXA PERU
Disclosure of impairment testing of goodwill
Percentage of reasonably possible decrease in long-term metal price	5.00%
Increase (decrease) in profit due to reasonably possible decrease in long-term metal price		$ (95,238)
Percentage of reasonably possible increase in discount rate	2.00%
Increase (decrease) in profit due to reasonably possible increase in discount rate		$ (102,238)
Minimum
Disclosure of impairment testing of goodwill
Mines	7 years
Greenfield	13 years
Maximum
Disclosure of impairment testing of goodwill
Mines	12 years
Greenfield	27 years

XML

Loans and Financings - Analysis (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Loans and Financings
Current	$ 40,841	$ 62,601
Non-current	1,406,458	1,081,784
Total borrowings	1,447,299	1,144,385	$ 1,056,210
Current portion of long term loans and financing (principal)	28,019	57,137
Interest on loans and financing	12,822	5,464
Total current borrowings and current portion of non-current borrowings	40,841	62,601
Fair value disclosed
Loans and Financings
Total borrowings	1,535,132	1,150,885
Eurobonds - USD
Loans and Financings
Current	8,778	4,054
Non-current	1,032,664	343,000
Total borrowings	1,041,442	347,054
Total current borrowings and current portion of non-current borrowings	8,778	4,054
Eurobonds - USD | Fair value disclosed
Loans and Financings
Total borrowings	1,120,901	342,156
Debt with banks
Loans and Financings
Current	435	24,038
Non-current	199,179	662,743
Total borrowings	199,614	686,781
Total current borrowings and current portion of non-current borrowings	435	24,038
Debt with banks | Fair value disclosed
Loans and Financings
Total borrowings	214,293	712,371
Debt with BNDES
Loans and Financings
Current	19,795	32,619
Non-current	73,653	67,672
Total borrowings	93,448	100,291
Total current borrowings and current portion of non-current borrowings	19,795	32,619
Debt with BNDES | Fair value disclosed
Loans and Financings
Total borrowings	85,969	86,908
Debentures
Loans and Financings
Current	8,885	504
Non-current	32,403	3,822
Total borrowings	41,288	4,326
Total current borrowings and current portion of non-current borrowings	8,885	504
Debentures | Fair value disclosed
Loans and Financings
Total borrowings	41,405	4,235
Export credit note
Loans and Financings
Current	1,102
Non-current	61,622
Total borrowings	62,724
Total current borrowings and current portion of non-current borrowings	1,102
Export credit note | Fair value disclosed
Loans and Financings
Total borrowings	64,058
Debt with FINEP
Loans and Financings
Current	677	682
Non-current	2,062	2,743
Total borrowings	2,739	3,425
Total current borrowings and current portion of non-current borrowings	677	682
Debt with FINEP | Fair value disclosed
Loans and Financings
Total borrowings	2,640	3,038
Debt with FINAME
Loans and Financings
Current	398	407
Non-current	1,383	1,804
Total borrowings	1,781	2,211
Total current borrowings and current portion of non-current borrowings	398	407
Debt with FINAME | Fair value disclosed
Loans and Financings
Total borrowings	1,604	1,828
Other
Loans and Financings
Current	771	297
Non-current	3,492
Total borrowings	4,263	297
Total current borrowings and current portion of non-current borrowings	771	297
Other | Fair value disclosed
Loans and Financings
Total borrowings	$ 4,262	349
Fixed interest rate, USD | Eurobonds - USD
Loans and Financings
Interest rate (as a percent)	5.19%
Fixed interest rate, USD | Other
Loans and Financings
Interest rate (as a percent)	5.93%
Fixed interest rate, BRL | Debt with BNDES
Loans and Financings
Interest rate (as a percent)	4.74%
Fixed interest rate, BRL | Debt with FINAME
Loans and Financings
Interest rate (as a percent)	4.59%
LIBOR 3M | Debt with banks
Loans and Financings
Borrowings, adjustment to interest rate basis	2.57%
LIBOR 3M | Export credit note
Loans and Financings
Borrowings, adjustment to interest rate basis	1.85%
LIBOR 6M | Debt with banks
Loans and Financings
Borrowings, adjustment to interest rate basis	2.51%
TJLP
Loans and Financings
Current	$ 12,509	23,078
Non-current	35,341	41,632
Total borrowings	47,850	64,710
Total current borrowings and current portion of non-current borrowings	$ 12,509	23,078
TJLP | Debt with BNDES
Loans and Financings
Borrowings, adjustment to interest rate basis	2.68%
TJLP | Debt with FINEP
Loans and Financings
Borrowings, adjustment to interest rate basis	0.68%
SELIC | Debt with BNDES
Loans and Financings
Borrowings, adjustment to interest rate basis	2.78%
UMBNDES
Loans and Financings
Current	$ 3,211	6,042
Non-current	5,496	9,087
Total borrowings	8,707	15,129
Total current borrowings and current portion of non-current borrowings	$ 3,211	6,042
UMBNDES | Debt with BNDES
Loans and Financings
Borrowings, adjustment to interest rate basis	2.44%
CDI
Loans and Financings
Current	$ 9,811	504
Non-current	62,632	3,822
Total borrowings	72,443	4,326
Total current borrowings and current portion of non-current borrowings	$ 9,811	$ 504
CDI | Debentures
Loans and Financings
Borrowings, percentage of reference rate	107.77%
CDI | Export credit note
Loans and Financings
Borrowings, percentage of reference rate	118.00%

XML

Loans and Financings - Maturity Profile (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Loans and Financings
Borrowings, principal amount	$ 1,448,194
Borrowings, interest accrual and costs	(895)
Total borrowings	$ 1,447,299	$ 1,144,385	$ 1,056,210
Borrowings, percentage of total	100.00%
Eurobonds - USD
Loans and Financings
Borrowings, principal amount	$ 1,043,000
Borrowings, interest accrual and costs	(1,558)
Total borrowings	1,041,442	347,054
Debt with banks
Loans and Financings
Borrowings, principal amount	199,999
Borrowings, interest accrual and costs	(385)
Total borrowings	199,614	686,781
Debt with BNDES
Loans and Financings
Borrowings, principal amount	94,204
Borrowings, interest accrual and costs	(756)
Total borrowings	93,448	100,291
Debentures
Loans and Financings
Borrowings, principal amount	40,595
Borrowings, interest accrual and costs	693
Total borrowings	41,288	4,326
Export credit note
Loans and Financings
Borrowings, principal amount	61,623
Borrowings, interest accrual and costs	1,101
Total borrowings	62,724
Debt with FINEP
Loans and Financings
Borrowings, principal amount	2,732
Borrowings, interest accrual and costs	7
Total borrowings	2,739	3,425
Debt with FINAME
Loans and Financings
Borrowings, principal amount	1,778
Borrowings, interest accrual and costs	3
Total borrowings	1,781	2,211
Other
Loans and Financings
Borrowings, principal amount	4,263
Total borrowings	4,263	$ 297
2018
Loans and Financings
Borrowings, principal amount	29,687
Borrowings, interest accrual and costs	11,154
Total borrowings	$ 40,841
Borrowings, percentage of total	4.00%
2018 | Eurobonds - USD
Loans and Financings
Borrowings, interest accrual and costs	$ 8,778
Total borrowings	8,778
2018 | Debt with banks
Loans and Financings
Borrowings, interest accrual and costs	435
Total borrowings	435
2018 | Debt with BNDES
Loans and Financings
Borrowings, principal amount	19,732
Borrowings, interest accrual and costs	63
Total borrowings	19,795
2018 | Debentures
Loans and Financings
Borrowings, principal amount	8,119
Borrowings, interest accrual and costs	767
Total borrowings	8,886
2018 | Export credit note
Loans and Financings
Borrowings, interest accrual and costs	1,101
Total borrowings	1,101
2018 | Debt with FINEP
Loans and Financings
Borrowings, principal amount	669
Borrowings, interest accrual and costs	7
Total borrowings	676
2018 | Debt with FINAME
Loans and Financings
Borrowings, principal amount	395
Borrowings, interest accrual and costs	3
Total borrowings	398
2018 | Other
Loans and Financings
Borrowings, principal amount	772
Total borrowings	772
2019
Loans and Financings
Borrowings, principal amount	64,488
Borrowings, interest accrual and costs	(1,714)
Total borrowings	$ 62,774
Borrowings, percentage of total	4.00%
2019 | Eurobonds - USD
Loans and Financings
Borrowings, interest accrual and costs	$ (1,177)
Total borrowings	(1,177)
2019 | Debt with banks
Loans and Financings
Borrowings, principal amount	31,111
Borrowings, interest accrual and costs	(281)
Total borrowings	30,830
2019 | Debt with BNDES
Loans and Financings
Borrowings, principal amount	23,379
Borrowings, interest accrual and costs	(225)
Total borrowings	23,154
2019 | Debentures
Loans and Financings
Borrowings, principal amount	8,119
Borrowings, interest accrual and costs	(31)
Total borrowings	8,088
2019 | Debt with FINEP
Loans and Financings
Borrowings, principal amount	669
Total borrowings	669
2019 | Debt with FINAME
Loans and Financings
Borrowings, principal amount	392
Total borrowings	392
2019 | Other
Loans and Financings
Borrowings, principal amount	818
Total borrowings	818
2020
Loans and Financings
Borrowings, principal amount	172,383
Borrowings, interest accrual and costs	(1,712)
Total borrowings	$ 170,671
Borrowings, percentage of total	12.00%
2020 | Eurobonds - USD
Loans and Financings
Borrowings, interest accrual and costs	$ (1,227)
Total borrowings	(1,227)
2020 | Debt with banks
Loans and Financings
Borrowings, principal amount	84,444
Borrowings, interest accrual and costs	(281)
Total borrowings	84,163
2020 | Debt with BNDES
Loans and Financings
Borrowings, principal amount	16,288
Borrowings, interest accrual and costs	(179)
Total borrowings	16,109
2020 | Debentures
Loans and Financings
Borrowings, principal amount	8,119
Borrowings, interest accrual and costs	(25)
Total borrowings	8,094
2020 | Export credit note
Loans and Financings
Borrowings, principal amount	61,623
Total borrowings	61,623
2020 | Debt with FINEP
Loans and Financings
Borrowings, principal amount	669
Total borrowings	669
2020 | Debt with FINAME
Loans and Financings
Borrowings, principal amount	374
Total borrowings	374
2020 | Other
Loans and Financings
Borrowings, principal amount	866
Total borrowings	866
2021
Loans and Financings
Borrowings, principal amount	107,168
Borrowings, interest accrual and costs	(1,712)
Total borrowings	$ 105,456
Borrowings, percentage of total	7.00%
2021 | Eurobonds - USD
Loans and Financings
Borrowings, interest accrual and costs	$ (1,280)
Total borrowings	(1,280)
2021 | Debt with banks
Loans and Financings
Borrowings, principal amount	84,444
Borrowings, interest accrual and costs	(258)
Total borrowings	84,186
2021 | Debt with BNDES
Loans and Financings
Borrowings, principal amount	12,703
Borrowings, interest accrual and costs	(165)
Total borrowings	12,538
2021 | Debentures
Loans and Financings
Borrowings, principal amount	8,119
Borrowings, interest accrual and costs	(9)
Total borrowings	8,110
2021 | Debt with FINEP
Loans and Financings
Borrowings, principal amount	669
Total borrowings	669
2021 | Debt with FINAME
Loans and Financings
Borrowings, principal amount	315
Total borrowings	315
2021 | Other
Loans and Financings
Borrowings, principal amount	918
Total borrowings	918
2022
Loans and Financings
Borrowings, principal amount	18,795
Borrowings, interest accrual and costs	(1,455)
Total borrowings	$ 17,340
Borrowings, percentage of total	1.00%
2022 | Eurobonds - USD
Loans and Financings
Borrowings, interest accrual and costs	$ (1,337)
Total borrowings	(1,337)
2022 | Debt with BNDES
Loans and Financings
Borrowings, principal amount	9,500
Borrowings, interest accrual and costs	(109)
Total borrowings	9,391
2022 | Debentures
Loans and Financings
Borrowings, principal amount	8,119
Borrowings, interest accrual and costs	(9)
Total borrowings	8,110
2022 | Debt with FINEP
Loans and Financings
Borrowings, principal amount	56
Total borrowings	56
2022 | Debt with FINAME
Loans and Financings
Borrowings, principal amount	231
Total borrowings	231
2022 | Other
Loans and Financings
Borrowings, principal amount	889
Total borrowings	889
2023
Loans and Financings
Borrowings, principal amount	348,354
Borrowings, interest accrual and costs	(1,232)
Total borrowings	$ 347,122
Borrowings, percentage of total	24.00%
2023 | Eurobonds - USD
Loans and Financings
Borrowings, principal amount	$ 343,000
Borrowings, interest accrual and costs	(1,172)
Total borrowings	341,828
2023 | Debt with BNDES
Loans and Financings
Borrowings, principal amount	5,284
Borrowings, interest accrual and costs	(60)
Total borrowings	5,224
2023 | Debt with FINAME
Loans and Financings
Borrowings, principal amount	70
Total borrowings	70
2024
Loans and Financings
Borrowings, principal amount	3,068
Borrowings, interest accrual and costs	(1,194)
Total borrowings	$ 1,874
Borrowings, percentage of total	0.00%
2024 | Eurobonds - USD
Loans and Financings
Borrowings, interest accrual and costs	$ (1,160)
Total borrowings	(1,160)
2024 | Debt with BNDES
Loans and Financings
Borrowings, principal amount	3,067
Borrowings, interest accrual and costs	(34)
Total borrowings	3,033
2024 | Debt with FINAME
Loans and Financings
Borrowings, principal amount	1
Total borrowings	1
As from 2025
Loans and Financings
Borrowings, principal amount	704,251
Borrowings, interest accrual and costs	(3,030)
Total borrowings	$ 701,221
Borrowings, percentage of total	48.00%
As from 2025 | Eurobonds - USD
Loans and Financings
Borrowings, principal amount	$ 700,000
Borrowings, interest accrual and costs	(2,983)
Total borrowings	697,017
As from 2025 | Debt with BNDES
Loans and Financings
Borrowings, principal amount	4,251
Borrowings, interest accrual and costs	(47)
Total borrowings	$ 4,204

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Loans and Financings - Changes (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Changes in Loans and Financings
Balance at the beginning of the year	$ 1,144,385	$ 1,056,210
Payments	(537,254)	(483,100)
New Loans and Financing	837,819	550,966
Exchange variation	(2,873)	17,834
Interest accrual	69,481	38,511
Interest paid	(57,038)	(35,689)
Addition of borrowing fees, net of amortization	(7,221)	(347)
Balance at the end of the year	$ 1,447,299	$ 1,144,385

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Loans and Financings - Analysis by currency (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Loans and Financings
Current	$ 40,841	$ 62,601
Non-current	1,406,458	1,081,784
Total	1,447,299	1,144,385	$ 1,056,210
US Dollar
Loans and Financings
Current	13,260	31,496
Non-current	1,272,223	1,013,988
Total	1,285,483	1,045,484
BRL
Loans and Financings
Current	27,471	28,170
Non-current	134,235	66,954
Total	161,706	95,124
Currency basket
Loans and Financings
Current	110	2,935
Non-current		842
Total	$ 110	$ 3,777

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Loans and Financings - Analysis by index (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Loans and Financings
Current	$ 40,841	$ 62,601
Non-current	1,406,458	1,081,784
Total	1,447,299	1,144,385	$ 1,056,210
Fixed rate
Loans and Financings
Current	11,192	6,466
Non-current	1,038,459	346,997
Total	1,049,651	353,463
LIBOR
Loans and Financings
Current	610	24,037
Non-current	230,573	662,743
Total	231,183	686,780
TJLP
Loans and Financings
Current	12,509	23,078
Non-current	35,341	41,632
Total	47,850	64,710
UMBNDES
Loans and Financings
Current	3,211	6,042
Non-current	5,496	9,087
Total	8,707	15,129
CDI
Loans and Financings
Current	9,811	504
Non-current	62,632	3,822
Total	72,443	4,326
BNDES Selic
Loans and Financings
Current	3,508	2,474
Non-current	33,957	17,503
Total	$ 37,465	$ 19,977

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Loans and Financings - Guarantees, Covenants, Subsidiary bonds and Revolving Credit Facility (Details) - USD ($) $ in Thousands	May 04, 2017	Mar. 28, 2013	Dec. 31, 2017	Dec. 31, 2016	Jun. 30, 2015
Loans and Financings
Borrowings guaranteed by sureties			$ 1,063,784	$ 780,579
Borrowings guaranteed by fiduciary liens			$ 1,781	$ 2,211
Guarantee percentage			130.00%
Maximum borrowing capacity on revolving credit facility					$ 225,000
Ten-year bond
Loans and Financings
Principal amount	$ 700,000
Term of the bond	10 years
Interest rate (as a percent)	5.375%
NEXA PERU | Subsidiary bonds
Loans and Financings
Principal amount		$ 350,000
Term of the bond		10 years
NEXA PERU | Fixed rate | Subsidiary bonds
Loans and Financings
Interest rate (as a percent)		4.625%

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Confirming payables (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Confirming payables
Suppliers payment term (in days)	90 days
Extended supplier payment terms (in days)	180 days
Confirming payable	$ 111,024	$ 102,287

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Salaries and payroll charges (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Salaries and payroll charges
Direct remuneration and social charges	$ 21,357	$ 18,655
Provision for profit sharing and other payable	58,441	51,367
Salaries and payroll charges	$ 79,798	$ 70,022

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Taxes payable (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Taxes payable
Corporate taxes on income	$ 24,108	$ 18,145
Special mining lien and special mining tax	8,731	664
Withholding taxes	3,737	3,494
Value-added tax on sales and services	366	6,393
Social contribution on revenue	185	182
Social integration program	39	39
Other	3,943	931
Taxes payable	$ 41,109	$ 29,848

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Current and deferred taxes on income - Reconciliation of taxes on income expenses (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Reconciliation of taxes on income expenses
Profit before taxation			$ 271,459	$ 208,892	$ (178,257)
Standard rate			27.08%	29.22%	29.22%
Taxes on income at standard rates			$ (73,511)	$ (61,038)	$ 52,087
Tax effect from share in results of investees			16	(46)	(75)
Difference in tax rate for subsidiaries outside Luxembourg			(19,912)	(11,425)	4,138
Re-measurement of deferred tax - change in Peru tax rate				(41,588)
Taxes on dividend received from foreign subsidiary			(8,299)
Taxes of prior years			(5,381)	1,127
Difference arising on carrying non-current assets using a different base			12,144	2,458	(18,310)
Other permanent (additions) exclusions, net			(11,251)	12,129	939
Taxes on income on the income statement			(106,194)	(98,383)	38,779
Current			(125,691)	(75,282)	(62,758)
Deferred			$ 19,497	$ (23,101)	$ 101,537
Scenario, Forecast [Member]
Reconciliation of taxes on income expenses
Standard rate		26.01%
Peru
Reconciliation of taxes on income expenses
Standard rate			29.50%	28.00%	28.00%	30.00%
Expected Applicable Tax Rate			27.00%
Peru | Scenario, Forecast [Member]
Reconciliation of taxes on income expenses
Expected Applicable Tax Rate	26.00%	27.00%

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Current and deferred taxes on income - Analysis of deferred tax balances (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Analysis of deferred tax balances
Net deferred tax assets related to the same legal entity	$ 224,513	$ 221,304
Net deferred tax liabilities related to the same legal entity	(324,931)	(328,608)
Total	(100,418)	(107,304)	$ (119,351)
Tax credits on non-operating losses
Analysis of deferred tax balances
Tax credits	104,100	102,555
Exchange variation losses
Analysis of deferred tax balances
Tax credits	79,430	84,536
Environmental obligation
Analysis of deferred tax balances
Tax credits	28,504	27,206
Asset retirement obligation
Analysis of deferred tax balances
Tax credits	23,990	22,085
Tax, civil and labor provisions
Analysis of deferred tax balances
Tax credits	15,666	16,904
Other provisions
Analysis of deferred tax balances
Tax credits	12,481	13,792
Provision for profit sharing
Analysis of deferred tax balances
Tax credits	6,521	6,322
Provision for inventory losses
Analysis of deferred tax balances
Tax credits	4,395	5,202
Use of public asset
Analysis of deferred tax balances
Tax credits	4,093	4,305
Provision for impairment of trade receivables
Analysis of deferred tax balances
Tax credits	1,110	743
Adjustment to present value
Analysis of deferred tax balances
Tax debits on temporary differences	(1,253)	(1,269)
Capitalized interest
Analysis of deferred tax balances
Tax debits on temporary differences	(10,624)	(7,184)
Accelerated depreciation and adjustment of useful lives
Analysis of deferred tax balances
Tax debits on temporary differences	(28,371)	(20,748)
Depreciation and amortization of fair value adjustment to PP&E and intangible assets
Analysis of deferred tax balances
Tax debits on temporary differences	(344,531)	(363,604)
Other differences
Analysis of deferred tax balances
Tax credits	5,028	1,863
Tax debits on temporary differences	(957)	$ (12)
Unutilised tax losses resulting from its holding activities in Luxembourg
Analysis of deferred tax balances
Tax credits	$ 0

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Current and deferred taxes on income - Effects of deferred tax and taxes on profit or loss for the year and other comprehensive income (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Effects of deferred tax and taxes on profit or loss for the year and other comprehensive income
Balance at beginning of year	$ (107,304)	$ (119,351)
Effect on income for the period	19,497	(23,101)	$ 101,537
Effect on comprehensive income	(4,119)	8,825
Exchange variation	(8,492)	26,323
Balance at end of year	$ (100,418)	$ (107,304)	$ (119,351)

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Current and deferred taxes on income - Tax effects relating to components of other comprehensive income (loss) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Tax effects relating to components of other comprehensive income (loss)
Operating cash flow hedge accounting, Before tax	$ 16,675	$ (25,081)
Operating cash flow hedge accounting, (Charge) credit	(4,119)	8,825
Operating cash flow hedge accounting, After tax	$ 12,556	$ (16,256)	$ 5,832

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Provisions (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Provisions reconciliation
Balance at the beginning of the year	$ 296,879	$ 197,359
Present value adjustment	4,654	2,617
Additions	47,816	104,749
Reversals	(42,019)	(11,794)
Judicial deposits, net of write-off	3,275	(6,530)
Write-off	(18,666)	(7,678)
Interest and indexation	8,822	4,926
Exchange variation	(2,367)	16,416
Companies excluded from the consolidation	(1,022)
Cost and interest revision	43,789	(3,186)
Balance at the end of the year	341,161	296,879
Current	14,641
Non-current	326,520	296,879
Asset retirement obligation
Provisions reconciliation
Balance at the beginning of the year	159,117
Present value adjustment	846
Additions	4,303
Write-off	(5,068)
Exchange variation	(2,520)
Companies excluded from the consolidation	(1,022)
Cost and interest revision	43,789
Balance at the end of the year	199,445	$ 159,117
Non-current	$ 199,445
Increase in interest rate (as a percent)	1.00%
Change in liability due to increase in interest rate	$ (8,131)
Decrease in interest rate (as a percent)	1.00%
Change in liability due to decrease in interest rate	$ 9,525
Asset retirement obligation | Brazil
Provisions reconciliation
Cost and interest revision	43,789
Provision related to cost revision	38,541
Provision related to interest revision	$ 5,248
Interest rate (as a percent)	7.83%	8.47%
Change in liability due to increase in interest rate	$ (7,996)
Change in liability due to decrease in interest rate	8,961
Asset retirement obligation | Ambrosia
Provisions reconciliation
Additions	4,227
Asset retirement obligation | Peru
Provisions reconciliation
Change in liability due to increase in interest rate	(1,235)
Change in liability due to decrease in interest rate	$ 564
Asset retirement obligation | Peru | Minimum
Provisions reconciliation
Interest rate (as a percent)	1.47%	0.50%
Asset retirement obligation | Peru | Maximum
Provisions reconciliation
Interest rate (as a percent)	2.45%	2.45%
Environmental obligation
Provisions reconciliation
Balance at the beginning of the year	$ 80,016
Present value adjustment	3,808
Additions	16,843
Reversals	(13,176)
Write-off	(3,847)
Exchange variation	191
Balance at the end of the year	83,835	$ 80,016
Current	14,641
Non-current	69,194
Environmental obligation | Brazil
Provisions reconciliation
Additions	16,843
Tax
Provisions reconciliation
Balance at the beginning of the year	26,299
Additions	4,503
Reversals	(14,569)
Judicial deposits, net of write-off	695
Write-off	(2,932)
Interest and indexation	4,429
Exchange variation	150
Balance at the end of the year	18,575	26,299
Non-current	18,575
Labor
Provisions reconciliation
Balance at the beginning of the year	11,773
Additions	11,765
Reversals	(10,359)
Judicial deposits, net of write-off	3,358
Write-off	(3,703)
Interest and indexation	3,818
Exchange variation	(231)
Balance at the end of the year	16,421	11,773
Non-current	16,421
Civil
Provisions reconciliation
Balance at the beginning of the year	15,415
Additions	5,832
Reversals	(63)
Judicial deposits, net of write-off	(778)
Write-off	(2,508)
Interest and indexation	341
Exchange variation	81
Balance at the end of the year	18,320	15,415
Non-current	18,320
Environmental
Provisions reconciliation
Balance at the beginning of the year	4,259
Additions	4,570
Reversals	(3,852)
Write-off	(608)
Interest and indexation	234
Exchange variation	(38)
Balance at the end of the year	4,565	$ 4,259
Non-current	$ 4,565

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Provisions - Tax, civil, labor and environmental provisions (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Provisions and the corresponding judicial deposits
Total other provisions	$ 341,161	$ 296,879	$ 197,359
Outstanding judicial deposits	10,949	14,160
Judicial provision
Provisions and the corresponding judicial deposits
Judicial deposits	(7,841)	(10,351)
Provision	65,722	68,097
Total other provisions	57,881	57,746
Outstanding judicial deposits	10,949	14,160
Tax
Provisions and the corresponding judicial deposits
Judicial deposits	(2,318)	(2,232)
Provision	20,893	28,531
Total other provisions	18,575	26,299
Outstanding judicial deposits	3,130	5,158
Labor
Provisions and the corresponding judicial deposits
Judicial deposits	(4,765)	(8,116)
Provision	21,186	19,889
Total other provisions	16,421	11,773
Outstanding judicial deposits	7,408	8,994
Civil
Provisions and the corresponding judicial deposits
Judicial deposits	(758)	(3)
Provision	19,078	15,418
Total other provisions	18,320	15,415
Outstanding judicial deposits	23	8
Environmental
Provisions and the corresponding judicial deposits
Provision	4,565	4,259
Total other provisions	4,565	$ 4,259
Outstanding judicial deposits	$ 388

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Provisions - Litigation with likelihood of loss considered possible (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Litigation with likelihood of loss considered possible
Amount under litigation considered as a possible loss	$ 330,602	$ 308,088
Tax
Litigation with likelihood of loss considered possible
Amount under litigation considered as a possible loss	125,438	94,076
Labor
Litigation with likelihood of loss considered possible
Amount under litigation considered as a possible loss	46,402	55,278
Civil
Litigation with likelihood of loss considered possible
Amount under litigation considered as a possible loss	24,911	28,185
Environmental
Litigation with likelihood of loss considered possible
Amount under litigation considered as a possible loss	$ 133,851	$ 130,549

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Provisions - Contingent liabilities - Narrative (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2017 USD ($) item	Dec. 31, 2016 USD ($)
Contingent tax liabilities with likelihood of loss considered possible
Amount under litigation considered as a possible loss	$ 330,602	$ 308,088
Tax
Contingent tax liabilities with likelihood of loss considered possible
Amount under litigation considered as a possible loss	125,438	94,076
Compensation for exploration for mineral resources | NEXA BR
Contingent tax liabilities with likelihood of loss considered possible
Amount under litigation considered as a possible loss	8,799
Disallowance of ICMS credits | NEXA BR
Contingent tax liabilities with likelihood of loss considered possible
Amount under litigation considered as a possible loss	10,273
Disallowance of PIS credits | NEXA BR
Contingent tax liabilities with likelihood of loss considered possible
Amount under litigation considered as a possible loss	8,143
Income taxes and social contribution | NEXA BR
Contingent tax liabilities with likelihood of loss considered possible
Amount under litigation considered as a possible loss	5,891
Disallowance of COFINS credits | NEXA BR
Contingent tax liabilities with likelihood of loss considered possible
Amount under litigation considered as a possible loss	5,534
Value-added Tax on Sales and Services (ICMS) on Energy | NEXA BR
Contingent tax liabilities with likelihood of loss considered possible
Amount under litigation considered as a possible loss	5,236
Value-added Tax on Sales and Services (ICMS) | NEXA BR
Contingent tax liabilities with likelihood of loss considered possible
Amount under litigation considered as a possible loss	$ 9,842
ICSM sales and services tax rate	4.00%
Civil
Contingent tax liabilities with likelihood of loss considered possible
Amount under litigation considered as a possible loss	$ 24,911	$ 28,185
Number of civil contingent liabilities | item	2
Indemnity lawsuits | NEXA BR
Contingent tax liabilities with likelihood of loss considered possible
Amount under litigation considered as a possible loss	$ 11,690
Construction of a tailings dam claim | NEXA BR
Contingent tax liabilities with likelihood of loss considered possible
Amount under litigation considered as a possible loss	$ 2,016

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Use of public Assets (Details) - USD ($) $ in Thousands			12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Use of public assets
Term of the contract for use of public assets			35 years	35 years
Intangible asset	$ 1,822,719	$ 1,903,152	$ 1,822,719	$ 1,903,152	$ 1,968,879
Liabilities	24,309	25,920	24,309	25,920
Liabilities, current	1,649	1,663	1,649	1,663
Liabilities, non-current	$ 22,660	$ 24,257	22,660	24,257
Capim Branco Energia
Use of public assets
Ownership interest (as a percent)	12.63%	12.63%
Liabilities	$ 3,085	$ 3,357	$ 3,085	$ 3,357
Picada
Use of public assets
Ownership interest (as a percent)			100.00%	100.00%
Liabilities	$ 19,535	$ 20,776	$ 19,535	$ 20,776
Campos Novos Energia S.A. - "Enercan"
Use of public assets
Ownership interest (as a percent)	20.98%	20.98%
Liabilities	$ 1,689	$ 1,787	1,689	1,787
Use of public assets
Use of public assets
Intangible asset	6,932	7,422	6,932	7,422	$ 6,518
Use of public assets | Capim Branco Energia
Use of public assets
Intangible asset	800	890	800	890
Use of public assets | Picada
Use of public assets
Intangible asset	5,502	5,856	5,502	5,856
Use of public assets | Campos Novos Energia S.A. - "Enercan"
Use of public assets
Intangible asset	$ 630	$ 676	$ 630	$ 676

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Deferred revenue (Details) $ in Thousands		12 Months Ended
	Dec. 21, 2016 USD ($)	Dec. 31, 2017 USD ($) oz	Dec. 31, 2017 USD ($)	Dec. 31, 2016 USD ($)	Dec. 20, 2016 USD ($) oz
Movement in deferred income
Balance at the beginning of the period		$ 250,000
Revenue recognition for ore delivery		(36,299)
Deferred revenue, accretion		8,184
Balance at the end of the period		221,885
Current			$ 31,296	$ 37,980
Non-current			190,589	212,020
Deferred income		$ 250,000	$ 221,885	$ 250,000
NEXA UK | Triple Flag
Deferred Revenue
Sale of silver certificates (as a percent)					65.00%
Sale of silver certificates, threshold limit | oz					19,500
Sale of silver content, once the threshold limit is reached (as a percent)					25.00%
Advance payment receivable as consideration for silver certificates					$ 250,000
Additional payment on the date of delivery (as a percent)					10.00%
Prepayments received	$ 250,000
Silver certificates delivered (in ounces) | oz		2,372,983
Revenue from sale of silver certificates		$ 36,299

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Equity - Capital and Share premium (Details) - USD ($) shares in Thousands, $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Equity.
Paid-up capital	$ 133,320	$ 1,041,416
Paid-up capital, shares	133,320	1,041,416
Share premium	$ 1,123,755	$ 339,228

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Equity - Accumulated other comprehensive income (loss) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Reconciliation of Changes in Accumulated Other Comprehensive Income
Beginning balance	$ 3,324,316	$ 3,528,475	$ 3,876,368
Currency translation of investees located abroad	(10,742)	30,373	(74,163)
Remeasurements of retirement benefits			535
Operating cash flow hedge accounting	12,556	(16,256)	5,832
Ending balance	2,908,903	3,324,316	3,528,475
Accumulated other comprehensive income
Reconciliation of Changes in Accumulated Other Comprehensive Income
Beginning balance	(163,536)	(177,653)	(109,857)
Currency translation of investees located abroad	(10,742)	30,373	(74,163)
Remeasurements of retirement benefits			535
Operating cash flow hedge accounting	12,556	(16,256)	5,832
Achievement of remeasurements with retirement benefits	(3,327)
Ending balance	(165,049)	(163,536)	(177,653)
Exchange variation on investments abroad
Reconciliation of Changes in Accumulated Other Comprehensive Income
Beginning balance	(89,087)	(119,460)	(45,297)
Currency translation of investees located abroad	(10,742)	30,373	(74,163)
Ending balance	(99,829)	(89,087)	(119,460)
Remeasurements with retirement benefits
Reconciliation of Changes in Accumulated Other Comprehensive Income
Beginning balance	3,327	3,327	2,792
Remeasurements of retirement benefits			535
Achievement of remeasurements with retirement benefits	(3,327)
Ending balance		3,327	3,327
Hedge accounting
Reconciliation of Changes in Accumulated Other Comprehensive Income
Beginning balance	(9,980)	6,276	444
Operating cash flow hedge accounting	12,556	(16,256)	5,832
Ending balance	$ 2,576	$ (9,980)	$ 6,276

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Equity - Earnings per share Basic (loss) (Details) - USD ($) $ / shares in Units, $ in Thousands	1 Months Ended				12 Months Ended
	Oct. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Apr. 30, 2016	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Basic
Shares cancelled	428,595,552	300,000,000	200,000,000	350,000,000
Profit (loss) attributable to the owners of the parent					$ 126,885	$ 93,167	$ (129,461)
Weighted average number of outstanding common shares					116,527,000	80,699,000	1,874,000
Earnings (loss) per share in US Dollars					$ 1.09	$ 1.15	$ (69.08)

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Equity - Non-controlling interests (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Disclosure of non-controlling interests
Current assets	$ 1,838,907	$ 1,592,067
Current liabilities	768,215	875,873
Non-current assets	4,122,617	4,568,486
Non-current liabilities	2,284,406	1,960,364
Accumulated NCI	422,068	476,344
Nexa Resources Cajamarquilla S.A. - "NEXA CJM" (formely Votorantim Metais Cajamarquilla S.A. - "CJM")
Disclosure of non-controlling interests
Current assets	1,105,182	1,159,112
Current liabilities	469,291	462,428
Current net assets	635,891	696,684
Non-current assets	2,852,410	3,070,147
Non-current liabilities	987,143	1,107,542
Non-current net assets	1,865,267	1,962,605
Net assets	2,501,158	2,659,289
Accumulated NCI	361,265	385,762
Pollarix S. A.
Disclosure of non-controlling interests
Current assets	6,717	26,128
Current liabilities	911	12,667
Current net assets	5,806	13,461
Non-current assets	110,246	161,595
Non-current liabilities	24,978	39,184
Non-current net assets	85,268	122,411
Net assets	91,074	135,872
Accumulated NCI	$ 60,716	$ 90,581

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Net revenue (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Net revenue
Gross revenue	$ 2,709,236	$ 2,193,867	$ 2,072,439
Taxes on sales and returns	(259,752)	(229,026)	(207,256)
Net revenue	2,449,484	1,964,841	1,865,183
Brazil
Net revenue
Net revenue	721,640	560,878	534,141
Peru
Net revenue
Net revenue	696,527	573,884	584,450
United States
Net revenue
Net revenue	158,060	156,634	99,884
Luxembourg
Net revenue
Net revenue	130,723	100,631	98,159
Switzerland
Net revenue
Net revenue	108,798	59,873	135,450
Argentina
Net revenue
Net revenue	79,463	45,050	14,904
Japan
Net revenue
Net revenue	69,565	36,005	32,994
Singapore
Net revenue
Net revenue	60,857	42,666	72,514
Colombia
Net revenue
Net revenue	47,734	39,137	42,007
Chile
Net revenue
Net revenue	38,101	67,546	52,865
Austria
Net revenue
Net revenue	37,270	22,982	18,731
Turkey
Net revenue
Net revenue	35,522	19,498	23,265
Germany
Net revenue
Net revenue	23,154	42,560	22,348
China
Net revenue
Net revenue	18,172	12,838	639
Italy
Net revenue
Net revenue	15,799	3,608	1,399
Korea
Net revenue
Net revenue	7,064	66,887	51,181
Other countries
Net revenue
Net revenue	201,035	114,164	80,252
US Dollar
Net revenue
Net revenue	1,729,234	1,414,992	1,334,878
BRL
Net revenue
Net revenue	717,032	547,537	529,218
Other
Net revenue
Net revenue	$ 3,218	$ 2,312	$ 1,087

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Expenses by nature (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Expenses by nature
Raw materials and consumables used	$ 1,120,540	$ 956,909	$ 980,533
Employee benefit expenses	278,285	233,755	202,876
Depreciation and amortization	270,454	275,034	295,258
Freight costs	75,674	68,962	73,871
Services, miscellaneous	156,491	89,426	77,772
Other expenses	17,239	32,967	23,838
Total	1,918,683	1,657,053	1,654,148
Reconciliation
Cost of products sold	1,681,202	1,439,101	1,463,290
Selling expenses	89,239	90,647	84,559
General and administrative expenses	148,242	127,305	106,299
Total	$ 1,918,683	$ 1,657,053	$ 1,654,148

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Employee benefit expenses (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2017 USD ($) employee	Dec. 31, 2016 USD ($) employee	Dec. 31, 2015 USD ($)
Employee benefit expenses
Direct remuneration	$ 146,766	$ 126,570	$ 112,072
Social charges	76,677	66,863	60,761
Benefits	54,842	40,322	30,043
Total	$ 278,285	$ 233,755	$ 202,876
Average staff headcount | employee	5,643	5,561

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Other operating expenses, net (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Other operating expenses, net
Environmental and asset retirement obligations	$ 433	$ (68,605)
Mining obligations	(11,498)	(8,967)	$ (8,953)
Project expenses	(94,280)	(48,562)	(37,623)
Net operating hedge loss	(18,785)	(33,514)	7,045
Judicial (provision) reversion	258	(15,331)
Loss on sale of property, plant and equipment and intangibles assets	(694)	(552)	(3,446)
Gain on sale of investment	4,588	408
Impairment of property, plant, equipment and intangibles		979	(8,574)
Other operating expenses, net	(9,243)	(3,675)	4,446
Total other operating expenses, net	$ (129,221)	$ (177,819)	$ (47,105)

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Net financial results (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Finance income
Gain on financial investments	$ 21,388	$ 12,032	$ 9,132
Interest on loans with related parties (Note 13)	1,012	7,165	5,702
Monetary adjustment of assets	1,881	1,507	1,147
Interest on financial assets	2,621	2,921	1,387
Other finance income	2,966	1,330	1,900
Total finance income	29,868	24,955	19,268
Finance costs
Interest on loans and financing	(56,434)	(36,059)	(33,073)
Interest on deferred revenue	(8,184)
Monetary adjustment of provisions	(9,478)	(9,595)	(5,966)
Charges on discounting of trade bills	(5,379)	(6,105)	(4,524)
Present value adjustment	(9,180)	(4,291)	(3,341)
Other finance costs	(17,514)	(14,324)	(14,721)
Total finance costs	(106,169)	(70,374)	(61,625)
Exchange and monetary variations, net	(53,880)	124,500	(299,574)
Finance results, net	$ (130,181)	$ 79,081	$ (341,931)

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Information by business segment and geographic area (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2017 USD ($) segment item	Dec. 31, 2016 USD ($)	Dec. 31, 2015 USD ($)
Information by business segment and geographic area
Number of business segments | segment	2
Revenue	$ 2,449,484	$ 1,964,841	$ 1,865,183
Cost of products sold	(1,681,202)	(1,439,101)	(1,463,290)
Gross profit	$ 768,282	525,740	401,893
Mining
Information by business segment and geographic area
Number of operating units | item	5
Revenue	$ 491,758	469,187	420,663
Smelting
Information by business segment and geographic area
Number of operating units | item	3
Revenue	$ 1,952,006	1,491,988	1,421,307
Operating segment | Mining
Information by business segment and geographic area
Revenue	1,213,221	907,425	770,704
Cost of products sold	(581,029)	(513,135)	(532,097)
Gross profit	632,192	394,290	238,607
Operating segment | Smelting
Information by business segment and geographic area
Revenue	1,952,006	1,491,988	1,421,307
Cost of products sold	(1,698,325)	(1,260,519)	(1,170,545)
Gross profit	253,681	231,469	250,762
Elimination
Information by business segment and geographic area
Revenue	(721,463)	(438,238)	(350,041)
Cost of products sold	721,463	438,238	350,041
Elimination | Mining
Information by business segment and geographic area
Revenue	(721,463)	(438,238)	(350,041)
Transfer-pricing adjustment | Mining
Information by business segment and geographic area
Revenue	(273,409)	(161,676)	(125,912)
Intersegment elimination excluding transfer-pricing adjustment | Mining
Information by business segment and geographic area
Revenue	(448,054)	(276,562)	(225,129)
Adjustments
Information by business segment and geographic area
Revenue	5,719	3,666	23,213
Cost of products sold	(123,311)	(103,685)	(110,689)
Gross profit	(117,592)	(100,019)	(87,476)
Sales of concentrate from smelting segment
Information by business segment and geographic area
Revenue	5,740	7,153	17,945
VMZ Energy sales
Information by business segment and geographic area
Revenue			8,354
Cost of concentrate sold by smelting segment
Information by business segment and geographic area
Cost of products sold	(3,303)	(2,405)	(10,968)
Cost of energy sold by VMZ
Information by business segment and geographic area
Cost of products sold			(4,788)
Employee compensation - production performance
Information by business segment and geographic area
Cost of products sold	(33,969)	(31,602)	(21,825)
Amortization of purchase price allocation of Milpo
Information by business segment and geographic area
Cost of products sold	(77,585)	(77,585)	(77,672)
Fair value hedge
Information by business segment and geographic area
Cost of products sold	(8,406)	14,729	(6,230)
Other adjustments
Information by business segment and geographic area
Revenue	(21)	(3,487)	(3,086)
Cost of products sold	$ (48)	$ (6,822)	$ 10,794

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Information by business segment and geographic area - Segment adjusted EBITDA (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Information by business segment and geographic area
Segment Adjusted EBITDA	$ 674,283	$ 407,324	$ 481,559
Extraordinary items:
Gain on sale of investment	4,588	408
Impairment of other assets	(73)	(308)
(Reversal) Impairment - property, plant, equipment		979	(8,574)
Other	(6,764)	(3,400)	(13,797)
Results of investees	60	(158)	(256)
Depreciation, amortization and depletion	(270,454)	(275,034)	(295,258)
Net financial results	(130,181)	79,081	(341,931)
Taxes on income	(106,194)	(98,383)	38,779
Discontinued operations			(318)
Profit (loss) for the year	165,265	110,509	(139,796)
Mining
Information by business segment and geographic area
Segment Adjusted EBITDA	521,544	336,796	221,791
Smelting
Information by business segment and geographic area
Segment Adjusted EBITDA	$ 152,739	$ 70,528	$ 259,768

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Information by business segment and geographic area - Information by geographic area (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Information by business segment and geographic area
Net revenue from products sold	$ 2,449,484	$ 1,964,841	$ 1,865,183
Cost of products sold	(1,681,202)	(1,439,101)	(1,463,290)
Gross profit	768,282	525,740	401,893
Brazil
Information by business segment and geographic area
Net revenue from products sold	1,003,804	727,462	665,573
Cost of products sold	(670,964)	(484,851)	(460,284)
Gross profit	332,840	242,611	205,289
Property, plant and equipment and intangible assets	1,025,291	851,465
Peru
Information by business segment and geographic area
Net revenue from products sold	1,445,680	1,237,379	1,199,610
Cost of products sold	(1,010,238)	(954,250)	(1,003,006)
Gross profit	435,442	283,129	$ 196,604
Property, plant and equipment and intangible assets	2,792,285	3,025,199
Other countries
Information by business segment and geographic area
Property, plant and equipment and intangible assets	$ 1,657	$ 2,322

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Defined contribution pension plans (Details)	12 Months Ended
	Dec. 31, 2017
Defined contribution pension plans.
Period for additional salary as compensation for time of service	1 month
Maximum
Defined contribution pension plans.
Percentage of monthly remuneration matched, contributions for employees with lower remuneration	1.50%
Percentage of monthly remuneration matched, contributions for employees with higher remuneration	6.00%

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Insurance coverage (Details) $ in Thousands	Dec. 31, 2017 USD ($)
Insurance coverage
Facilities, equipment and products in inventory, insured amount	$ 3,234,169
Loss of profits, insured amount	$ 778,735

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Subsequent events (Details) - USD ($) $ / shares in Units, $ in Thousands		12 Months Ended
	Mar. 28, 2018	Dec. 31, 2017	Dec. 31, 2016	Feb. 15, 2018
Subsequent events
Payments for Reimbursement of Share Premium		$ 430,000	$ 69,931
Reimbursement of share premium
Subsequent events
Reimbursement of share premium per share (in dollars per share)				$ 0.60
Payments for Reimbursement of Share Premium	$ 80,000