10-Q

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM 10-Q

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

For the quarterly period ended March 31, 2023

or

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

For the transition period from _______________________ to __________________________

Commission File Number 001-31921

Compass Minerals International, Inc.

(Exact name of registrant as specified in its charter)

Delaware	36-3972986
(State or other jurisdiction of  incorporation or organization)	(I.R.S. Employer Identification Number)

9900 West 109th Street

Suite 100

Overland Park, KS 66210

(913) 344-9200

(Address of principal executive offices, zip code and telephone number, including area code)

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

Title of each class	Trading Symbol	Name of each exchange on which registered
Common stock, $0.01 par value	CMP	The New York Stock Exchange

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	☑	No	☐

Indicate by check mark whether the registrant has submitted electronically every Interactive Data File required to be submitted 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 such files)	Yes	☑	No	☐

Indicate by check mark whether the registrant is a large accelerated filer, an accelerated filer, a non-accelerated filer, a smaller reporting company, or an emerging growth company. See the definitions of “large accelerated filer,” “accelerated filer,” “smaller reporting company,” and “emerging growth company” in Rule 12b-2 of the Exchange Act.
Large accelerated filer	☑	Accelerated filer	☐	Non-accelerated filer	☐	Smaller reporting company	☐
						Emerging growth company	☐

If an emerging growth company, 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. ☐

Indicate by check mark whether the registrant is a shell company (as defined in Rule 12b-2 of the Exchange Act). Yes ☐ No ☑

The number of shares outstanding of the registrant’s common stock, $0.01 par value per share, as of May 5, 2023, was 41,139,343 shares.

COMPASS MINERALS INTERNATIONAL, INC.

TABLE OF CONTENTS

	PART I. FINANCIAL INFORMATION	Page
Item 1.	Financial Statements
	Consolidated Balance Sheets as of March 31, 2023 (unaudited) and September 30, 2022	2
	Consolidated Statements of Operations for the three and six months ended March 31, 2023 and 2022 (unaudited)	3
	Consolidated Statements of Comprehensive Loss for the three and six months ended March 31, 2023 and 2022 (unaudited)	4
	Consolidated Statements of Stockholders’ Equity for the three and six months ended March 31, 2023 and 2022 (unaudited)	5
	Consolidated Statements of Cash Flows for the six months ended March 31, 2023 and 2022 (unaudited)	6
	Notes to Consolidated Financial Statements (unaudited)	7
Item 2.	Management’s Discussion and Analysis of Financial Condition and Results of Operations	25
Item 3.	Quantitative and Qualitative Disclosures about Market Risk	39
Item 4.	Controls and Procedures	40
	PART II. OTHER INFORMATION
Item 1.	Legal Proceedings	41
Item 1A.	Risk Factors	41
Item 2.	Unregistered Sales of Equity Securities and Use of Proceeds	41
Item 3.	Defaults Upon Senior Securities	42
Item 4.	Mine Safety Disclosures	42
Item 5.	Other Information	42
Item 6.	Exhibits	42
SIGNATURES		43

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Table of Contents COMPASS MINERALS INTERNATIONAL, INC.

PART I. FINANCIAL INFORMATION

Item 1.    Financial Statements

CONSOLIDATED BALANCE SHEETS

(in millions, except share data)

	(Unaudited)
	March 31, 2023		September 30, 2022
ASSETS
Current assets:
Cash and cash equivalents	$	249.7	$	46.1
Receivables, less allowance for doubtful accounts of $3.1 at March 31, 2023 and $3.4 at September 30, 2022	159.7		167.2
Inventories	261.7		304.4
Other	29.7		44.3
Total current assets	700.8		562.0
Property, plant and equipment, net	782.6		776.6
Intangible assets, net	44.9		45.4
Goodwill	56.9		56.4
Equity method investments	44.3		46.6
Other	155.2		156.5
Total assets	$	1,784.7	$	1,643.5
LIABILITIES AND STOCKHOLDERS’ EQUITY
Current liabilities:
Current portion of long-term debt	$	—	$	—
Accounts payable	114.9		114.7
Accrued salaries and wages	18.7		22.2
Income taxes payable	51.1		1.0
Accrued interest	14.1		14.1
Accrued expenses and other current liabilities	77.2		81.1
Total current liabilities	276.0		233.1
Long-term debt, net of current portion	825.7		947.6
Deferred income taxes, net	60.7		63.4
Other noncurrent liabilities	136.9		143.0
Commitments and contingencies (Note 10)
Stockholders’ equity:
Common stock: $0.01 par value, 200,000,000 authorized shares; 42,197,964 issued shares at March 31, 2023 and 35,367,264 issued shares at September 30, 2022	0.4		0.4
Additional paid-in capital	406.2		152.1
Treasury stock, at cost — 1,058,621 shares at March 31, 2023 and 1,196,300 shares at September 30, 2022	(8.6)		(7.3)
Retained earnings	192.0		226.5
Accumulated other comprehensive loss	(104.6)		(115.3)
Total stockholders’ equity	485.4		256.4
Total liabilities and stockholders’ equity	$	1,784.7	$	1,643.5

The accompanying notes are an integral part of the consolidated financial statements.

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CONSOLIDATED STATEMENTS OF OPERATIONS

(Unaudited, in millions, except share and per share data)

	Three Months Ended March 31,				Six Months Ended March 31,
	2023		2022		2023		2022
Sales	$	411.1	$	448.5	$	763.5	$	780.0
Shipping and handling cost	130.1		160.1		237.5		255.8
Product cost	195.8		223.8		370.8		399.7
Gross profit	85.2		64.6		155.2		124.5
Selling, general and administrative expenses	37.3		44.6		79.4		84.1
Operating earnings	47.9		20.0		75.8		40.4
Other (income) expense:
Interest income	(1.9)		—		(3.0)		(0.3)
Interest expense	14.2		13.9		28.1		27.8
(Gain) loss on foreign exchange	(0.2)		3.0		2.3		2.6
Net loss in equity investee	1.4		1.7		2.3		2.1
Other expense, net	0.9		—		1.0		0.1
Earnings from continuing operations before income taxes	33.5		1.4		45.1		8.1
Income tax expense from continuing operations	55.1		30.4		67.0		29.2
Net loss from continuing operations	(21.6)		(29.0)		(21.9)		(21.1)
Net earnings from discontinued operations	—		16.9		—		11.4
Net loss	$	(21.6)	$	(12.1)	$	(21.9)	$	(9.7)
Basic net loss from continuing operations per common share	$	(0.53)	$	(0.85)	$	(0.55)	$	(0.62)
Basic net earnings from discontinued operations per common share	—		0.49		—		0.33
Basic net loss per common share	$	(0.53)	$	(0.36)	$	(0.55)	$	(0.29)
Diluted net loss from continuing operations per common share	$	(0.53)	$	(0.85)	$	(0.55)	$	(0.62)
Diluted net earnings from discontinued operations per common share	—		0.49		—		0.33
Diluted net loss per common share	$	(0.53)	$	(0.36)	$	(0.55)	$	(0.29)
Weighted-average common shares outstanding (in thousands):
Basic	41,110		34,103		40,423		34,081
Diluted	41,110		34,113		40,423		34,100

The accompanying notes are an integral part of the consolidated financial statements.

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CONSOLIDATED STATEMENTS OF COMPREHENSIVE LOSS

(Unaudited, in millions)

	Three Months Ended March 31,				Six Months Ended March 31,
	2023		2022		2023		2022
Net loss	$	(21.6)	$	(12.1)	$	(21.9)	$	(9.7)
Other comprehensive income (loss):
Unrealized gain from change in pension obligations, net of tax of $0.0 for the three and six months ended March 31, 2023 and 2022	—		0.1		0.1		0.2
Unrealized (loss) gain on cash flow hedges, net of tax of $0.0 and $(0.3) for the three and six months ended March 31, 2023, respectively, and $0.4 for both the three and six months ended March 31, 2022	(1.1)		1.0		(3.9)		(1.0)
Cumulative translation adjustment	2.8		10.7		14.5		6.9
Comprehensive loss	$	(19.9)	$	(0.3)	$	(11.2)	$	(3.6)

The accompanying notes are an integral part of the consolidated financial statements.

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CONSOLIDATED STATEMENTS OF STOCKHOLDERS’ EQUITY

For the three and six months ended March 31, 2023 and 2022

(Unaudited, in millions)

	Common Stock		Additional Paid-In Capital		Treasury Stock		Retained Earnings		Accumulated Other Comprehensive (Loss) Income		Total
Balance, September 30, 2022	$	0.4	$	152.1	$	(7.3)	$	226.5	$	(115.3)	$	256.4
Comprehensive (loss) income	—		—		—		(0.3)		9.0		8.7
Dividends on common stock ($0.15 per share)	—		—		—		(6.3)		—		(6.3)
Private placement of common stock	—		240.7		—		—		—		240.7
Shares issued for stock units, net of shares withheld for taxes	—		—		(0.3)		—		—		(0.3)
Stock-based compensation	—		10.6		—		—		—		10.6
Balance, December 31, 2022	$	0.4	$	403.4	$	(7.6)	$	219.9	$	(106.3)	$	509.8
Comprehensive (loss) income	—		—		—		(21.6)		1.7		(19.9)
Dividends on common stock ($0.15 per share)	—		—		—		(6.3)		—		(6.3)
Shares issued for stock units, net of shares withheld for taxes	—		(0.3)		(1.0)		—		—		(1.3)
Stock-based compensation	—		3.1		—		—		—		3.1
Balance, March 31, 2023	$	0.4	$	406.2	$	(8.6)	$	192.0	$	(104.6)	$	485.4

	Common Stock		Additional Paid-In Capital		Treasury Stock		Retained Earnings		Accumulated Other Comprehensive (Loss) Income		Total
Balance, September 30, 2021	$	0.4	$	136.3	$	(5.5)	$	272.4	$	(110.5)	$	293.1
Comprehensive income (loss)	—		—		—		2.4		(5.7)		(3.3)
Dividends on common stock ($0.15 per share)	—		(0.1)		—		(5.2)		—		(5.3)
Stock options exercised, net of shares withheld for taxes	—		0.2		—		—		—		0.2
Stock-based compensation	—		3.3		—		—		—		3.3
Balance, December 31, 2021	$	0.4	$	139.7	$	(5.5)	$	269.6	$	(116.2)	$	288.0
Comprehensive (loss) income	—		—		—		(12.1)		11.8		(0.3)
Dividends on common stock ($0.15 per share)	—		—		—		(5.2)		—		(5.2)
Shares issued for stock units, net of shares withheld for taxes	—		(0.1)		(0.4)		—		—		(0.5)
Stock-based compensation	—		4.5		—		—		—		4.5
Balance, March 31, 2022	$	0.4	$	144.1	$	(5.9)	$	252.3	$	(104.4)	$	286.5

The accompanying notes are an integral part of the consolidated financial statements.

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CONSOLIDATED STATEMENTS OF CASH FLOWS

(Unaudited, in millions)

	Six Months Ended March 31,
	2023		2022
Cash flows from operating activities:
Net loss	$	(21.9)	$	(9.7)
Adjustments to reconcile net loss to net cash flows provided by operating activities:
Depreciation, depletion and amortization	48.4		56.2
Amortization of deferred financing costs	1.5		1.5
Stock-based compensation	13.7		7.8
Deferred income taxes	(4.2)		16.2
Unrealized foreign exchange loss (gain)	2.3		(15.2)
Loss on impairment of long-lived assets	—		24.7
Net loss in equity investees	2.3		2.1
Other, net	2.4		1.0
Changes in operating assets and liabilities:
Receivables	8.9		(63.7)
Inventories	44.1		108.9
Other assets	18.4		(9.0)
Accounts payable and accrued expenses and other current liabilities	35.6		25.9
Other liabilities	(7.6)		(0.8)
Net cash provided by operating activities	143.9		145.9
Cash flows from investing activities:
Capital expenditures	(43.7)		(43.5)
Investments in equity method investees	—		(46.3)
Other, net	(0.3)		1.4
Net cash used in investing activities	(44.0)		(88.4)
Cash flows from financing activities:
Proceeds from revolving credit facility borrowings	16.7		221.3
Principal payments on revolving credit facility borrowings	(168.2)		(280.7)
Proceeds from issuance of long-term debt	37.5		50.8
Principal payments on long-term debt	(9.1)		(5.9)
Net proceeds from private placement of common stock	240.7		—
Dividends paid	(12.6)		(10.5)
Proceeds from stock options exercised	—		0.2
Shares withheld to satisfy employee tax obligations	(1.6)		(0.5)
Other, net	(0.5)		(0.6)
Net cash provided by (used in) financing activities	102.9		(25.9)
Effect of exchange rate changes on cash and cash equivalents	0.8		2.4
Net change in cash and cash equivalents	203.6		34.0
Cash and cash equivalents, beginning of the year	46.1		21.0
Cash and cash equivalents, end of period	249.7		55.0
Less: cash and cash equivalents included in current assets held for sale	—		(10.1)
Cash and cash equivalents of continuing operations, end of period	$	249.7	$	44.9

Supplemental cash flow information:
Interest paid, net of amounts capitalized	$	26.5	$	26.7
Income taxes paid, net of refunds	$	14.0	$	13.1

The accompanying notes are an integral part of the consolidated financial statements.

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NOTES TO CONSOLIDATED FINANCIAL STATEMENTS

(Unaudited)

1.    Accounting Policies and Basis of Presentation:

Compass Minerals International, Inc. (“CMI”), through its subsidiaries (collectively, the “Company”), is a leading global provider of essential minerals focused on safely delivering where and when it matters to help solve nature’s challenges for customers and communities. The Company’s salt products help keep roadways safe during winter weather and are used in numerous other consumer, industrial, chemical and agricultural applications. Its plant nutrition business is the leading North American producer of sulfate of potash (“SOP”), which is used in the production of specialty fertilizers for high-value crops and turf and helps improve the quality and yield of crops, while supporting sustainable agriculture. The Company’s principal products are salt, consisting of sodium chloride and magnesium chloride, and SOP. Additionally, the Company is pursuing development of a sustainable lithium brine resource to support the North American battery market and is a minority owner of Fortress North America, LLC (“Fortress”), a next-generation fire retardant company (See Note 7, for a discussion of the subsequent acquisition of the remaining Fortress ownership interests). The Company’s production sites are located in the United States (“U.S.”), Canada and the United Kingdom (“U.K.”). The Company also provides records management services to businesses located in the U.K. Except where otherwise noted, references to North America include only the continental U.S. and Canada, and references to the U.K. include only England, Scotland and Wales. References to “Compass Minerals,” “our,” “us” and “we” refer to CMI and its consolidated subsidiaries.

CMI is a holding company with no significant operations other than those of its wholly-owned subsidiaries. The consolidated financial statements include the accounts of CMI and its wholly-owned domestic and foreign subsidiaries. All significant intercompany balances and transactions have been eliminated in consolidation.

The accompanying unaudited consolidated financial statements have been prepared in accordance with U.S. generally accepted accounting principles (“U.S. GAAP”) for interim financial information and with the instructions to Form 10-Q and Article 10 of Regulation S-X. Accordingly, they do not include all of the information and footnotes required by U.S. GAAP for complete consolidated financial statements. These unaudited consolidated financial statements should be read in conjunction with the consolidated financial statements of the Company for the annual period ended September 30, 2022, as filed with the Securities and Exchange Commission (the “SEC”) in its Annual Report on Form 10-K on December 14, 2022. In the opinion of management, all adjustments, consisting of normal recurring adjustments considered necessary for a fair presentation, have been included.

The Company experiences a substantial amount of seasonality in its sales, including its deicing salt product sales. As a result, Salt segment sales and operating income are generally higher in the first and second fiscal quarters (ending December 31 and March 31) and lower during the third and fourth fiscal quarters (ending June 30 and September 30) of each year. In particular, sales of highway and consumer deicing salt and magnesium chloride products vary based on the severity of the winter conditions in areas where the products are used. Following industry practice in North America and the U.K., the Company seeks to stockpile sufficient quantities of deicing salt throughout the first, third and fourth fiscal quarters (ending December 31, June 30 and September 30) to meet the estimated requirements for the winter season. Production of deicing salt can also vary based on the severity or mildness of the preceding winter season. Due to the seasonal nature of the deicing product lines, operating results for the interim periods are not necessarily indicative of the results that may be expected for the full fiscal year. The Company’s plant nutrition business is also seasonal. As a result, the Company and its customers generally build inventories during the plant nutrition business’ low demand periods of the year (which are typically winter and summer, but can vary due to weather and other factors) to ensure timely product availability during the peak sales seasons (which are typically spring and autumn, but can also vary due to weather and other factors).

Significant Accounting Policies

The Company’s significant accounting policies are detailed in “Note 2 – Summary of Significant Accounting Policies” within Part II, Item 8 of its Annual Report on Form 10-K for the annual period ended September 30, 2022. The Company reports its financial results from discontinued operations and continuing operations separately to recognize the financial impact of disposal transactions apart from ongoing operations. Discontinued operations reporting occurs when a component or a group of components of an entity has been disposed or classified as held for sale and represents a strategic shift that has a major effect on the entity’s operations and financial results. In the Company’s Consolidated Statements of Cash Flows, the cash flows from discontinued operations are not separately classified. Unless otherwise indicated, amounts provided in these Notes pertain to continuing operations. See Note 2 for information on discontinued operations and Note 11 for information on the Company’s reportable segments.

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Recent Accounting Pronouncements

In October 2021, the Financial Accounting Standards Board issued Accounting Standards Update (“ASU”) 2021-08, “Business Combinations (Topic 805): Accounting for Contract Assets and Contract Liabilities from Contracts with Customers.” ASU 2021-08 requires the company acquiring contract assets and contract liabilities obtained in a business combination to recognize and measure them in accordance with Accounting Standards Codification 606, “Revenue from Contracts with Customers”. Following the acquisition date, the company acquiring the business should record related revenue as if it had originated the contracts. Before the update, contract assets and contract liabilities from acquired contracts were recognized by the acquiring company at fair value on the acquisition date. The amendments are effective for fiscal years beginning after December 15, 2022, including interim periods within those fiscal years. Early adoption is permitted, including in interim periods, for any financial statements that have not yet been issued. The Company early adopted these requirements, effective on January 1, 2023, with no material impact to its consolidated financial statements.

Strategic Evaluation and Plan to Sell Businesses

Following an evaluation of the strategic fit of certain of the Company’s businesses and subsequent restructuring of its former South American Plant Nutrition segment to enable separate sales processes for its chemicals and specialty plant nutrition businesses and equity investment in Fermavi Eletroquímica Ltda. (“Fermavi”), in fiscal 2021 the Company’s Board of Directors approved the plan to sell each of these businesses and the North America micronutrient business (the “Specialty Businesses”) with a goal of reducing the Company’s leverage and enabling increased focus on optimizing the Company’s core businesses.

The Company concluded that the sale of the Specialty Businesses represented a strategic shift for the Company that would have a material effect on its operations and financial results. Consequently, the Specialty businesses were reclassified as discontinued operations on the Consolidated Statements of Operations. See Note 2 for further discussion of the sales of these businesses.

Unless otherwise indicated, amounts provided in these Notes pertain to continuing operations.

2.    Discontinued Operations:

During fiscal 2021 the Company sold its South America specialty plant nutrition business and equity investment in Fermavi and its North America micronutrient business. In connection with the sale of its South America specialty plant nutrition business the Company received net cash of approximately $318.4 million with an additional earnout payment of up to R$88 million Brazilian reais. On April 7, 2022, the Company received the maximum earnout possible under the terms of the sale, or $18.5 million based on exchange rates at the time of receipt.

Also in fiscal 2021, the Company completed the sale of its North America micronutrient business for approximately $56.7 million and its investment in Fermavi for R$45 million Brazilian reais (including R$30 million Brazilian reais of deferred purchase price). The Company received gross proceeds of approximately $2.9 million and recorded a discounted deferred proceeds receivable of approximately $4.8 million (based on exchange rates at the time of closing). As of March 31, 2023 approximately R$22.5 million Brazilian reais of deferred proceeds remains outstanding.

On April 20, 2022, the Company completed the sale of its South America chemicals business to a subsidiary of Cape Acquisitions LLC. Upon closing of the all-cash sale, the Company received gross proceeds of approximately $51.5 million based on exchange rates at the time of receipt, including a post-closing adjustment and compensation of $6.4 million for cash on hand that transferred to the buyer. The Company also paid fees of $2.4 million related to this sale. The Company recognized a loss recovery of $1.6 million during the three months ended June 30, 2022, an incremental loss from the sale of $23.1 million during the nine months ended June 30, 2022 and released $49.5 million from accumulated currency translation adjustment (“CTA”). The sale included all of the Company’s remaining operations in Brazil, concluding its previously announced plan to exit the South American market.

In measuring the assets and liabilities held for sale at fair value less estimated costs to sell, the Company completed an impairment analysis when its Board of Directors committed to a plan to sell the Specialty Businesses and the Company updated the analysis each quarter until each of the Specialty Businesses were sold.

The information below sets forth selected financial information related to the operating results of the Specialty Businesses classified as discontinued operations. The Specialty Businesses’ revenue and expenses have been reclassified to net earnings from discontinued operations in prior periods. The Consolidated Statements of Operations present the revenue and expenses that were reclassified from the specified line items to discontinued operations.

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The following table represents summarized Consolidated Statements of Operations information of discontinued operations (in millions):

	Three Months Ended March 31,			Six Months Ended March 31,
		2022			2022
Sales		$	24.3		$	46.7
Shipping and handling cost		1.3			2.5
Product cost		14.4			25.3
Gross profit		8.6			18.9
Selling, general and administrative expenses		1.4			3.0
Operating earnings		7.2			15.9
Interest expense		0.1			0.1
Gain on foreign exchange		(20.4)			(17.3)
Net loss on adjustment to fair value less estimated costs to sell		16.3			24.7
Other income, net		(0.3)			(0.5)
Earnings from discontinued operations before income taxes		11.5			8.9
Income tax benefit		(5.4)			(2.5)
Net earnings from discontinued operations		$	16.9		$	11.4

The significant components included in the Company’s Consolidated Statements of Cash Flows for discontinued operations are as follows (in millions):

	Six Months Ended March 31,
	2022
Loss on impairment of long-lived assets	$	24.7
Capital expenditures	(1.2)

3.    Revenues:

Nature of Products and Services

The Company’s Salt segment products include salt and magnesium chloride for use in road deicing and dust control, food processing, water softening, and agricultural and industrial applications. The Company’s Plant Nutrition segment produces and markets SOP in various grades worldwide to distributors and retailers of crop inputs, as well as growers and for industrial uses. In the U.K., the Company operates a records management business utilizing excavated areas of its Winsford salt mine with one other location in London, England.

Identifying the Contract

The Company accounts for a customer contract when there is approval and commitment from both parties, the rights of the parties and payment terms are identified, the contract has commercial substance and collectability of consideration is probable.

Identifying the Performance Obligations

At contract inception, the Company assesses the goods and services it has promised to its customers and identifies a performance obligation for each promise to transfer to the customer a distinct good or service (or bundle of goods or services). Determining whether products and services are considered distinct performance obligations that should be accounted for separately or aggregated together may require significant judgment.

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Identifying and Allocating the Transaction Price

The Company’s revenues are measured based on consideration specified in the customer contract, net of any sales incentives and amounts collected on behalf of third parties such as sales taxes. In certain cases, the Company’s customer contracts may include promises to transfer multiple products and services to a customer. For multiple-element arrangements, the Company generally allocates the transaction price to each performance obligation in proportion to its stand-alone selling price.

When Performance Obligations Are Satisfied

The vast majority of the Company’s revenues are recognized at a point in time when the performance obligations are satisfied based upon transfer of control of the product or service to a customer. To determine when the control of goods is transferred, the Company typically assesses, among other things, the shipping terms of the contract, as shipping is an indicator of transfer of control. Some of the Company’s products are sold when the control of the goods transfers to the customer at the time of shipment. There are also instances when the Company provides shipping services to deliver its products. Shipping and handling costs that occur before the customer obtains control of the goods are deemed to be fulfillment activities and are accounted for as fulfillment costs. The Company has made an accounting policy election to recognize any shipping and handling costs that are incurred after the customer obtains control of the goods as fulfillment costs which are accrued at the time of revenue recognition.

Significant Payment Terms

The customer contract states the final terms of the sale, including the description, quantity and price of each product or service purchased. Payment is typically due in full within 30 days of delivery. The Company does not adjust the consideration for the effects of a significant financing component if the Company expects, at contract inception, that the period between when the good or service is transferred to the customer and when the customer pays for that good or service will be one year or less.

Refunds, Returns and Warranties

The Company’s products are generally not sold with a right of return and the Company does not generally provide credits or incentives, which may be required to be accounted for as variable consideration when estimating the amount of revenue to be recognized. The Company uses historical experience to estimate accruals for refunds due to manufacturing or other defects.

See Note 11 for disaggregation of sales by segment, type and geographical region.

4.    Inventories:

Inventories consist of the following (in millions):

	March 31, 2023		September 30, 2022
Finished goods	$	203.8	$	251.6
Raw materials and supplies	57.9		52.8
Total inventories	$	261.7	$	304.4

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5.    Property, Plant and Equipment, Net:

Property, plant and equipment, net, consists of the following (in millions):

	March 31, 2023		September 30, 2022
Land, buildings and structures, and leasehold improvements	$	545.4	$	534.8
Machinery and equipment	1,071.1		1,026.3
Office furniture and equipment	58.6		56.8
Mineral interests	169.1		167.1
Construction in progress	57.2		64.3
	1,901.4		1,849.3
Less: accumulated depreciation and depletion	(1,118.8)		(1,072.7)
Property, plant and equipment, net	$	782.6	$	776.6

6.    Goodwill and Intangible Assets, Net:

Amounts related to the Company’s amortization of intangible assets are as follows (in millions):

	Three Months Ended March 31,				Six Months Ended March 31,
	2023		2022		2023		2022
Aggregate amortization expense	$	0.4	$	0.4	$	0.8	$	0.8

Amounts related to the Company’s goodwill are as follows (in millions):

	March 31, 2023		September 30, 2022
Plant Nutrition	$	51.0	$	50.9
Other	5.9		5.5
Total	$	56.9	$	56.4

The change in goodwill between September 30, 2022, and March 31, 2023 was due to the impact from translating foreign-denominated amounts to U.S. dollars. As of March 31, 2023, there were no indicators necessitating an interim impairment test of the Company’s reporting units based on the Company’s review of operating performance, among other factors, for the relevant reporting units.

7.    Equity Method Investments:

The Company uses the equity method of accounting for equity securities when it has significant influence or when it has more than a minor ownership interest or more than minor influence over an investee’s operations but does not have a controlling financial interest. Initial investments are recorded at cost (including certain transaction costs) and are adjusted by the Company’s share of the investees’ undistributed earnings and losses. The Company may recognize its share of an investee’s earnings on a lag if an investee’s financial results are not available in a timely manner.

For certain of the Company's equity method investments, such as investments where the capital structure of the equity investment results in different liquidation rights and priorities than what is reflected by the underlying percentage ownership interests, the Company's proportionate share of net earnings is accounted for using the Hypothetical Liquidation at Book Value ("HLBV") methodology available under the equity method of accounting. When applying HLBV, the Company determines the amount that would be received if the investee were to liquidate all of its assets and distribute the resulting cash to the investors based on contractually defined liquidation priorities, assuming the net assets were liquidated at their net book value.

The Company evaluates its equity method investments for impairment whenever events or changes in circumstances indicate that the carrying amounts of such investments may not be recoverable.

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On November 2, 2021, the Company announced an investment in Fortress, a next-generation fire retardant business dedicated to developing and producing a portfolio of magnesium chloride-based fire retardant products to help combat wildfires. As of March 31, 2023, the Company has invested $50 million in Fortress in exchange for an ownership interest of approximately 45%. Under the HLBV methodology available under the equity method of accounting, the Company reflects its share of the income or loss of Fortress in its results each period on a one quarter reporting lag. The Company recorded $1.0 million and $1.5 million for its share of Fortress’ net losses in the three and six months ended March 31, 2023, respectively, and $1.2 million and $1.3 million for its share of Fortress’ net losses in the three and six months ended March 31, 2022, respectively.

The carrying value of the Company’s equity investment in Fortress is in excess of its share of Fortress’s net book value by approximately $27 million as of March 31, 2023. The basis difference primarily represents incremental value attributable to intangible assets and goodwill that has not been recognized in the financial statements of Fortress. The Company has liquidation preference under the terms of Fortress’ LLC agreement. Additionally, the Company has the right to purchase units from other Fortress unit holders and the right of first refusal to purchase all or any portion of any available Fortress units, both subject to certain conditions.

The balance of the Company’s net investment in Fortress of $44.3 million and $45.8 million as of March 31, 2023 and September 30, 2022, respectively is recorded in equity method investments in the Consolidated Balance Sheets. The Company also has other immaterial equity investments valued at $0.0 million and $0.8 million as of March 31, 2023 and September 30, 2022, respectively, for which it has recorded $0.4 million and $0.8 million for its share of losses in the three and six months ended March 31, 2023, respectively, and $0.5 million and $0.8 million for its share of losses in the three and six months ended March 31, 2022, respectively.

On May 5, 2023, the Company acquired the remaining 55% interest in Fortress consisting of an initial cash payment of approximately $26 million, approximately $28 million to be paid in cash and/or Compass Minerals common stock upon the achievement of certain performance measures, and a cash earn-out based on volumes of certain Fortress fire retardant products sold over a 10-year period. Building upon the previous 45% minority ownership stake in Fortress, the transaction provides the Company full ownership of all Fortress assets, contracts, and intellectual property.

8.    Income Taxes:

The Company’s effective income tax rate differs from the U.S. statutory federal income tax rate primarily due to U.S. statutory depletion, state income taxes (net of federal tax benefit), nondeductible executive compensation over $1 million, foreign income, mining and withholding taxes, base erosion and anti-abuse tax, and valuation allowances recorded on deferred tax assets. For the six months ended March 31, 2022, there were also interest expense recognition differences for book and tax purposes.

Management assesses the available positive and negative evidence to estimate whether sufficient future taxable income will be generated to permit use of the existing deferred tax assets. A significant piece of objective negative evidence evaluated was the cumulative loss incurred in the U.S. over the three-year period ended March 31, 2023. Such objective evidence limits the ability to consider other subjective evidence, such as the Company’s projections for future income. On the basis of this evaluation, during the six months ended March 31, 2023, an additional valuation allowance of $15.8 million has been recorded to recognize only the portion of the U.S. deferred tax assets that is more likely than not to be realized. The amount of the deferred tax assets considered realizable, however, could be adjusted if estimates of future taxable income during the carryforward period are increased or reduced or if objective negative evidence in the form of cumulative losses is no longer present and additional weight is given to subjective evidence such as the Company’s projections for income.

As of March 31, 2023, and September 30, 2022, the Company had $82.1 million and $94.1 million, respectively of gross foreign federal NOL carryforwards that have no expiration date and $3.8 million and $3.2 million, respectively of net operating tax-effected state NOL carryforwards which expire beginning in 2035.

Canadian provincial tax authorities have challenged tax positions claimed by one of the Company’s Canadian subsidiaries and have issued tax reassessments for fiscal years 2002-2017. The reassessments are a result of ongoing audits and total $173.1 million, including interest, through March 31, 2023. The Company disputes these reassessments and will continue to work with the appropriate authorities in Canada to resolve the dispute. There is a reasonable possibility that the ultimate resolution of this dispute, and any related disputes for other open tax years, may be materially higher or lower than the amounts the Company has reserved for such disputes. In connection with this dispute, local regulations require the Company to post security with the tax authority until the dispute is resolved. The Company has posted collateral in the form of a $143.6 million performance bond and

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has paid $36.7 million to the Canadian tax authorities (most of which is recorded in other assets in the Consolidated Balance Sheets at March 31, 2023, and September 30, 2022), which is necessary to proceed with future appeals or litigation.

The Company expects that it will be required by local regulations to provide security for additional interest on the above unresolved disputed amounts and for any future reassessments issued by these Canadian tax authorities in the form of cash, letters of credit, performance bonds, asset liens or other arrangements agreeable with the tax authorities until the disputes are resolved.

The Company expects that the ultimate outcome of these matters will not have a material impact on its results of operations or financial condition. However, the Company can provide no assurance as to the ultimate outcome of these matters, and the impact could be material if they are not resolved in the Company’s favor. As of March 31, 2023, the Company believes it has adequately reserved for these reassessments.

Additionally, the Company has other uncertain tax positions as well as assessments and disputed positions with taxing authorities in its various jurisdictions, which are consistent with those matters disclosed in the Company’s Annual Report on Form 10-K for the annual period ended September 30, 2022.

9.    Long-Term Debt:

Long-term debt consists of the following (in millions):

	March 31, 2023		September 30, 2022
4.875% Senior Notes due July 2024	$	250.0	$	250.0
Term Loan due January 2025	16.9		16.9
Revolving Credit Facility due January 2025	—		151.5
6.75% Senior Notes due December 2027	500.0		500.0
AR Securitization Facility expires June 2025	65.9		37.5
	832.8		955.9
Less unamortized debt issuance costs	(7.1)		(8.3)
Total debt	825.7		947.6
Less current portion	—		—
Long-term debt	$	825.7	$	947.6

As of March 31, 2023, the term loan and revolving credit facility under the Company’s credit agreement entered into on November 26, 2019 (as amended, the “2019 Credit Agreement”) were secured by substantially all existing and future U.S. assets of the Company, the Goderich mine in Ontario, Canada and capital stock of certain subsidiaries. As of March 31, 2023, the weighted average interest rate on all borrowings outstanding under the term loan under the Credit Agreement was approximately 6.9%.

The Company is in compliance as of March 31, 2023 with its debt covenants under the Credit Agreement and its AR Securitization Facility. Pursuant to the terms of the second amendment to the Credit Agreement the maximum allowed consolidated total net leverage ratio (as defined and calculated under the terms of the Credit Agreement and discussed further below) was 5.0x for the quarter ended March 31, 2023, which steps down to 4.75x in the quarter ending March 31, 2024, and to 4.5x for the fiscal quarter ended June 30, 2024 and thereafter. The consolidated total net leverage ratio represents the ratio of (a) consolidated total net debt to (b) consolidated adjusted earnings before interest, taxes, depreciation and amortization (“EBITDA”). Consolidated total net debt includes the aggregate principal amount of total debt, net of unrestricted cash not to exceed $50.0 million.

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In November 2022, the Company entered into the third amendment to the 2019 Credit Agreement, principally to affect a transition from the London Inter-Bank Offered Rate to the Secured Overnight Financing Rate pricing benchmark provisions.

During the quarter ended December 31, 2022, the Company paid off the outstanding revolving credit facility balance utilizing proceeds from a private placement of common stock. Refer to Note 12 for additional details of the private placement transaction.

In January 2023, certain of the Company’s U.S. subsidiaries entered into the second amendment to the AR Securitization Facility with PNC Bank, which temporarily eases the restrictions of certain covenants contained in the agreement through March 2023. The amendment made certain adjustments to the financial tests including: (i) the default ratio and (ii) the delinquency ratio to make compliance with such tests more likely.

On May 5, 2023, the Company entered into an agreement to amend and restate the 2019 Credit Agreement (as in effect prior to such restatement, the “Existing Credit Agreement”) with a new $575 million senior secured credit agreement due May 5, 2028 (as amended, the “2023 Credit Agreement”), comprised of a $375 million revolving credit facility and a $200 million term loan. The term loan is payable in quarterly installments of interest and principal beginning September 30, 2023. The 2023 Credit Agreement increases the Applicable Margins by 25 basis points over those defined in the Existing Credit Agreement and adds an additional level at a consolidated total leverage ratio of greater than 4:00 to 1.00. Consolidated total net debt includes the aggregate principal amount of total debt, net of unrestricted cash, which was increased from $50.0 million to $75 million, in the 2023 Credit Agreement. Proceeds from the 2023 Credit Agreement will be used by the Company to redeem its $250 million 4.875% Senior Notes on May 10, 2023 and pay off the Existing Credit Agreement term loan balance of $16.9 million.

The 2023 Credit Agreement, among other things, amends and restates the Existing Credit Agreement to (i) increase the Revolving Commitments (as defined in the Existing Credit Agreement) from $300 million to $375 million and extend the maturity date of the Revolving Commitments to May 5, 2028, (ii) refinance the Term Loans (as defined in the Existing Credit Agreement) with a new tranche of term loans in an aggregate principal amount equal to $200 million having a maturity date of May 5, 2028, and (iii) amend certain other terms of the Existing Credit Agreement, including, but not limited to, (a) expressly permit “run rate” cost savings in “Consolidated Adjusted EBITDA” (as defined in the Existing Credit Agreement) and (b) revise select covenants in the Existing Credit Agreement to, among other things, allow for Lithium Transactions (as defined below).

The 2023 Credit Agreement will permit, on the terms and conditions set forth therein, the entry into, and consummation of, lithium development joint ventures, projects or similar arrangements by any Lithium Subsidiary (as defined below), and any related funding transactions in connection therewith (collectively, the “Lithium Transactions”). A “Lithium Subsidiary” shall mean (a) Compass Minerals Lithium Corp of America Inc., a Delaware corporation, or any successor thereto and (b) (x) any newly-formed domestic subsidiary that is a wholly-owned Subsidiary of the Company (each of which will become a Subsidiary Guarantor (as defined in the Existing Credit Agreement)) and/or (y) any newly-formed domestic subsidiary that is not a wholly-owned subsidiary of the Company (each of which may, but shall not be required to become, at the option of the Company, a Subsidiary Guarantor), in each case formed in order to effectuate the Lithium Transactions.

The 2023 Credit Agreement is secured by substantially all existing and future U.S. assets of the Company, the Goderich mine in Ontario, Canada and capital stock of certain subsidiaries. The Term Loan requires the Company to maintain certain financial ratios, including a minimum interest coverage ratio and a maximum total net leverage ratio.

10.    Commitments and Contingencies:

As previously disclosed, the Company was the subject of an investigation by the Division of Enforcement of the SEC regarding the Company’s disclosures primarily concerning the operation of the Goderich mine, the former South American businesses, and related accounting and internal control matters including Salt interim inventory valuation methodology issues that were disclosed in the Company’s Form 10-K/A for the year ended December 31, 2020, and Form 10-Q/A for the quarter ended March 31, 2021, each filed with the SEC on September 3, 2021.

On September 23, 2022, the Company reached a settlement with the SEC, concluding and resolving the SEC investigation in its entirety. Under the terms of the settlement, the Company, without admitting or denying the findings in the administrative order issued by the SEC, agreed to pay a civil penalty of $12 million and to cease and desist from violations of specified provisions of the federal securities laws and rules promulgated thereunder, and to retain an independent compliance consultant for a period of approximately one year to review certain accounting practices and procedures. As set forth in the administrative order, the $12 million civil penalty is to be paid in installments: $2 million, which was paid on September 29, 2022, and $10 million to be paid no later than September 30, 2023. The Company previously recorded an accrual for the full amount of the penalty in the

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third quarter of fiscal 2022, which is reflected in accrued expenses and other current liabilities on the Company’s Consolidated Balance Sheets.

The Company is also involved in legal and administrative proceedings and claims of various types from the ordinary course of the Company’s business.

Management cannot predict the outcome of legal claims and proceedings with certainty. Nevertheless, management believes that the outcome of legal proceedings and claims, which are pending or known to be threatened, even if determined adversely, will not, individually or in the aggregate, have a material adverse effect on the Company’s results of operations, cash flows or financial position, except as otherwise described in Note 8 and this Note 10.

11.    Operating Segments:

The Company’s reportable segments are strategic business units that offer different products and services, and each business requires different technology and marketing strategies. In connection with the executed business disposals discussed in Note 1 and Note 2, the Company has identified two reportable segments. The Specialty Businesses that comprised the Company’s former Plant Nutrition South America reportable segment and the North America micronutrient product business previously reported within the former Plant Nutrition North America reportable segment were classified as discontinued operations for all periods presented in its consolidated financial statements in this Quarterly Report on Form 10-Q.

For the three and six months ended March 31, 2023 and 2022, the Company has presented two reportable segments in its Consolidated Financial Statements: Salt and Plant Nutrition. The Salt segment produces and markets salt, consisting of sodium chloride and magnesium chloride, for use in road deicing for winter roadway safety and for dust control, food processing, water softening and other consumer, agricultural and industrial applications. The Plant Nutrition segment produces and markets various grades of SOP.

Segment information is as follows (in millions):

Three Months Ended March 31, 2023	Salt		Plant Nutrition		Corporate & Other(a)(b)(c)		Total
Sales to external customers	$	360.5	$	47.7	$	2.9	$	411.1
Intersegment sales	—		1.4		(1.4)		—
Shipping and handling cost	124.0		6.1		—		130.1
Operating earnings (loss)(b)(c)	73.1		(0.7)		(24.5)		47.9
Depreciation, depletion and amortization	14.8		8.1		1.6		24.5
Total assets (as of end of period)	924.1		472.7		387.9		1,784.7

Three Months Ended March 31, 2022	Salt		Plant Nutrition		Corporate & Other(a)(b)		Total
Sales to external customers	$	391.3	$	54.3	$	2.9	$	448.5
Intersegment sales	—		0.7		(0.7)		—
Shipping and handling cost	153.4		6.7		—		160.1
Operating earnings (loss)(b)	49.3		4.4		(33.7)		20.0
Depreciation, depletion and amortization	16.2		8.8		2.9		27.9
Total assets (as of end of period)	925.4		444.4		266.4		1,636.2

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Six Months Ended March 31, 2023	Salt		Plant Nutrition		Corporate & Other(a)(b)(c)		Total
Sales to external customers	$	668.6	$	89.3	$	5.6	$	763.5
Intersegment sales	—		4.3		(4.3)		—
Shipping and handling cost	226.7		10.8		—		237.5
Operating earnings (loss)(b)(c)	120.2		10.3		(54.7)		75.8
Depreciation, depletion and amortization	28.7		16.4		3.3		48.4

Six Months Ended March 31, 2022	Salt		Plant Nutrition		Corporate & Other(a)(b)		Total
Sales to external customers	$	665.2	$	108.9	$	5.9	$	780.0
Intersegment sales	—		3.1		(3.1)		—
Shipping and handling cost	241.8		14.0		—		255.8
Operating earnings (loss)(b)	88.7		13.9		(62.2)		40.4
Depreciation, depletion and amortization	32.4		17.6		6.2		56.2

Disaggregated revenue by product type is as follows (in millions):

Three Months Ended March 31, 2023	Salt		Plant Nutrition		Corporate & Other(a)		Total
Highway Deicing Salt	$	273.7	$	—	$	—	$	273.7
Consumer & Industrial Salt	86.8		—		—		86.8
SOP	—		49.1		—		49.1
Eliminations & Other	—		(1.4)		2.9		1.5
Sales to external customers	$	360.5	$	47.7	$	2.9	$	411.1

Three Months Ended March 31, 2022	Salt		Plant Nutrition		Corporate & Other(a)		Total
Highway Deicing Salt	$	300.1	$	—	$	—	$	300.1
Consumer & Industrial Salt	91.2		—		—		91.2
SOP	—		55.0		—		55.0
Eliminations & Other	—		(0.7)		2.9		2.2
Sales to external customers	$	391.3	$	54.3	$	2.9	$	448.5

Six Months Ended March 31, 2023	Salt		Plant Nutrition		Corporate & Other(a)		Total
Highway Deicing Salt	$	464.0	$	—	$	—	$	464.0
Consumer & Industrial Salt	204.6		—		—		204.6
SOP	—		93.6		—		93.6
Eliminations & Other	—		(4.3)		5.6		1.3
Sales to external customers	$	668.6	$	89.3	$	5.6	$	763.5

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Six Months Ended March 31, 2022	Salt		Plant Nutrition		Corporate & Other(a)		Total
Highway Deicing Salt	$	463.8	$	—	$	—	$	463.8
Consumer & Industrial Salt	201.4		—		—		201.4
SOP	—		112.0		—		112.0
Eliminations & Other	—		(3.1)		5.9		2.8
Sales to external customers	$	665.2	$	108.9	$	5.9	$	780.0

(a)Corporate and Other includes corporate entities, records management operations, equity method investments, lithium development costs and other incidental operations and eliminations. Operating earnings (loss) for corporate and other includes indirect corporate overhead, including costs for general corporate governance and oversight, lithium-related expenses, as well as costs for the human resources, information technology, legal and finance functions.

(b)Corporate operating results for the three and six months ended March 31, 2023 include net reimbursements related to the settled SEC investigation of $0.4 million and $0.1 million, respectively. Corporate operating results for the three and six months ended March 31, 2022 include executive transition costs of $0.5 million and $3.8 million, respectively, and a contingent loss accrual and costs related to the SEC investigation of $13.6 million and $16.7 million, respectively. Refer to Note 10 for more information regarding the SEC investigation.

(c)In April 2023, the Company took initial steps to align its cost structure to its current business needs. These initiatives resulted in restructuring charges of $3.3 million, which impacted Corporate operating results for the three and six months ended March 31, 2023.

The Company’s revenue by geographic area is as follows (in millions):

	Three Months Ended March 31,				Six Months Ended March 31,
Revenue	2023		2022		2023		2022
United States(a)	$	283.1	$	327.8	$	531.3	$	549.1
Canada	101.0		104.5		188.6		193.9
United Kingdom	23.2		15.6		37.3		35.4
Other	3.8		0.6		6.3		1.6
Total revenue	$	411.1	$	448.5	$	763.5	$	780.0

(a)United States sales exclude product sold to foreign customers at U.S. ports.

12.    Stockholders’ Equity and Equity Instruments:

In May 2020, the Company’s stockholders approved the 2020 Incentive Award Plan (as amended, the “2020 Plan”), which authorized the issuance of 2,977,933 shares of Company common stock. In February 2022, the Company’s stockholders approved an amendment to the 2020 Plan authorizing an additional 750,000 shares of Company stock. Since the date the 2020 Plan was approved, the Company ceased issuing equity awards under the 2015 Incentive Award Plan (as amended, the “2015 Plan”). Since the approval of the 2015 Plan in May 2015, the Company ceased issuing equity awards under the 2005 Incentive Award Plan (as amended, the “2005 Plan”). The 2005 Plan, the 2015 Plan and the 2020 Plan allow for grants of equity awards to executive officers, other employees and directors, including restricted stock units (“RSUs”), performance stock units (“PSUs”), stock options and deferred stock units.

Koch Equity Investment

On September 14, 2022, the Company entered into a Stock Purchase Agreement with Koch Minerals & Trading, LLC (“KM&T”), a subsidiary of Koch Industries, Inc. (“KII”), pursuant to which the Company agreed to issue and sell 6,830,700 shares of its common stock at a purchase price of $36.87 for aggregate net proceeds of approximately $240.7 million, net of transaction costs. On October 18, 2022, the Company closed the direct private placement with KM&T, through its affiliate KM&T Investment Holdings, LLC, resulting in their ownership of approximately 17% of the Company’s outstanding common stock. The Company expects to use approximately $200 million of the proceeds from the private placement to advance the first development phase of its sustainable lithium development project at its Ogden site. The Company used the remaining approximately $40.7 million of proceeds to reduce debt.

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Options

Substantially all of the stock options granted vest ratably, in tranches, over a four-year service period. Unexercised options expire after seven years. Options do not have dividend or voting rights. Upon vesting, each option can be exercised to purchase one share of the Company’s common stock. The exercise price of options is equal to the closing stock price on the grant date.

To estimate the fair value of options on the grant date, the Company uses the Black-Scholes option valuation model. Award recipients are grouped according to expected exercise behavior. Unless better information is available to estimate the expected term of the options, the estimate is based on historical exercise experience. The risk-free rate, using U.S. Treasury yield curves in effect at the time of grant, is selected based on the expected term of each group. The Company’s historical stock price is used to estimate expected volatility.

RSUs

Typically, the RSUs granted under the 2015 Plan and the 2020 Plan vest after one to three years of service. RSUs entitle the holders to one share of common stock for each vested RSU. Unvested RSUs do not have voting rights but are entitled to receive non-forfeitable dividends (generally after a performance hurdle has been satisfied for the year of the grant) or other distributions equal to those declared on the Company’s common stock for RSUs that are earned as a result of the satisfaction of the performance hurdle. The closing stock price on the grant date is used to determine the fair value of RSUs.

PSUs

Substantially all of the PSUs outstanding under the 2015 Plan and the 2020 Plan are either total stockholder return PSUs (“TSR PSUs”) or adjusted EBITDA growth PSUs (“EBITDA Growth PSUs”). The actual number of shares of the Company’s common stock that may be earned with respect to TSR PSUs is calculated by comparing the Company’s total stockholder return to the total stockholder return for each company comprising the Company’s peer group or a total return percentage target over a two- or three-year performance period and may range from 0% to 300% of the target number of shares based upon the attainment of these performance conditions. The actual number of shares of common stock that may be earned with respect to EBITDA Growth PSUs is calculated based on the attainment of adjusted EBITDA growth during the performance period and may range from 0% to 300% of the target number of shares based upon the attainment of these performance conditions.

PSUs represent a target number of shares of the Company’s common stock that may be earned before adjustment based upon the attainment of certain performance conditions. Holders of PSUs do not have voting rights but are entitled to receive non-forfeitable dividends or other distributions equal to those declared on the Company’s common stock for PSUs that are earned, which are paid when the shares underlying the PSUs are issued.

To estimate the fair value of the TSR PSUs on the grant date for accounting purposes, the Company uses a Monte-Carlo simulation model, which simulates future stock prices of the Company as well as the Company’s peer group. This model uses historical stock prices to estimate expected volatility and the Company’s correlation to the peer group. The risk-free rate was determined using the same methodology as the option valuations as discussed above. The Company’s closing stock price on the grant date was used to estimate the fair value of the EBITDA Growth PSUs. The Company will adjust the expense of the EBITDA Growth PSUs based upon its estimate of the number of shares that will ultimately vest at each interim date during the vesting period.

During the six months ended March 31, 2023, the Company reissued the following number of shares from treasury stock: 115,123 shares related to the release of RSUs which vested and 58,287 shares related to stock payments. In fiscal 2022, the Company issued 117,390 net shares from treasury stock. The Company withheld a total of 35,731 shares with a fair value of $1.6 million related to the vesting of RSUs, PSUs, and stock payments during the six months ended March 31, 2023. The fair value of the shares was valued at the closing price at the vesting date and represent the employee tax withholding for the employee’s compensation. The Company recognized tax expense of $0.7 million from its equity compensation awards during the six months ended March 31, 2023. During the six months ended March 31, 2023 and 2022, the Company recorded $14.1 million and $9.2 million (includes $0.4 million and $1.4 million paid in cash), respectively, of compensation expense pursuant to its stock-based compensation plans. No amounts have been capitalized.

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The following table summarizes stock-based compensation activity during the six months ended March 31, 2023:

	Stock Options			RSUs			PSUs(a)
	Number	Weighted-average exercise price		Number	Weighted-average fair value		Number	Weighted-average fair value
Outstanding at September 30, 2022	774,580	$	60.68	208,735	$	63.02	331,359	$	71.51
Granted	—	—		238,075	38.29		183,974	68.33
Exercised(b)	—	—		—	—		—	—
Released from restriction(b)	—	—		(122,645)	61.80		—	—
Cancelled/expired	(24,962)	62.53		(12,501)	46.86		(109,276)	66.69
Outstanding at March 31, 2023	749,618	$	60.61	311,664	$	45.26	406,057	$	71.37

(a)Until the performance period is completed, PSUs are included in the table at the target level at their grant date and at that level represent one share of common stock per PSU.

(b)Common stock issued for exercised options and for vested and earned RSUs and PSUs was issued from treasury stock.

Accumulated Other Comprehensive Loss (“AOCL”)

The Company’s comprehensive income (loss) is comprised of net earnings (loss), net amortization of the unrealized loss of the pension obligation, the change in the unrealized gain in other postretirement benefits, the change in the unrealized gain (loss) on natural gas and foreign currency cash flow hedges and CTA. The components of and changes in AOCL are as follows (in millions):

Three Months Ended March 31, 2023(a)	Gains and (Losses) on Cash Flow Hedges		Defined Benefit Pension		Other Post-Employment Benefits		Foreign Currency		Total
Beginning balance	$	(4.4)	$	(2.6)	$	1.3	$	(100.6)	$	(106.3)
Other comprehensive (loss) income before reclassifications(b)	(1.8)		—		—		2.8		1.0
Amounts reclassified from AOCL	0.7		—		—		—		0.7
Net current period other comprehensive (loss) income	(1.1)		—		—		2.8		1.7
Ending balance	$	(5.5)	$	(2.6)	$	1.3	$	(97.8)	$	(104.6)

Three Months Ended March 31, 2022(a)	Gains and (Losses) on Cash Flow Hedges		Defined Benefit Pension		Foreign Currency		Total
Beginning balance	$	1.1	$	(5.3)	$	(112.0)	$	(116.2)
Other comprehensive income before reclassifications(b)	1.6		—		10.7		12.3
Amounts reclassified from AOCL	(0.6)		0.1		—		(0.5)
Net current period other comprehensive income	1.0		0.1		10.7		11.8
Ending balance	$	2.1	$	(5.2)	$	(101.3)	$	(104.4)

Six Months Ended March 31, 2023(a)	Gains and (Losses) on Cash Flow Hedges		Defined Benefit Pension		Other Post-Employment Benefits		Foreign Currency		Total
Beginning balance	$	(1.6)	$	(2.7)	$	1.3	$	(112.3)	$	(115.3)
Other comprehensive (loss) income before reclassifications(b)	(4.2)		—		—		14.5		10.3
Amounts reclassified from AOCL	0.3		0.1		—		—		0.4
Net current period other comprehensive (loss) income	(3.9)		0.1		—		14.5		10.7
Ending balance	$	(5.5)	$	(2.6)	$	1.3	$	(97.8)	$	(104.6)

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Six Months Ended March 31, 2022(a)	Gains and (Losses) on Cash Flow Hedges		Defined Benefit Pension		Foreign Currency		Total
Beginning balance	$	3.1	$	(5.4)	$	(108.2)	$	(110.5)
Other comprehensive income before reclassifications(b)	0.7		—		6.9		7.6
Amounts reclassified from AOCL	(1.7)		0.2		—		(1.5)
Net current period other comprehensive (loss) income	(1.0)		0.2		6.9		6.1
Ending balance	$	2.1	$	(5.2)	$	(101.3)	$	(104.4)

(a)With the exception of the CTA, for which no tax effect is recorded, the changes in the components of AOCL presented in the tables above are reflected net of applicable income taxes.

(b)The Company recorded foreign exchange (loss) of $(0.1) million and $(1.4) million in the three and six months ended March 31, 2023, respectively, and $(1.9) million and $(0.7) million in the three and six months ended March 31, 2022, respectively, in AOCL related to intercompany notes which were deemed to be of a long-term investment nature.

The amounts reclassified from AOCL to expense (income) for the three and six months ended March 31, 2023 and 2022, are shown below (in millions):

	Amount Reclassified from AOCL
	Three Months Ended March 31,				Six Months Ended March 31,				Line Item Impacted in the Consolidated Statements of Operations
	2023		2022		2023		2022
Loss (Gain) on cash flow hedges:
Natural gas instruments	$	1.0	$	(0.9)	$	0.5	$	(2.3)	Product cost
Income tax expense	(0.3)		0.3		(0.2)		0.6
Reclassifications, net of income taxes	0.7		(0.6)		0.3		(1.7)
Amortization of defined benefit pension:
Amortization of loss	—		0.1		0.1		0.2		Product cost
Income tax benefit	—		—		—		—
Reclassifications, net of income taxes	—		0.1		0.1		0.2
Amortization of other post-employment benefits:
Amortization of loss	—		—		—		—		Product cost
Income tax benefit	—		—		—		—
Reclassifications, net of income taxes	—		—		—		—
Total reclassifications, net of income taxes	$	0.7	$	(0.5)	$	0.4	$	(1.5)

13.    Derivative Financial Instruments:

The Company is subject to various types of market risks, including interest rate risk, foreign currency exchange rate transaction and translation risk and commodity pricing risk. Management may take actions to mitigate the exposure to these types of risks, including entering into forward purchase contracts and other financial instruments. The Company manages a portion of its commodity pricing risks and foreign currency exchange rate risks by using derivative instruments. From time to time, the Company may enter into foreign exchange contracts to mitigate foreign exchange risk. The Company does not seek to engage in trading activities or take speculative positions with any financial instrument arrangement. The Company has entered into natural gas derivative instruments and foreign currency derivative instruments with counterparties it views as creditworthy. However, the Company does attempt to mitigate its counterparty credit risk exposures by, among other things, entering into master netting agreements with some of these counterparties. The Company records derivative financial instruments as either assets or liabilities at fair value in its Consolidated Balance Sheets. The assets and liabilities recorded as of March 31, 2023 and September 30, 2022 were not material.

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Derivatives qualify for treatment as hedges when there is a high correlation between the change in fair value of the derivative instrument and the related change in value of the underlying hedged item. Depending on the exposure being hedged, the Company must designate the hedging instrument as a fair value hedge, a cash flow hedge or a net investment in foreign operations hedge. For the qualifying derivative instruments that have been designated as hedges, the effective portion of the change in fair value is recognized through earnings when the underlying transaction being hedged affects earnings, allowing a derivative’s gains and losses to offset related results from the hedged item in the Consolidated Statements of Operations. Any ineffectiveness related to these instruments accounted for as hedges was not material for any of the periods presented. For derivative instruments that have not been designated as hedges, the entire change in fair value is recorded through earnings in the period of change.

Natural Gas Derivative Instruments

Natural gas is consumed at several of the Company’s production facilities, and changes in natural gas prices impact the Company’s operating margin. The Company seeks to reduce the earnings and cash flow impacts of changes in market prices of natural gas by fixing the purchase price of up to 90% of its forecasted natural gas usage. It is the Company’s policy to consider hedging portions of its natural gas usage up to 36 months in advance of the forecasted purchase. As of March 31, 2023, the Company had entered into natural gas derivative instruments to hedge a portion of its natural gas purchase requirements through September 2024. As of March 31, 2023 and September 30, 2022, the Company had agreements in place to hedge forecasted natural gas purchases of 2.2 million and 3.8 million MMBtus, respectively.

On March 1, 2023, the Company de-designated its natural gas cash flow hedges related to its Ogden, Utah production facility as the Company did not believe these hedges were probable of being highly effective in the second fiscal quarter of 2023. Beginning March 1, 2023, the change in the derivative was and will be recorded in other expense, net in the Consolidated Statements of Operations. Since the transactions are still probable of occurring, previously recognized amounts in AOCL of $0.5 million will remain in AOCL until the underlying forecasted transaction occurs. The Company recognized $0.5 million of expense in other expense, net on the Consolidated Statements of Operations during the three months ended March 31, 2023. Following the de-designation, these natural gas economic hedging instruments will be recorded at fair value through earnings unless re-designated or until settlement. Substantially all other natural gas derivative instruments held by the Company as of March 31, 2023 and September 30, 2022 qualified and were designated as cash flow hedges. As of March 31, 2023, the Company expects to reclassify from AOCL to earnings during the next twelve months $4.9 million of net losses on derivative instruments related to its natural gas hedges. Refer to Note 14 for the estimated fair value of the Company’s natural gas derivative instruments as of March 31, 2023 and September 30, 2022.

The following tables present the fair value of the Company’s derivatives (in millions):

	Asset Derivatives			Liability Derivatives
	Consolidated Balance Sheet Location	March 31, 2023		Consolidated Balance Sheet Location	March 31, 2023
Derivatives designated as hedging instruments:
Commodity contracts	Other current assets	$	0.7	Accrued expenses and other current liabilities	$	5.6
Commodity contracts	Other assets	—		Other noncurrent liabilities	0.6
Total derivatives designated as hedging instruments		0.7			6.2
Derivatives not designated as hedging instruments:
Commodity contracts	Other current assets	—		Accrued expenses and other current liabilities	0.5
Total derivatives not designated as hedging instruments		—			0.5
Total derivatives(a)		$	0.7		$	6.7

(a)The Company has master netting agreements with its commodity hedge counterparties and accordingly has netted in its Consolidated Balance Sheets $0.7 million of its commodity contracts that are in receivable positions against its contracts in payable positions.

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	Asset Derivatives			Liability Derivatives
	Consolidated Balance Sheet Location	September 30, 2022		Consolidated Balance Sheet Location	September 30, 2022
Derivatives designated as hedging instruments:
Commodity contracts	Other current assets	$	2.7	Accrued expenses and other current liabilities	$	3.3
Commodity contracts	Other assets	0.2		Other noncurrent liabilities	0.7
Total derivatives designated as hedging instruments(a)		$	2.9		$	4.0

(a)The Company has master netting agreements with its commodity hedge counterparties and accordingly has netted in its Consolidated Balance Sheets $2.9 million of its commodity contracts that are in receivable positions against its contracts in payable positions.

14.    Fair Value Measurements:

The Company’s financial instruments are measured and reported at their estimated fair values. Fair value is the price that would be received to sell an asset or paid to transfer a liability in an orderly transaction. When available, the Company uses quoted prices in active markets to determine the fair values for its financial instruments (Level 1 inputs) or, absent quoted market prices, observable market-corroborated inputs over the term of the financial instruments (Level 2 inputs). The Company does not have any unobservable inputs that are not corroborated by market inputs (Level 3 inputs).

The Company holds marketable securities associated with its defined contribution and pre-tax savings plans, which are valued based on readily available quoted market prices. The Company utilizes derivative instruments to manage its risk of changes in natural gas prices and foreign exchange rates (see Note 13). The fair values of the natural gas and foreign currency derivative instruments are determined using market data of forward prices for all of the Company’s contracts. 

The estimated fair values for each type of instrument are presented below (in millions):

	March 31, 2023		Level One		Level Two		Level Three
Asset Class:
Mutual fund investments in a non-qualified savings plan(a)	$	2.5	$	2.5	$	—	$	—
Total Assets	$	2.5	$	2.5	$	—	$	—
Liability Class:
Derivatives designated as hedging instruments - natural gas instruments, net	$	(5.5)	$	—	$	(5.5)	$	—
Derivatives not designated as hedging instruments - natural gas instruments, net	(0.5)		—		(0.5)		—
Liabilities related to non-qualified savings plan	(2.5)		(2.5)		—		—
Total Liabilities	$	(8.5)	$	(2.5)	$	(6.0)	$	—

(a)Includes mutual fund investments of approximately 25% in common stock of large-cap U.S. companies, 5% in common stock of small to mid-cap U.S. companies, 10% in international companies, 15% in bond funds, 5% in short-term investments and 40% in blended funds.

	September 30, 2022		Level One		Level Two		Level Three
Asset Class:
Mutual fund investments in a non-qualified savings plan(a)	$	1.8	$	1.8	$	—	$	—
Total Assets	$	1.8	$	1.8	$	—	$	—
Liability Class:
Derivatives – natural gas instruments, net	$	(1.1)	$	—	$	(1.1)	$	—
Liabilities related to non-qualified savings plan	(1.8)		(1.8)		—		—
Total Liabilities	$	(2.9)	$	(1.8)	$	(1.1)	$	—

(a)Includes mutual fund investments of approximately 30% in the common stock of large-cap U.S. companies, 5% in the common stock of small to mid-cap U.S. companies, 10% in the common stock of international companies, 15% in bond funds, 5% in short-term investments and 35% in blended funds.

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Cash and cash equivalents, receivables (net of allowance for doubtful accounts) and accounts payable are carried at cost, which approximates fair value due to their liquid and short-term nature. The Company’s investments related to its nonqualified retirement plan of $2.5 million at March 31, 2023 and $1.8 million at September 30, 2022, are stated at fair value based on quoted market prices. As of March 31, 2023 and September 30, 2022, the estimated fair value of the Company’s fixed-rate 4.875% Senior Notes due July 2024, based on available trading information (Level 2), totaled $237.4 million and $235.9 million, respectively, compared with the aggregate principal amount at maturity of $250.0 million. As of March 31, 2023 and September 30, 2022, the estimated fair value of the Company’s fixed-rate 6.75% Senior Notes due December 2027, based on available trading information (Level 2), totaled $472.5 million and $468.9 million, respectively, compared with the aggregate principal amount at maturity of $500.0 million. The fair value at March 31, 2023 and September 30, 2022 of amounts outstanding under the Company’s term loans and revolving credit facility, based upon available bid information received from the Company’s lender (Level 2), totaled approximately $16.7 million and $158.5 million, respectively, compared with the aggregate principal amount at maturity of $16.9 million and $168.4 million, respectively.

15.    Earnings per Share:

The Company calculates earnings per share using the two-class method. The two-class method requires allocating the Company’s net earnings to both common shares and participating securities. The following table sets forth the computation of basic and diluted earnings per common share (in millions, except for share and per-share data):

	Three Months Ended March 31,				Six Months Ended March 31,
	2023		2022		2023		2022
Numerator:
Net loss from continuing operations	$	(21.6)	$	(29.0)	$	(21.9)	$	(21.1)
Less: net earnings allocated to participating securities(a)	(0.1)		—		(0.2)		(0.1)
Net loss from continuing operations available to common stockholders	(21.7)		(29.0)		(22.1)		(21.2)
Net earnings from discontinued operations available to common stockholders	—		16.9		—		11.4
Net loss available to common stockholders	$	(21.7)	$	(12.1)	$	(22.1)	$	(9.8)
Denominator (in thousands):
Weighted-average common shares outstanding, shares for basic earnings per share	41,110		34,103		40,423		34,081
Weighted-average awards outstanding(b)	—		10		—		19
Shares for diluted earnings per share	41,110		34,113		40,423		34,100
Basic net loss from continuing operations per common share	$	(0.53)	$	(0.85)	$	(0.55)	$	(0.62)
Basic net earnings from discontinued operations per common share	—		0.49		—		0.33
Basic net loss per common share	$	(0.53)	$	(0.36)	$	(0.55)	$	(0.29)
Diluted net loss from continuing operations per common share	$	(0.53)	$	(0.85)	$	(0.55)	$	(0.62)
Diluted net earnings from discontinued operations per common share	—		0.49		—		0.33
Diluted net loss per common share	$	(0.53)	$	(0.36)	$	(0.55)	$	(0.29)

(a)Weighted participating securities include RSUs and PSUs that receive non-forfeitable dividends and consist of 439,000 and 477,000 weighted participating securities for the three and six months ended March 31, 2023, respectively and 407,000 and 419,000 weighted participating securities for the three and six months ended March 31, 2022, respectively.

(b)For the calculation of diluted net earnings (loss) per share, the Company uses the more dilutive of either the treasury stock method or the two-class method to determine the weighted-average number of outstanding common shares. In addition, the Company had 1,193,000 and 1,275,000 weighted-average equity awards outstanding for the three and six months ended March 31, 2023, respectively, and 1,125,000 and 1,115,000 weighted-average equity awards outstanding for the three and six months ended March 31, 2022, respectively that were anti-dilutive.

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16.    Related Party Transactions:

As discussed in Note 12, on October 18, 2022, KII, through its KM&T subsidiary, purchased common stock representing an ownership interest of approximately 17% of the outstanding common stock of the Company. As part of the Stock Purchase Agreement, KM&T appointed two members to the Company’s board of directors, effective November 13, 2022. In addition, the companies continue to explore value creation opportunities.

During the three and six months ended March 31, 2023, the Company recorded SOP sales of approximately $0.9 million and $1.8 million, respectively, to certain subsidiaries of KII, compared to $0.7 million and $1.4 million during the three and six months ended March 31, 2022, respectively. As of March 31, 2023 and September 30, 2022, the Company had approximately $0.5 million and $0.4 million, respectively, of Receivables from related parties on its Consolidated Balance Sheets. Additionally, a subsidiary of KII has recently provided engineering services for the Company’s lithium development project for which it capitalized approximately $2.7 million into Property, Plant and Equipment, net, as of March 31, 2023. There were no amounts payable outstanding as of March 31, 2023.

On March 20, 2023, the Company paid a cash dividend to its stockholders of record at the close of business on March 10, 2023 in the amount of $0.15 per share, or $6.3 million in the aggregate. KM&T received approximately $1.0 million in respect to its common shares.

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Item 2.    Management’s Discussion and Analysis of Financial Condition and Results of Operations

All statements, other than statements of historical fact, contained in this Quarterly Report on Form 10-Q constitute “forward-looking statements” within the meaning of the Private Securities Litigation Reform Act of 1995.

Forward-looking statements relate to future events or our future financial performance, and involve known and unknown risks, uncertainties, and other factors that may cause our actual results, levels of activity, performance or achievements to be materially different from future results, levels of activity, performance or achievements expressed or implied by these forward-looking statements. Factors that could cause actual results to differ materially from those expressed or implied by the forward-looking statements include, but are not limited to, the following: our mining and industrial operations; geological conditions; dependency on a limited number of key production and distribution facilities and critical equipment; weather conditions; uncertainties in estimating our economically recoverable reserves and resources; the inability to fund necessary capital expenditures or successfully complete capital projects; strikes, other forms of work stoppage or slowdown or other union activities; supply constraints or price increases for energy and raw materials used in our production processes; our indebtedness and inability to pay our indebtedness; restrictions in our debt agreements that may limit our ability to operate our business or require accelerated debt payments; tax liabilities; the inability of our customers to access credit or a default by our customers of trade credit extended by us; our payment of any dividends; financial assurance requirements; the impact of competition on the sales of our products; inflation risks; increasing costs or a lack of availability of transportation services; the seasonal demand for our products; risks associated with our international operations and sales, including changes in currency exchange rates; the impact of anticipated changes in potash product prices and customer application rates; conditions in the sectors where we sell products and supply and demand imbalances for competing products; our rights and governmental authorizations to mine and operate our properties; risks related to unanticipated litigation or investigations or pending litigation or investigations or other contingencies; compliance with environmental, health and safety laws and regulations; environmental liabilities; compliance with foreign and United States (“U.S.”) laws and regulations related to import and export requirements and anti-corruption laws; changes in laws, industry standards and regulatory requirements; product liability claims and product recalls; misappropriation or infringement claims relating to intellectual property; inability to obtain required product registrations or increased regulatory requirements; our ability to successfully implement our strategies; plans to develop our lithium resource, including market entry and market changes from potential competing technologies; the useful life of our mine properties; our expectation of extending the Goderich mineral lease; conversion of mineral resources into mineral reserves; risks related to labor shortages and the loss of key personnel; a compromise of our computer systems, information technology or operations technology or the inability to protect confidential or proprietary data; climate change and related laws and regulations; our continued ability to access ambient lake brine in the Great Salt Lake; our ability to expand our business through acquisitions and investments, realize anticipated benefits from acquisitions and investments and integrate acquired businesses; outbreaks of contagious disease or similar public health threats; domestic and international general business and economic conditions; and other risks referenced from time to time in this report and our other filings with the Securities and Exchange Commission (the “SEC”), including Part I, Item 1A, “Risk Factors” of our Annual Report on Form 10-K for the annual period ended September 30, 2022.

In some cases, you can identify forward-looking statements by terminology such as “may,” “might,” “will,” “should,” “could,” “expects,” “intends,” “plans,” “anticipates,” “believes,” “estimates,” “predicts,” “potential,” “continue,” the negative of these terms or other comparable terminology. Forward-looking statements include without limitation statements about our outlook, including expected sales volumes and costs; existing or potential capital expenditures; capital projects and investments; the industry and our competition; projected sources of cash flow; potential legal liability; proposed or recently enacted legislation and regulatory action; the seasonal distribution of working capital requirements; our reinvestment of foreign earnings outside the U.S.; payment of future dividends and ability to reinvest in our business; our ability to optimize cash accessibility, minimize tax expense and meet debt service requirements; future tax payments, tax refunds and valuation allowances; leverage ratios; realization of potential savings from our restructuring activities; outcomes of matters with taxing authorities; the effects of currency fluctuations and inflation, including our ability to recover inflation-based cost increases; the seasonality of our business; the effects of climate change; and the impact of the global economy, COVID-19 pandemic and the war in Ukraine on us. These forward-looking statements are only predictions. Actual events or results may differ materially.

Although we believe that the expectations reflected in the forward-looking statements are reasonable, we cannot guarantee future results, levels of activity, performance or achievements. We undertake no duty to update any of the forward-looking statements after the date hereof or to reflect the occurrence of unanticipated events.

Unless the context requires otherwise, references to the “Company,” “Compass Minerals,” “our,” “us” and “we” refer to Compass Minerals International, Inc. (“CMI,” the parent holding company) and its consolidated subsidiaries. Except where otherwise noted, references to North America include only the continental U.S. and Canada, and references to the United

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Kingdom (“U.K.”) include only England, Scotland and Wales. Except for lithium quantities which are stated in metric tons or where otherwise noted, all references to tons refer to “short tons” and all amounts are in U.S. dollars. One short ton equals 2,000 pounds and one metric ton equals 2,204.6 pounds. Compass Minerals and Protassium+ and combinations thereof, are trademarks of CMI or its subsidiaries in the U.S. and other countries. 

Discontinued Operations

On March 16, 2021, the Board of the Directors approved a plan to sell our South America chemicals and specialty plant nutrition businesses, our investment in Fermavi Eletroquímica Ltda. (“Fermavi”) and our North America micronutrient product business (collectively, the “Specialty Businesses”) with the goal of reducing our leverage and enabling increased focus on optimizing our core businesses.

As described further in Item 1, Note 2 of our Consolidated Financial Statements, we sold our South America specialty plant nutrition business, a component of our North America micronutrient business, our Fermavi investment and our South America chemicals business, respectively.

We believe these dispositions were conducted through a single disposal plan representing a strategic shift that has had a material effect on our operations and financial results. Consequently, the Specialty Businesses qualify for presentation as discontinued operations in accordance with U.S. generally accepted accounting principles (“U.S. GAAP”). The dispositions were completed during fiscal 2022; accordingly, the results of operations of the Specialty Businesses are presented as discontinued operations in the Consolidated Statements of Operations for the three and six months ended March 31, 2022.

Unless otherwise indicated, the information and amounts provided in this “Management’s Discussion and Analysis of Financial Condition and Results of Operations” pertain to continuing operations.

Critical Accounting Estimates

Preparation of our consolidated financial statements in accordance with U.S. GAAP requires management to make estimates and assumptions that affect the reported amounts of assets, liabilities, revenues and expenses. Management believes the most complex and sensitive judgments result primarily from the need to make estimates about matters that are inherently uncertain. Part II, Item 7, “Management’s Discussion and Analysis of Financial Condition and Results of Operations” and Part II, Item 8, Note 2 to the Consolidated Financial Statements included in our Annual Report on Form 10-K for the annual period ended September 30, 2022, describe the significant accounting estimates and policies used in preparation of our consolidated financial statements. For a further description of our critical accounting policies, see Item 1, Note 1 of our Consolidated Financial Statements included in this Quarterly Report on Form 10-Q. Actual results in these areas could differ from management’s estimates.

Company Overview

Compass Minerals is a leading producer of essential minerals, including salt, sulfate of potash (“SOP”) specialty fertilizer and magnesium chloride. As of March 31, 2023, we operated 12 production and packaging facilities, including:

•The largest rock salt mine in the world in Goderich, Ontario, Canada;

•The largest dedicated rock salt mine in the U.K. in Winsford, Cheshire;

•A solar evaporation facility located near Ogden, Utah, which is both the largest sulfate of potash specialty fertilizer production site and the largest solar salt production site in the Western Hemisphere; and

•Several mechanical evaporation facilities producing consumer and industrial salt.

Our Salt segment provides highway deicing salt to customers in North America and the U.K. as well as consumer deicing and water conditioning products, ingredients used in consumer and commercial food preparation, and other salt-based products for consumer, industrial, chemical and agricultural applications in North America. In the U.K., we operate a records management business utilizing excavated areas of our Winsford salt mine with one other location in London, England.

Our Plant Nutrition segment produces and markets SOP products in various grades worldwide to distributors and retailers of crop inputs, as well as growers and for industrial uses. We market our SOP under the trade name Protassium+. 

Additionally, we are pursuing development of a sustainable lithium brine resource near Ogden, UT to support the North American battery market and we are a minority owner of Fortress North America, LLC (“Fortress”), a next-generation fire retardant company. On May 5, 2023, we acquired the remaining 55% interest in Fortress as described in Item1, Note 7 of our

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Consolidated Financial Statements. Prior to the acquisition, Fortress entered into an agreement with the U.S. Forest Service to supply product and provide associated services for the 2023 fire season.

Consolidated Results of Continuing Operations

The following is a summary of our consolidated results of continuing operations for the three and six months ended March 31, 2023 and 2022, respectively. The following discussion should be read in conjunction with the information contained in our consolidated financial statements and the notes thereto included in this Quarterly Report on Form 10-Q.

THREE AND SIX MONTHS ENDED MARCH 31

* Refer to “—Reconciliation of Net Loss from Continuing Operations to EBITDA and Adjusted EBITDA” for a reconciliation to the most directly comparable U.S. GAAP financial measure and the reasons we use this non-GAAP measure.

Commentary: Three Months Ended March 31, 2023 Compared to Three Months Ended March 31, 2022

•Total sales decreased 8%, or $37.4 million, due to lower Salt and Plant Nutrition segment sales. The decrease in sales for both Salt and Plant Nutrition reflected lower sales volumes, partially offset by higher average sales prices.

•Operating earnings increased 140%, or $27.9 million, to $47.9 million, reflecting higher Salt operating earnings which were partially offset by lower Plant Nutrition operating earnings. Salt operating earnings increased due primarily to higher average sales prices, which were partially offset by higher SG&A costs, including restructuring costs. Plant Nutrition operating earnings decreased due primarily to lower sales volumes as the unusually wet weather in our California market reduced demand, higher per-unit product costs and higher per-unit distribution costs reflective of the higher proportion of sales to more distant markets, partially offset by higher average sales prices. Corporate and Other segment operating loss declined from the prior year quarter primarily reflecting the absence of legal and accrued settlement costs associated with the SEC investigation partially offset by severance costs related to the restructuring activities recorded in the second quarter of 2023.

•Earnings before interest, taxes, depreciation and amortization (“EBITDA”)* adjusted for items management believes are not indicative of our ongoing operating performance (“Adjusted EBITDA”)* increased 19%, or $12.6 million.

•Diluted net loss per share improved by $0.32 to $0.53 per share.

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Commentary: Six Months Ended March 31, 2023 Compared to Six Months Ended March 31, 2022

•Total sales decreased 2%, or $16.5 million, due to a decrease in our Plant Nutrition segment sales, which was partially offset by slightly higher Salt segment sales. The decline in Plant Nutrition sales was primarily driven by lower sales volumes, partially offset by higher average sales prices. The increase in Salt sales primarily reflects higher sales prices.

•Operating earnings increased 88%, or $35.4 million, due to an increase in the Salt segment driven primarily by higher average sales prices, which were partially offset by higher per-unit product and distribution costs. The Salt increase in operating earnings was partially offset by a decrease in our Plant Nutrition segment due to lower sales volumes, partially offset by higher average sales price. Corporate and Other segment SG&A expenses decreased primarily reflecting the absence of legal and accrued settlement costs associated with the SEC investigation and lower consulting costs, partially offset by costs related to current year restructuring activities.

•Adjusted EBITDA increased 13%, or $16.0 million.

•Diluted net loss per common share of $0.55 improved from diluted net loss of $0.62 per common share.

THREE AND SIX MONTHS ENDED MARCH 31

Commentary: Three Months Ended March 31, 2023 Compared to Three Months Ended March 31, 2022

Gross Profit: Increased 32%, or $20.6 million; Gross Margin increased 7 percentage points to 21%

•Salt segment gross profit increased $25.4 million primarily due to higher average sales prices and lower per-unit logistics costs, which were partially offset by lower sales volumes (see Salt operating results).

•The gross profit of the Plant Nutrition segment decreased $4.8 million due to higher per-unit product costs, lower sales volumes and higher per-unit logistics costs, which were partially offset by higher average sales prices (see Plant Nutrition operating results).

Commentary: Six Months Ended March 31, 2023 Compared to Six Months Ended March 31, 2022

Gross Profit: Increased 25%, or $30.7 million; Gross Margin increased 4 percentage points to 20%

•Salt segment gross profit increased $34.5 million primarily due to higher average sales prices, which were partially offset by higher per-unit product and distribution costs (see Salt operating results).

•The gross profit of the Plant Nutrition segment decreased $3.8 million due to higher per-unit product costs, lower sales volumes and higher per-unit distribution costs, which were partially offset by higher average sales prices (see Plant Nutrition operating results).

OTHER EXPENSES AND INCOME

Commentary: Three Months Ended March 31, 2023 Compared to Three Months Ended March 31, 2022

SG&A: Decreased $7.3 million; decreased 0.8 percentage points as a percentage of sales from 9.9% to 9.1%

•The decrease in SG&A expense was primarily due to corporate lower legal expenses due to higher costs in the prior period related to the recently completed SEC investigation, partially offset by costs related to our recently announced restructuring activities.

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Interest Income: Increased to $1.9 million

•The increase in interest income is primarily due to a higher cash balance during the current period resulting from proceeds received from the private placement of our common stock.

Interest Expense: Increased $0.3 million to $14.2 million

•Interest expense increased $0.3 million as higher interest rates in the current period were mostly offset by lower debt levels.

(Gain) Loss on Foreign Exchange: Changed $3.2 million from a loss of $3.0 million to a gain of $0.2 million

•We realized foreign exchange gains of $0.2 million in the second quarter of fiscal 2023 compared to losses of $3.0 million in the same quarter of the prior fiscal year, primarily reflecting changes in translating our intercompany loans from Canadian dollars to U.S. dollars.

Net Loss in Equity Investees: Decreased $0.3 million to $1.4 million

•We realized a net loss in equity investees of $1.4 million for the three months ended March 31, 2023 compared to $1.7 million in the prior-year period reflecting our share of losses related to our equity investments as these development stage businesses position themselves for commercialization.

Other Expense: Increased to an expense of $0.9 million

•The increase is due primarily to the mark to market of economic hedges that were de-designated from hedge accounting during the quarter ended March 31, 2023.

Income Tax (Benefit) Expense: Increased $24.7 million from $30.4 million to $55.1 million

•Income tax expense increased primarily due to higher pretax book income in the three months ended March 31, 2023 as compared to the three months ended March 31, 2022 partially offset by lower valuation allowance expense recorded in the three months ended March 31, 2023 as compared to the three months ended March 31, 2022.

•Our effective tax rate of 164% for the three months ended March 31, 2023 is primarily driven by the income mix by country with income recognized in foreign jurisdictions partially offset by losses recognized in the U.S., for which a valuation allowance has been recorded against the U.S. tax benefit carryforward. Additionally, the interest related to Canadian provincial tax authority assessments has a greater impact on the effective tax rate when pretax book income decreases. See Item 1, Note 8 to the Consolidated Financial Statements.

•Our income tax provision for the three months ended March 31, 2023 and 2022 differs from the U.S. statutory rate primarily due to U.S. statutory depletion, state income taxes, base erosion and anti-abuse tax, nondeductible executive compensation, foreign income, mining and withholding taxes and valuation allowance expense. Additionally, the income tax provision for the three months ended March 31, 2022 included interest expense recognition differences for tax and financial reporting purposes and nondeductible contingent loss accrual.

Net Earnings from Discontinued Operations: $16.9 million in the second quarter of fiscal 2022

•The net earnings from discontinued operations for the prior period includes the results from our chemicals business in South America net of an impairment loss recognized prior to the April 20, 2022 sale date.

•The prior period net earnings of the South America chemicals business included a $20.4 million foreign currency exchange gain and an impairment loss of $16.3 million to record the net assets of the South America chemical business at fair value less cost to sell which reflected the foreign currency translation adjustment. Refer to Item 1, Note 2 to the Consolidated Financial Statements for additional details.

Commentary: Six Months Ended March 31, 2023 Compared to Six Months Ended March 31, 2022

SG&A: Decreased $4.7 million; Decreased 0.4 percentage points as a percentage of sales from 10.8% to 10.4%

•The decrease in SG&A expense was primarily due to lower corporate legal expenses due to higher costs in the prior period related to the recently completed SEC investigation and executive transition costs, partially offset by higher stock-based compensation and costs related to restructuring activities in the current period.

Interest Income: Increased $2.7 million from $0.3 million to $3.0 million

•The increase in interest income is primarily due to a higher cash balance during the current period resulting from proceeds received from the private placement of our common stock.

Interest Expense: Increased $0.3 million to $28.1 million

•Interest expense increased as lower debt levels in the current period were offset by higher interest rates.

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Loss on Foreign Exchange: Decreased $0.3 million from a loss of $2.6 million to a loss of $2.3 million

•We realized foreign exchange losses of $2.3 million and $2.6 million in the first six months of 2023 and 2022, respectively, due primarily to changes in translating our intercompany loans from Canadian dollars to U.S. dollars.

Net Loss in Equity Investees: Increased $0.2 million to $2.3 million

•We realized a net loss in equity investees of $2.3 million for the six months ended March 31, 2023 compared to $2.1 million in the prior-year period reflecting our share of losses related to our equity investments as these development stage businesses position themselves for commercialization.

Other Expense: Increased $0.9 million from expense of $0.1 million to an expense of $1.0 million

•The increase is due primarily to the mark to market of economic hedges that were de-designated from hedge accounting during the quarter ended March 31, 2023.

Income Tax Expense: Increased $37.8 million from $29.2 million to $67.0 million

•Income tax expense increased primarily due to higher pretax book income in the six months ended March 31, 2023 as compared to the six months ended March 31, 2022 partially offset by lower valuation allowance expense recorded in the six months ended March 31, 2023 as compared to the six months ended March 31, 2022.

•Our effective tax rate of 149% for the six months ended March 31, 2023 is primarily driven by the income mix by country with income recognized in foreign jurisdictions partially offset by losses recognized in the U.S., for which a valuation allowance has been recorded against the U.S. tax benefit carryforward. Additionally, the interest related to Canadian provincial tax authority assessments has a greater impact on the effective tax rate when pretax book income decreases. See Item 1, Note 8 to the Consolidated Financial Statements.

•Our income tax provision for the six months ended March 31, 2023 and 2022 differs from the U.S. statutory rate primarily due to U.S. statutory depletion, state income taxes, base erosion and anti-abuse tax, nondeductible executive compensation, foreign income, mining and withholding taxes and valuation allowance expense. Additionally, the income tax provision for the six months ended March 31, 2022 included interest expense recognition differences for tax and financial reporting purposes and nondeductible contingent loss accrual.

Net Earnings from Discontinued Operations: $11.4 million in the first six months of fiscal 2022

•The net earnings from our discontinued operations for the six months ended March 31, 2022 includes the results of the South America Chemicals business prior to the April 20, 2022 sale date.

•The prior period results of the South America chemicals business includes a foreign currency exchange rate gain of $17.3 million offset by an impairment loss of $24.7 million to record the net assets of the South America business at its fair value less cost to sell. Refer to Item 1, Note 2 to the Consolidated Financial Statements for additional details.

Operating Segment Performance

The following financial results represent consolidated financial information with respect to the operations of our Salt and Plant Nutrition segments. The results of operations of the records management business and other incidental revenues, include sales of $2.9 million for the each of three months ended March 31, 2023 and 2022, and $5.6 million and $5.9 million for the six months ended March 31, 2023 and 2022, respectively. These revenues are not material to our consolidated financial results and are not included in the following operating segment financial data.

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Salt

THREE AND SIX MONTHS ENDED MARCH 31

	QTD 2023		QTD 2022		YTD 2023		YTD 2022
Salt Sales (in millions)	$	360.5	$	391.3	$	668.6	$	665.2
Salt Operating Earnings (in millions)	$	73.1	$	49.3	$	120.2	$	88.7
Salt Sales Volumes (thousands of tons)
Highway deicing	3,915		4,815		6,816		7,622
Consumer and industrial	488		516		1,108		1,149
Total tons sold	4,403		5,331		7,924		8,771
Average Salt Sales Price (per ton)
Highway deicing	$	69.90	$	62.31	$	68.07	$	60.85
Consumer and industrial	$	177.77	$	176.86	$	184.63	$	175.28
Combined	$	81.87	$	73.39	$	84.37	$	75.84

Commentary: Three Months Ended March 31, 2023 Compared to Three Months Ended March 31, 2022

•Salt sales decreased 8%, or $30.8 million, primarily due to lower sales volumes, partially offset by higher average sales prices.

•Salt sales volumes decreased 17%, or 928,000 tons, reducing sales by approximately $61.0 million. Highway deicing sales volumes decreased 19%, reflecting the lower sales commitment volumes in North America which were partially offset by higher U.K. sales volumes in the second quarter of 2023. Consumer and industrial sales volumes decreased 5% due to lower deicing volumes.

•Average sales prices increased 12% partially offsetting the volume decline by approximately $30.2 million with increases in both highway and consumer and industrial average sales prices.

•Highway deicing average sales price increased 12% across all product categories as we have sought to improve our sales commitment portfolio to restore profitability and offset the impact of inflation on costs.

•Salt operating earnings increased 48%, or $23.8 million, primarily due to higher average sales prices and lower logistics costs in our C&I business, which were partially offset by higher SG&A costs. We incurred restructuring costs related to our cost savings initiatives of approximately $1.0 million during the period related to the Salt segment which contributed to the decline in Salt segment operating earnings.

Commentary: Six Months Ended March 31, 2023 Compared to Six Months Ended March 31, 2022

•Salt sales increased 1%, or $3.4 million, primarily due to higher Salt average sales prices, which were mostly offset by lower sales volumes for both highway and consumer and industrial products.

•Average sales prices increased 11% and contributed $59.6 million to the increase in Salt sales due to increases in both highway and consumer and industrial average sales prices.

•Highway deicing average sales prices increased 12% due to higher North American highway deicing contract prices for the 2023 winter season. Consumer and industrial average sales prices increased 5% primarily due to higher sales prices primarily in response to the recent inflationary environment.

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•Salt sales volumes decreased 10% reducing sales by approximately $56.2 million. Highway deicing sales volumes decreased 11% primarily as a result of a decrease in North American sales commitments. Consumer and industrial sales volumes decreased 4% due to a decrease in deicing sales volumes.

•Salt operating earnings increased 36%, or $31.5 million, due primarily to higher average sales prices for both highway and consumer and industrial products, which were partially offset by higher per-unit product and logistics costs and restructuring costs recognized in the current period. Lower sales volumes compared to the prior period partially offset the increase in operating earnings.

Plant Nutrition

THREE AND SIX MONTHS ENDED MARCH 31

	QTD 2023		QTD 2022		YTD 2023		YTD 2022
Plant Nutrition Sales (in millions)	$	47.7	$	54.3	$	89.3	$	108.9
Plant Nutrition Operating (Loss) Earnings (in millions)	$	(0.7)	$	4.4	$	10.3	$	13.9
Plant Nutrition Sales Volumes (thousands of tons)	60		74		105		157
Plant Nutrition Average Sales Price (per ton)	$	796	$	736	$	851	$	696

Commentary: Three Months Ended March 31, 2023 Compared to Three Months Ended March 31, 2022

•Plant Nutrition sales decreased 12%, or $6.6 million due to lower sales volumes, which were partially offset by higher average sales prices.

•Plant Nutrition sales volumes were lower year over year due to lower demand due to a combination of flooding conditions in California and uncertainty about future fertilizer prices causing users to cancel or delay purchases. The decline in sales volumes decreased sales by approximately $10.3 million.

•Plant Nutrition average sales prices increased 8%, which contributed approximately $3.7 million to partially offset the volume decline. Average sales prices increased from the prior period due to global supply and demand dynamics for fertilizer products which resulted in steadily increasing prices throughout fiscal 2022, which have subsequently declined from the peak.

•Plant Nutrition operating earnings decreased $5.1 million to an operating loss of $0.7 million primarily due to higher per-unit product costs driven by lower production volumes at our Ogden facility as well as higher energy, other input costs and costs of approximately $1.6 million related to a small fire at the Ogden facility, and proportionately fewer sales to more profitable regions, which were partially offset by higher average sales prices.

Commentary: Six Months Ended March 31, 2023 Compared to Six Months Ended March 31, 2022

•Plant Nutrition sales decreased 18%, or $19.6 million, from the prior year as lower sales volumes were partially offset by higher average sales prices.

•Plant Nutrition sales volumes decreased 33%, or 52,000 tons, which resulted in a $35.9 million decrease in sales due to a combination of weather conditions in select key markets, including California, and uncertainty about future fertilizer prices causing customers to cancel or delay purchases.

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•Plant Nutrition average sales prices increased 22%, which partially offset the decrease in sales volume by $16.3 million. Average sales prices increased from the prior period due to the strong worldwide economic climate for fertilizer products which resulted in steadily increasing sales prices throughout fiscal 2022, although prices have recently declined from the peak.

•Plant Nutrition operating earnings decreased $3.6 million to $10.3 million primarily reflecting higher per-unit product costs primarily due to lower production volumes at our Ogden production facility and higher energy and other input costs and proportionately fewer sales to more profitable regions, which were partially offset by significantly higher average sales prices.

Outlook

•With the bulk of the winter season over, Salt segment sales volumes for the fiscal year are expected to range from 11.35 million to 12.2 million tons, with EBITDA expected to range from $215 million to $255 million.

•Plant Nutrition segment product demand was adversely impacted during the first fiscal quarter by drought conditions in California, our largest market for SOP, followed by significant rainfall and flooding in California that impacted fertilizer application rates. Global pricing dynamics for SOP and similar products have shown signs of softening year to date. During the second fiscal quarter our Ogden facility experienced a temporary increase in natural gas costs due to temporary regional pipeline supply and demand dynamics. Plant Nutrition segment sales volumes and EBITDA are expected to range from 205,000 to 270,000 tons and $30 million to $60 million, respectively, in fiscal year 2023.

•Fiscal year 2023 capital expenditures are expected to range from a total of $150 million to $175 million. This amount includes $60 million to $75 million in connection with advancing phase-one of our lithium development.

•In April, we initiated a restructuring plan to reduce ongoing costs and further streamline the organization. The first phase of this initiative resulted in a charge of $3.3 million in the quarter ended March 31, 2023 with an additional $0.7 million anticipated in the quarter ended June 30, 2023. We continue to actively evaluate cost saving opportunities at our production and packaging facilities that could result in additional cost reductions. Accordingly, we may incur additional charges in fiscal 2023 as a result of these activities. For full-year fiscal 2024, we believe these actions, along with the elimination of certain consulting and other overhead costs after fiscal 2023, will benefit our operating expenses and adjusted EBITDA in the range of $17 to $18 million per year.

•On May 5, 2023, we completed the acquisition of the remaining 55% of Fortress for upfront consideration of approximately $26 million in cash, contingent consideration valued at approximately $28 million and an earn-out of $0.30 per gallon on Fortress product sold over a 10-year timeframe. Prior to the acquisition, Fortress entered into an agreement with the U.S. Forest Service to supply product and provide associated services for the 2023 fire season. Fortress is expected to generate between $20 million and $25 million of revenue and operating profit with EBITDA in the low double digit millions of dollars in fiscal 2023.

Liquidity and Capital Resources

Historically, our cash flows from operating activities have generally been adequate to fund our basic operating requirements, ongoing debt service and sustaining investment in our property, plant and equipment. We have also used cash generated from operations to fund capital expenditures, pay dividends, fund smaller acquisitions and repay our debt. To a certain extent, our ability to meet our short- and long-term liquidity and capital needs is subject to general economic, financial, competitive and weather conditions, effects of climate change, geological variations in our mine deposits and other factors that are beyond our control. Historically, our working capital requirements have been the highest in the first fiscal quarter (ending December 31) and lowest in the third fiscal quarter (ending June 30). When needed, we may fund short-term working capital requirements by accessing our $300 million revolving credit facility and our $100 million revolving AR Securitization Facility.

We have been able to manage our cash flows generated and used across Compass Minerals to permanently reinvest earnings in our foreign jurisdictions or efficiently repatriate those funds to the U.S. As of March 31, 2023, we had $40.0 million of cash and cash equivalents that was either held directly or indirectly by foreign subsidiaries. As a result of U.S. tax reform, we revised our permanently reinvested assertion, expecting to repatriate approximately $150 million of unremitted foreign earnings from Canada. In fiscal 2022, we revised our permanently reinvested assertion, expecting to repatriate an additional approximately $10 million of unremitted foreign earnings from our U.K. operations and in the second quarter of fiscal 2023 we revised it again expecting to repatriate an additional approximately $6 million of unremitted foreign earnings from our U.K. operations. During the first quarter of fiscal 2023, $89.2 million was repatriated from Canada. Net income tax expense of $3.8 million has been recorded for foreign withholding tax, state income tax and foreign exchange losses on these changes in assertion as of March 31, 2023, consisting of a tax benefit of $0.7 million recorded in the first six months of fiscal year 2023, a $0.2 million tax benefit recorded in fiscal 2022 and tax expense of $4.7 million recorded in years prior to fiscal 2022. Due to our ability to generate adequate levels of U.S. cash flow on an annual basis, it is our current intention to continue to reinvest the remaining

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undistributed earnings of our foreign subsidiaries indefinitely. We review our tax circumstances on a regular basis with the intent of optimizing cash accessibility and minimizing tax expense.

In addition, the amount of permanently reinvested earnings is influenced by, among other things, the profits generated by our foreign subsidiaries and the amount of investment in those same subsidiaries. The profits generated by our U.S. and foreign subsidiaries are impacted by the transfer price charged on the transfer of our products between them. Canadian provincial taxing authorities continue to challenge our transfer prices of certain items. The final resolution of these challenges may not occur for several years. We currently expect the outcome of these matters will not have a material impact on our results of operations. However, it is possible the resolution could materially impact the amount of earnings attributable to our foreign subsidiaries, which could impact the amount of permanently reinvested foreign earnings. See Item 1, Note 8 of our Consolidated Financial Statements for a discussion regarding our Canadian tax reassessments.

Management assesses the available positive and negative evidence to estimate whether sufficient future taxable income will be generated to permit use of the existing deferred tax assets. A significant piece of objective negative evidence evaluated was the cumulative loss incurred in the U.S. over the three-year period ended March 31, 2023. Such objective evidence limits the ability to consider other subjective evidence, such as our projections for future income. On the basis of this evaluation, during the six months ended March 31, 2023, an additional valuation allowance of $15.8 million has been recorded to recognize only the portion of the U.S. deferred tax assets that are more likely than not to be realized. The amount of the deferred tax assets considered realizable, however, could be adjusted if estimates of future taxable income during the carryforward period are increased or reduced or if objective negative evidence in the form of cumulative losses is no longer present and additional weight is given to subjective evidence such as our projections for income.

Cash and cash equivalents as of March 31, 2023 was $249.7 million. We generated $143.9 million of operating cash flows during the six months ended March 31, 2023, including a decrease in our working capital. During the six-month period ended March 31, 2023, we used cash on hand, cash flows from operations and cash proceeds from the private placement to fund capital expenditures of $43.7 million, pay down net debt of $123.1 million and pay dividends on our common stock of $12.6 million. Cash and cash equivalents of $249.7 million increased $203.6 million from September 30, 2022. Cash flows from operating activities totaled $143.9 million during the six months ended March 31, 2023, including net loss from continuing operations of $21.9 million, depreciation, depletion and amortization of $48.4 million, and a net working capital decrease of $99.4 million driven primarily by the seasonality of our Salt business and an increase in income tax payable due to the high effective tax rate driven by a U.S. valuation allowance. Our working capital decrease primarily reflects depleted inventory at the conclusion of the winter season which begins in the first quarter (ending December 31) of each fiscal year.

Indebtedness

As of March 31, 2023, we had $832.8 million of outstanding indebtedness, consisting of $250.0 million outstanding under our 4.875% Senior Notes due 2024, $500.0 million outstanding under our 6.75% Senior Notes due 2027, $16.9 million of borrowings outstanding under our senior secured credit facilities under the Credit Agreement, consisting entirely of term loans, and $65.9 million of outstanding loans under the accounts receivable financing facility (see Item 1, Note 9 of our Consolidated Financial Statements for more detail regarding our debt). Outstanding letters of credit totaling $13.6 million as of March 31, 2023 reduced available borrowing capacity under our revolving credit facility to $286.4 million. During the quarter ended December 31, 2022, we paid off the outstanding revolving credit facility balance utilizing proceeds from a private placement of common stock. Refer to Item 1, Note 12 of our Consolidated Financial Statements for additional details of the private placement transaction.

In November 2022, we entered into the third amendment to the Credit Agreement, principally to affect a transition from the London Inter-Bank Offered Rate to the Secured Overnight Financing Rate pricing benchmark provisions.

In January 2023, certain of our U.S. subsidiaries entered into the second amendment to the AR Securitization Facility with PNC Bank, which temporarily eases the restrictions of certain covenants contained in the agreement through March 2023. The amendment made certain adjustments to the financial tests including: (i) the default ratio and (ii) the delinquency ratio to make compliance with such tests more likely.

On May 5, 2023, we entered into an agreement to amend and restate our credit agreement entered into on November 26, 2019 (as in effect prior to such restatement, the “Existing Credit Agreement”) with a new $575 million senior secured credit agreement due May 5, 2028 (as amended, the “2023 Credit Agreement”), comprised of a $375 million revolving credit facility and $200 million term loan. The term loan is payable in quarterly installments of interest and principal beginning September 30, 2023. The 2023 Credit Agreement increases the Applicable Margins by 0.0025 basis points over those defined in the Existing Credit Agreement and adds an additional level at a consolidated total leverage ratio of greater than 4 to 1. Consolidated total net

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debt includes the aggregate principal amount of total debt, net of unrestricted cash which was increased from $50.0 million to $75 million in the 2023 Credit Agreement. Proceeds from the 2023 Credit Agreement will be used to redeem our $250 million 4.875% Senior Notes on May 10, 2023 and pay off the Existing Credit Agreement term loan balance of $16.9 million. Refer to Item 1, Note 9 of our Consolidated Financial Statements for additional details.

In the future, including during fiscal 2023, we may borrow amounts under the revolving credit facility or enter into additional financing to fund our working capital requirements, potential acquisitions and capital expenditures and for other general corporate purposes.

Our ability to make scheduled interest and principal payments on our indebtedness, to refinance our indebtedness, to fund planned capital expenditures and to fund acquisitions will depend on our ability to generate cash in the future. This, to a certain extent, is subject to general economic, financial, competitive, legislative, climate-related, regulatory and other factors that are beyond our control. Based on our current level of operations, we believe that cash flow from operations and available cash, together with available borrowings under our revolving credit facility, will be adequate to meet our liquidity needs over the next 12 months.

Our debt service obligations could, under certain circumstances, materially affect our financial condition and prevent us from fulfilling our debt obligations. As a holding company, CMI’s investments in its operating subsidiaries constitute substantially all of its assets. Consequently, our subsidiaries conduct substantially all of our consolidated operating activities and own substantially all of our operating assets. The principal source of the cash needed to pay our obligations is the cash generated from our subsidiaries’ operations and their borrowings. Furthermore, we must remain in compliance with the terms of the Credit Agreement governing our credit facilities, including the consolidated total net leverage ratio and interest coverage ratio, in order to pay dividends to our stockholders. We must also comply with the terms of our indenture governing our 4.875% Senior Notes due July 2024 and our 6.75% Senior Notes due December 2027, which limit the amount of dividends we can pay to our stockholders.

Pursuant to the terms of the second amendment to our Credit Agreement, the maximum allowed consolidated total net leverage ratio (as defined and calculated under the terms of the Credit Agreement and discussed further below) was 5.0x for the quarter ended March 31, 2022, which steps down to 4.75x in the quarter ending March 31, 2024, and to 4.5x for the fiscal quarter ended June 30, 2024 and thereafter. The consolidated total net leverage ratio represents the ratio of (a) consolidated total net debt to (b) consolidated adjusted EBITDA. Consolidated total net debt includes the aggregate principal amount of total debt, net of unrestricted cash not to exceed $50.0 million. Under the 2023 Credit Agreement, finalized May 5, 2023, all existing debt covenants remain unchanged except the amount of unrestricted cash allowed to reduce the aggregate principal amount of total debt in the calculation of the consolidated total net leverage ratio was increased from $50.0 million to $75 million. As of March 31, 2023, our consolidated total net leverage ratio was approximately 3.52x.

Although we are in compliance with our debt covenants as of March 31, 2023, we can make no assurance that we will remain in compliance with these ratios. Furthermore, we may need to refinance all or a portion of our indebtedness on or before maturity; however, we cannot provide assurance that we will be able to refinance any of our indebtedness on commercially reasonable terms or at all.

Capital Allocations

Principally due to the nature of our deicing business, our cash flows from operations have historically been seasonal, with the majority of our cash flows from operations generated during the first half of the calendar year. When we have not been able to meet our short-term liquidity or capital needs with cash from operations, whether as a result of the seasonality of our business or other causes, we have met those needs with borrowings under our revolving credit facility. We expect to meet the ongoing requirements for debt service, any declared dividends and capital expenditures from these sources. This, to a certain extent, is subject to general economic, financial, competitive, legislative, regulatory and other factors that are beyond our control.

We manage our capital allocation considering our long-term strategic objectives and required spending to sustain our business. During the first quarter of fiscal 2021, we reduced our dividend by approximately 80% to provide additional liquidity and align our capital allocation policy with our corporate strategy. While our equipment and facilities are generally not impacted by rapid technology changes, our operations require refurbishments and replacements to maintain structural integrity and reliable production and shipping capabilities. When possible, we incorporate efficiency, environmental and safety improvement capabilities into our routine capital projects and we plan the timing of larger projects to balance with our liquidity and capital resources. Changes in our operating cash flows may affect our future capital allocation and spending.

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During fiscal 2023, we expect to spend between $90 million and $100 million of sustaining capital in our Salt and Plant Nutrition businesses. Additionally, we continue to develop our recently identified lithium resource at our Ogden facility and have spent approximately $8.0 million of capital thus far in fiscal 2023 towards the development phase of this sustainable lithium development project. For the full year of fiscal 2023, we have allocated between $60 million to $75 million for further development. We expect to achieve market entry with a lithium product by 2025 and expect significant capital and other expenditures would be required to achieve this market entry; however, the full amount of this expenditure is currently unknown and will depend on a number of factors, including the outcome of further engineering and design plans. For more information, refer to Part I, Item 1A, “Risk Factors” in our Form 10-K for the for the annual period ended September 30, 2022.

On October 18, 2022, we received aggregate net proceeds of approximately $240.7 million, net of transaction costs, from Koch Minerals & Trading, LLC (“KM&T”) as part of a strategic equity partnership. We expect to use approximately $200 million of the proceeds from the private placement to advance the first development phase of the lithium project. We used the remaining $40.7 million of proceeds to reduce debt.

In connection with our strategy to strengthen and grow our essential minerals businesses, during the first and second quarters of fiscal 2022, we made $45 million equity investments in Fortress, building upon a previous $5 million investment. As of March 31, 2023, we have invested $50 million in Fortress in exchange for an ownership interest of approximately 45%. Fortress is a development stage company that is expected to achieve commercialization of its magnesium chloride-based fire-retardant products to help combat wildfires during fiscal 2023.

On May 5, 2023, we acquired the remaining 55% interest in Fortress consisting of an initial cash payment of approximately $26 million, approximately $28 million to be paid in cash and/or Compass Minerals common stock upon the achievement of certain performance measures, and a cash earn-out based on volumes of Fortress fire retardant products sold over a 10-year period. Building upon the previous 45% minority ownership stake in Fortress, the transaction provides us full ownership of all Fortress assets, contracts, and intellectual property.

The table below provides a summary of our cash flows by category, including cash flows from discontinued operations:

SIX MONTHS ENDED MARCH 31, 2023	SIX MONTHS ENDED MARCH 31, 2022
Operating Activities:
Net cash provided by operating activities were $143.9 million	Net cash provided by operating activities were $145.9 million
» Net losses were $21.9 million.	» Net losses were $9.7 million.
» Non-cash depreciation and amortization expense was $48.4 million.	» Non-cash depreciation and amortization expense was $56.2 million.
» Non-cash stock-based compensation expense was $13.7 million.	» Non-cash stock-based compensation expense was $7.8 million.
» Working capital items were a source of operating cash flows of $99.4 million.	» Working capital items were a source of operating cash flows of $61.3 million.
» Non-cash net loss in equity investees was $2.3 million.	» Non-cash net loss in equity investees was $2.1 million.
Investing Activities:
Net cash flows used in investing activities were $44.0 million	Net cash flows used in investing activities were $88.4 million
» Net cash flows used in investing activities included $43.7 million of capital expenditures.	» Net cash flows used in investing activities included equity method investments of $46.3 million.
	» Included $43.5 million of capital expenditures.
Financing Activities:
Net cash flows provided by financing activities were $102.9 million	Net cash flows used in financing activities were $25.9 million
» Included net payments on our debt of $123.1 million.	» Included net payments on our debt of $14.5 million.
» Included net proceeds from private placement of common stock of $240.7 million.	» Included the payment of dividends of $10.5 million.
» Included the payment of dividends of $12.6 million.

As mentioned above, our Salt segment’s business is seasonal and our Salt segment results and working capital needs are heavily impacted by the severity and timing of the winter weather, which generally occurs from December through March of each year. Customers tend to replenish their inventory prior to the start of the winter season and following snow events, consequently the number and timing of snow events during the winter season will impact the amount of our accounts receivable and inventory at

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the end of each quarter. Our cash flows during the six months ended March 31 of each year reflect the seasonal decrease in inventory due to the end of the winter season and a decrease in accounts receivable as winter season sales are collected.

Other Matters

See Item 1, Notes 8 and 10 of our Consolidated Financial Statements for a discussion regarding labor, environmental and litigation matters.

Reconciliation of Net Loss from Continuing Operations to EBITDA and Adjusted EBITDA

Management uses a variety of measures to evaluate our performance. While our consolidated financial statements, taken as a whole, provide an understanding of our overall results of operations, financial condition and cash flows, we analyze components of the consolidated financial statements to identify certain trends and evaluate specific performance areas. In addition to using U.S. GAAP financial measures, such as gross profit, net earnings and cash flows generated by operating activities, management uses EBITDA and Adjusted EBITDA. We have presented Adjusted EBITDA for both continuing operations and consolidated including discontinued operations for comparability purposes (see Item 1, Note 2 to our Consolidated Financial Statements for a discussion of discontinued operations). Both EBITDA and Adjusted EBITDA are non-GAAP financial measures used to evaluate the operating performance of our core business operations because our resource allocation, financing methods, cost of capital and income tax positions are managed at a corporate level, apart from the activities of the operating segments, and our operating facilities are located in different taxing jurisdictions, which can cause considerable variation in net earnings. We also use EBITDA and Adjusted EBITDA to assess our operating performance and return on capital against other companies, and to evaluate potential acquisitions or other capital projects. EBITDA and Adjusted EBITDA are not calculated under U.S. GAAP and should not be considered in isolation or as a substitute for net earnings, cash flows or other financial data prepared in accordance with U.S. GAAP or as a measure of our overall profitability or liquidity.

EBITDA and Adjusted EBITDA exclude interest expense, income taxes and depreciation and amortization, each of which are an essential element of our cost structure and cannot be eliminated. Furthermore, Adjusted EBITDA excludes other cash and non-cash items, including stock-based compensation, interest income, (gain) loss on foreign exchange, other (income) expense, net and other infrequent items that management does not consider indicative of normal operations. Other infrequent items, such as executive transition costs and restructuring charges, involve distinct initiatives that are not reflective of future operations and affect the comparability of our operational results across reporting periods. Our borrowings are a significant component of our capital structure and interest expense is a continuing cost of debt. We are also required to pay income taxes, a required and ongoing consequence of our operations. We have a significant investment in capital assets and depreciation and amortization reflect the utilization of those assets in order to generate revenues. Our employees are vital to our operations and we utilize various stock-based awards to compensate and incentivize our employees. Consequently, any measure that excludes these elements has material limitations. While EBITDA and Adjusted EBITDA are frequently used as measures of operating performance, these terms are not necessarily comparable to similarly titled measures of other companies due to the potential inconsistencies in the method of calculation. 

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The calculation of EBITDA and Adjusted EBITDA as used by management is set forth in the table below (in millions):

	Three Months Ended March 31,				Six Months Ended March 31,
	2023		2022		2023		2022
Net loss from continuing operations	$	(21.6)	$	(29.0)	$	(21.9)	$	(21.1)
Interest expense	14.2		13.9		28.1		27.8
Income tax expense	55.1		30.4		67.0		29.2
Depreciation, depletion and amortization	24.5		27.9		48.4		56.2
EBITDA from continuing operations	72.2		43.2		121.6		92.1
Adjustments to EBITDA from continuing operations:
Stock-based compensation - non cash	3.1		4.5		13.7		7.7
Interest income	(1.9)		—		(3.0)		(0.3)
(Gain) loss on foreign exchange	(0.2)		3.0		2.3		2.6
Executive transition costs(a)	—		0.5		—		4.3
Restructuring charges(b)	3.7		—		3.7		—
Accrued loss and legal costs related to SEC investigation(c)	(0.4)		13.6		(0.1)		16.7
Other expense, net	0.9		—		1.0		0.1
Adjusted EBITDA from continuing operations	77.4		64.8		139.2		123.2
Adjusted EBITDA from discontinued operations	—		7.3		—		15.9
Adjusted EBITDA including discontinued operations	$	77.4	$	72.1	$	139.2	$	139.1

(a)We incurred severance and other costs related to executive transition.

(b)We incurred severance and related charges related to a reduction of its workforce.

(c)We recognized costs, net of reimbursements, related to the settled SEC investigation.

Recent Accounting Pronouncements    

See Part 1, Note 1 of our Consolidated Financial Statements for a discussion of recent accounting pronouncements.

Effects of Currency Fluctuations and Inflation

Our operations outside of the U.S. are conducted primarily in Canada and the U.K. Therefore, our results of operations are subject to both currency transaction risk and currency translation risk. We incur currency transaction risk whenever we or one of our subsidiaries enters into either a purchase or sales transaction using a currency other than the local currency of the transacting entity. With respect to currency translation risk, our financial condition and results of operations are measured and recorded in the relevant local currency and then translated into U.S. dollars for inclusion in our historical consolidated financial statements. Exchange rates between these currencies and the U.S. dollar have fluctuated significantly from time to time and may do so in the future. The majority of revenues and costs are denominated in U.S. dollars, with Canadian dollars and British pounds sterling also being significant. Significant changes in the value of the Canadian dollar or British pound sterling relative to the U.S. dollar could have a material adverse effect on our financial condition and our ability to meet interest and principal payments on U.S. dollar-denominated debt, including borrowings under our senior secured credit facilities.

We are experiencing increases in logistics costs, prices for energy and other costs that have only been partially recovered through price increases for our products. We estimate that the impact of inflation increased logistics costs by approximately $2 million to $4 million for the three months ended March 31, 2023 and $9 million to $11 million for the six months ended March 31, 2023, and product costs by approximately $4 million to $6 million for the three months ended March 31, 2023 and $8 million to $10 million six months ended March 31, 2023). Our efforts to recover inflation-based cost increases from our customers may be hampered as a result of the structure of our contracts and the contract bidding process as well as the competitive industries, economic conditions and countries in which we operate. For more information, see Part I, Item 1A, “Risk Factors” in our Annual Report on Form 10-K for the annual period ended September 30, 2022 and Part II, Item 1A, “Risk Factors” in our Quarterly Report on Form 10-Q for the quarter ended March 31, 2023.

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Seasonality

We experience a substantial amount of seasonality in our sales, including our salt deicing product sales. Consequently, our Salt segment sales and operating income are generally higher in the first and second fiscal quarters (ending December 31 and March 31) and lower during the third and fourth fiscal quarters of each year (ending June 30 and September 30). In particular, sales of highway and consumer deicing salt and magnesium chloride products vary based on the severity of the winter conditions in areas where the product is used. Following industry practice in North America and the U.K., we seek to stockpile sufficient quantities of deicing salt throughout the first, third and fourth fiscal quarters (ending December 31, June 30 and September 30) to meet the estimated requirements for the winter season. Our plant nutrition business is also seasonal. As a result, we and our customers generally build inventories during the plant nutrition business’ low demand periods of the year (which are typically winter and summer, but can vary due to weather and other factors) to ensure timely product availability during the peak sales seasons (which are typically spring and autumn, but can also vary due to weather and other factors).

Climate Change

The potential impact of climate change on our operations, product demand and the needs of our customers remains uncertain. Significant changes to weather patterns, a reduction in average snowfall or regional drought within our served markets or at our Ogden facility could negatively impact customer demand for our products and our costs, as well as our ability to produce our products. For example, prolonged periods of mild winter weather could reduce the demand for our deicing products. Drought or excessive precipitation could similarly impact demand for our SOP products, as well as continue to impact the amount and quality of feedstock used to produce SOP at our Ogden facility due to changes in brine levels, mineral concentrations or other factors, which could have a material impact on our Plant Nutrition results of operations. Climate change could also lead to disruptions in the production or distribution of our products due to major storm events or prolonged adverse conditions, changing temperature levels, lake level fluctuations or flooding from sea level changes. Climate change or governmental initiatives to address climate change may affect our operations and necessitate capital expenditures in the future, although capital expenditures for climate-related projects are not expected to be material in fiscal 2023. For more information, see Part I, Item 1A, “Risk Factors” and Part I, Item 1 “Business—Environmental, Health and Safety and Other Regulatory Matters” in our Annual Report on Form 10-K for the annual period ended September 30, 2022.

Global Economy

The COVID-19 pandemic has negatively impacted the global economy, disrupted global supply chains and created significant volatility and disruption of financial markets. We have continued producing and delivering essential products that support critical industries such as transportation, agriculture, chemical, food, pharmaceutical and animal nutrition. We have instituted several measures in response to the COVID-19 pandemic and have experienced negative impacts to our business from COVID-19, but our results of operations for the three and six months ended March 31, 2023, and 2022, were not materially affected by COVID-19, although the recent supply chain shortages and cost increases may be linked to COVID-19. Also, while we have no operations in Russia or Ukraine, we are continuing to monitor any broader impact from the current war in Ukraine, particularly with respect to energy costs and implications on global fertilizer market supply and demand conditions. The ultimate impact that any infectious outbreak or the war in Ukraine will have on our future results is unknown at this time. For more information, see Part I, Item 1A, “Risk Factors” in our Annual Report on Form 10-K for the annual period ended September 30, 2022.

Item 3.    Quantitative and Qualitative Disclosures About Market Risk

Our business is subject to various types of market risks that include interest rate risk, foreign currency exchange rate risk and commodity pricing risk. Management has taken actions to mitigate our exposure to commodity pricing and foreign currency exchange rate risk by entering into natural gas derivative instruments and foreign currency contracts. We may take further actions to mitigate our exposure to interest rates, exchange rates and changes in the cost of fuel consumed at our production locations or the cost of transporting our products due to variations in our contracted carriers’ cost of fuel, which is typically diesel fuel. However, there can be no assurance that our hedging activities will eliminate or substantially reduce these risks. We do not enter into any financial instrument arrangements for speculative purposes. Our market risk exposure related to these items has not changed materially since September 30, 2022.

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Item 4.    Controls and Procedures

Disclosure Controls and Procedures

The Company maintains disclosure controls and procedures that are designed to provide reasonable assurance that information required to be disclosed in our reports under the Securities Exchange Act of 1934, as amended (the “Exchange Act”), is recorded, processed, summarized and reported within the time periods specified in the SEC’s rules and forms, and that such information is accumulated and communicated to management, including our President and Chief Executive Officer, Chief Financial Officer and Chief Accounting Officer, as appropriate, to allow timely decisions regarding required disclosure. In designing and evaluating the disclosure controls and procedures, management recognizes that any controls and procedures, no matter how well designed and operated, can provide only reasonable assurance of achieving the desired control objectives. Due to the inherent limitations in all control systems, no evaluation of controls can provide absolute assurance that misstatements due to error or fraud will not occur or that all control issues and instances of fraud, if any, within the Company have been detected.

In connection with the preparation of this Quarterly Report on Form 10-Q, an evaluation of the effectiveness of the design and operation of our disclosure controls and procedures (as defined in Rule 13a-15(e) under the Exchange Act) was performed under the supervision and with the participation of the Company’s management, including the Chief Executive Officer and Chief Financial Officer. Based on that evaluation, the Chief Executive Officer and Chief Financial Officer concluded that our disclosure controls and procedures were ineffective as of March 31, 2023, due to the material weaknesses described below.

1.During the fourth quarter ended September 30, 2022, the Company identified a material weakness in the design and operating effectiveness of information technology general controls (“ITGCs”) related to certain systems that support the Company’s internal controls over financial reporting. Specifically, the Company did not maintain effective controls over privileged user access to certain systems. Automated and manual business process controls were therefore also deemed ineffective because they could have been adversely impacted by the ineffective ITGCs.

2.    During the fourth quarter ended September 30, 2022, the Company identified a material weakness in the design and operating effectiveness of controls related to the sales process. Specifically, the Company did not maintain effective controls over pricing and order entry.

3.    During the fourth quarter ended September 30, 2022, a material weakness was identified in the design and operating effectiveness of controls related to the existence of inventory held at certain locations.

A material weakness, as defined in Rule 12b-2 under the Exchange Act, is a deficiency, or a combination of deficiencies, in internal control over financial reporting, such that there is a reasonable possibility that a material misstatement of the Company’s annual or interim consolidated financial statements will not be prevented or detected on a timely basis. Notwithstanding such material weaknesses in internal control over financial reporting, our Chief Executive Officer and Chief Financial Officer have concluded that the Company’s consolidated financial statements included in this Quarterly Report on Form 10-Q present fairly, in all material respects, our financial position, results of operations and cash flows for the periods presented in conformity with U.S. GAAP.

Remediation of Material Weaknesses

The Company has further defined and enhanced its management review attributes and increased the frequency of its privileged access reviews. Testing of these controls over privileged user access is currently underway.

The Company continues to assess and is in the process of enhancing and implementing certain internal controls over the sales and inventory processes in accordance with the remediation plans for those material weaknesses. Further enhancements related to inventory existence, sales pricing, and order entry are underway. These enhanced controls will be tested for effectiveness in future periods.

Changes in Internal Control Over Financial Reporting

Other than the matters noted above, there were no changes in the Company’s internal control over financial reporting during the most recently completed fiscal quarter that have materially affected, or are reasonably likely to materially affect, the Company’s internal control over financial reporting.

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PART II. OTHER INFORMATION

Item 1.    Legal Proceedings

We are involved in the legal proceedings described in Part I, Item 1, Note 8 and Part I, Item 1, Note 10 of our Consolidated Financial Statements and, from time to time, various routine legal proceedings and claims arising from the ordinary course of our business. These primarily involve tax assessments, disputes with former employees and contract labor, commercial claims, product liability claims, personal injury claims and workers’ compensation claims. Management cannot predict the outcome of legal proceedings and claims with certainty. Nevertheless, management believes that the outcome of legal proceedings and claims, which are pending or known to be threatened, even if determined adversely, will not, either individually or in the aggregate, have a material adverse effect on our results of operations, cash flows or financial condition, except as otherwise described in Part I, Item 1, Note 8 and Part I, Item 1, Note 10 of our Consolidated Financial Statements. There have been no material developments since September 30, 2022 with respect to our legal proceedings, except as described in Part I, Item 1, Note 8 and Part I, Item 1, Note 10 of our Consolidated Financial Statements.

Item 1A.    Risk Factors

For a discussion of the risk factors applicable to Compass Minerals, please refer to Part I, Item 1A, “Risk Factors” in our Annual Report on Form 10-K for the annual period ended September 30, 2022, as updated and supplemented by the discussion below.

Operations at our Ogden, Utah, facility are dependent on ambient brine from the Great Salt Lake, and changes in lake brine levels or any limitations on our continued ability to access ambient lake brine in the Great Salt Lake could adversely affect us.

Our Ogden facility produces SOP, salt and magnesium chloride products from the high mineral concentrations within the ambient lake brine in the Great Salt Lake. In addition, we are developing our identified lithium resource at our Ogden facility and the Great Salt Lake. Our ability to produce SOP, salt and magnesium chloride, as well as any future production of lithium, at our Ogden facility, is dependent upon, among other matters, sufficient lake elevations in the Great Salt Lake and our continued ability to maintain, renew or acquire the permits, licenses and approvals required to access ambient lake brine in the Great Salt Lake.

In recent years, sustained drought (as a result of climate change or otherwise) has lowered lake levels and increased mineral concentrations in the Great Salt Lake. If this continues, lower lake levels could impact mineral composition and our mineral harvesting process, amount and timing. Lake level fluctuations and other factors, including recent legislative actions in Utah or other state or federal actions to manage the salinity of the Great Salt Lake, could alter north arm lake levels and may disrupt our evaporation production cycle, impact our access to ambient lake brine in the Great Salt Lake or increase our capital expenditures and production costs.

The expansion of existing operations or production capacity at our Ogden facility, or preservation of existing rights in some cases, is also predicated upon securing any necessary permits, licenses and approvals. For example, we may require additional permits, licenses and approvals to continue diverting water from the Great Salt Lake to further expand our production capacity at our Ogden facility and continue the development of our identified lithium resource.

Item 2.    Unregistered Sales of Equity Securities and Use of Proceeds

On September 14, 2022, we entered into a Stock Purchase Agreement with KM&T, a subsidiary of Koch Industries, Inc., pursuant to which we agreed to issue and sell 6,830,700 shares of our common stock at a purchase price of $36.87 for aggregate net proceeds of approximately $240.7 million, net of transaction costs. On October 18, 2022, we closed the direct private placement with KM&T, through its affiliate KM&T Investment Holdings, LLC, resulting in their ownership of approximately 17% of our outstanding common stock. We expect to use approximately $200 million of the proceeds from the private placement to advance the first development phase of our sustainable lithium development project at our Ogden site. We used the remaining $40.7 million of proceeds to reduce debt. As part of the Stock Purchase Agreement, KM&T has appointed two members to our board of directors, effective November 13, 2022. Refer to Part I, Item 1, Note 16 for additional details.

The issuance of the shares was exempt from registration pursuant to the exemption for transactions by an issuer not involving any public offering under Section 4(a)(2) of the Securities Act of 1933, as amended (the “Securities Act”). The Investor

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represented to the Company that it is an “accredited investor” as defined in Rule 501 of the Securities Act and that the shares are being acquired solely for investment and with no intention to distribute, and appropriate legends will be affixed to any certificates evidencing any shares.

Perella Weinberg Partners LP acted as sole financial advisor to Compass Minerals in the transaction and Cleary Gottlieb Steen & Hamilton LLP acted as our legal advisor. Jones Day acted as legal advisor for KM&T.

Item 3.    Defaults Upon Senior Securities

None.

Item 4.    Mine Safety Disclosures

Information concerning mine safety violations or other regulatory matters required by Section 1503(a) of the Dodd-Frank Wall Street Reform and Consumer Protection Act and Item 104 of Regulation S-K is included in Exhibit 95 to this Quarterly Report on Form 10-Q.

Item 5.    Other Information

None.

Item 6.    Exhibits

Exhibit No.	Exhibit Description
10.1	Amendment and Restatement Agreement to the Credit Agreement, dated as of May 5, 2023, by and among Compass Minerals International, Inc., Compass Minerals Canada Corp., Compass Minerals UK Limited, the Lenders party thereto and JPMorgan Chase Bank, N.A., as Administrative Agent (incorporated by reference to Exhibit 10.1 to Compass Minerals International, Inc.’s Current Report on Form 8-K filed on May 5, 2023).
31.1*	Section 302 Certifications of Kevin S. Crutchfield, President and Chief Executive Officer.
31.2*	Section 302 Certifications of Lorin Crenshaw, Chief Financial Officer.
32**	Certification Pursuant to 18 U.S.C. §1350 of Kevin S. Crutchfield, President and Chief Executive Officer, and Lorin Crenshaw, Chief Financial Officer.
95*	Mine Safety Disclosures.
101**	The following financial statements from the Company’s Quarterly Report on Form 10-Q for the quarter ended March 31, 2023, formatted in Inline Extensible Business Reporting Language (iXBRL): (i) Consolidated Balance Sheets, (ii) Consolidated Statements of Operations, (iii) Consolidated Statements of Comprehensive Loss, (iv) Consolidated Statements of Stockholders’ Equity, (v) Consolidated Statements of Cash Flows, and (vi) the Notes to the Consolidated Financial Statements.
104	Cover Page Interactive Data File (contained in Exhibit 101).
*    Filed herewith
**    Furnished herewith

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SIGNATURES

Pursuant to the requirements of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned, thereunto duly authorized.

	COMPASS MINERALS INTERNATIONAL, INC.
Date: May 9, 2023	By:	/s/ Lorin Crenshaw
		Lorin Crenshaw
		Chief Financial Officer
		(Principal Financial Officer)

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EX-31.1

Exhibit 31.1

CERTIFICATION

I, Kevin S. Crutchfield, certify that:

1.I have reviewed this quarterly report on Form 10-Q of Compass Minerals International, Inc.;

2.Based on my knowledge, this report does not contain any untrue statement of a material fact or omit to state a material fact necessary to make the statements made, in light of the circumstances under which such statements were made, not misleading with respect to the period covered by this report;

3.Based on my knowledge, the financial statements, and other financial information included in this report, fairly present in all material respects the financial condition, results of operations and cash flows of the registrant as of, and for, the periods presented in this report;

4.The registrant’s other certifying officer and I are responsible for establishing and maintaining disclosure controls and procedures (as defined in Exchange Act Rules 13a-15(e) and 15d-15(e)) and internal control over financial reporting (as defined in Exchange Act Rules 13a-15(f) and 15d-15(f)) for the registrant and have:

(a)designed such disclosure controls and procedures, or caused such disclosure controls and procedures to be designed under our supervision, to ensure that material information relating to the registrant, including its consolidated subsidiaries, is made known to us by others within those entities, particularly during the period in which this report is being prepared;

(b)designed such internal control over financial reporting, or caused such internal control over financial reporting to be designed under our supervision, to provide reasonable assurance regarding the reliability of financial reporting and the preparation of financial statements for external purposes in accordance with generally accepted accounting principles;

(c)evaluated the effectiveness of the registrant’s disclosure controls and procedures and presented in this report our conclusions about the effectiveness of the disclosure controls and procedures, as of the end of the period covered by this report based on such evaluation; and

(d)disclosed in this report any change in the registrant’s internal control over financial reporting that occurred during the registrant’s most recent fiscal quarter (the registrant’s fourth fiscal quarter in the case of an annual report) that has materially affected, or is reasonably likely to materially affect, the registrant’s internal control over financial reporting; and

5.The registrant’s other certifying officer and I have disclosed, based on our most recent evaluation of internal control over financial reporting, to the registrant’s auditors and the audit committee of the registrant’s board of directors (or persons performing the equivalent functions):

(a)all significant deficiencies and material weaknesses in the design or operation of internal control over financial reporting which are reasonably likely to adversely affect the registrant’s ability to record, process, summarize and report financial information; and

(b)any fraud, whether or not material, that involves management or other employees who have a significant role in the registrant’s internal control over financial reporting.

Date: May 9, 2023	By:	/s/ Kevin S. Crutchfield
		Kevin S. Crutchfield
		President and Chief Executive Officer

EX-31.2

Exhibit 31.2

CERTIFICATION

I, Lorin Crenshaw, certify that:

1.I have reviewed this quarterly report on Form 10-Q of Compass Minerals International, Inc.;

2.Based on my knowledge, this report does not contain any untrue statement of a material fact or omit to state a material fact necessary to make the statements made, in light of the circumstances under which such statements were made, not misleading with respect to the period covered by this report;

3.Based on my knowledge, the financial statements, and other financial information included in this report, fairly present in all material respects the financial condition, results of operations and cash flows of the registrant as of, and for, the periods presented in this report;

4.The registrant’s other certifying officer and I are responsible for establishing and maintaining disclosure controls and procedures (as defined in Exchange Act Rules 13a-15(e) and 15d-15(e)) and internal control over financial reporting (as defined in Exchange Act Rules 13a-15(f) and 15d-15(f)) for the registrant and have:

(a)designed such disclosure controls and procedures, or caused such disclosure controls and procedures to be designed under our supervision, to ensure that material information relating to the registrant, including its consolidated subsidiaries, is made known to us by others within those entities, particularly during the period in which this report is being prepared;

(b)designed such internal control over financial reporting, or caused such internal control over financial reporting to be designed under our supervision, to provide reasonable assurance regarding the reliability of financial reporting and the preparation of financial statements for external purposes in accordance with generally accepted accounting principles;

(c)evaluated the effectiveness of the registrant’s disclosure controls and procedures and presented in this report our conclusions about the effectiveness of the disclosure controls and procedures, as of the end of the period covered by this report based on such evaluation; and

(d)disclosed in this report any change in the registrant’s internal control over financial reporting that occurred during the registrant’s most recent fiscal quarter (the registrant’s fourth fiscal quarter in the case of an annual report) that has materially affected, or is reasonably likely to materially affect, the registrant’s internal control over financial reporting; and

5.The registrant’s other certifying officer and I have disclosed, based on our most recent evaluation of internal control over financial reporting, to the registrant’s auditors and the audit committee of the registrant’s board of directors (or persons performing the equivalent functions):

(a)all significant deficiencies and material weaknesses in the design or operation of internal control over financial reporting which are reasonably likely to adversely affect the registrant’s ability to record, process, summarize and report financial information; and

(b)any fraud, whether or not material, that involves management or other employees who have a significant role in the registrant’s internal control over financial reporting.

Date: May 9, 2023	By:	/s/ Lorin Crenshaw
		Lorin Crenshaw
		Chief Financial Officer

EX-32

Exhibit 32

CERTIFICATION PURSUANT TO 18 U.S.C. §1350

Each of the undersigned hereby certifies that this quarterly report on Form 10-Q for the period ended March 31, 2023, as filed with the Securities and Exchange Commission on the date hereof, based on my knowledge, fully complies with the requirements of Section 13(a) or 15(d) of the Securities Exchange Act of 1934 and that the information contained in this report fairly presents, in all material respects, the financial condition and results of operations of Compass Minerals International, Inc.

Date: May 9, 2023	By:	/s/ Kevin S. Crutchfield
		Kevin S. Crutchfield
		President and Chief Executive Officer
Date: May 9, 2023	By:	/s/ Lorin Crenshaw
		Lorin Crenshaw
		Chief Financial Officer

EX-95

Exhibit 95

MINE SAFETY DISCLOSURE

We understand that to prevent employee and contractor injuries, we must approach safety excellence from many directions at once. We utilize a multi-faceted approach towards world class safety performance. This approach includes (1) setting a high standard of risk mitigation, (2) having robust safety management systems, and (3) supporting a culture of full engagement and personal accountability at all levels of the organization.

We continuously monitor our safety performance by assessing injury and non-injury incidents (e.g., near misses/near hits) as well as key performance indicators. We believe our approach to safety excellence will help us deliver on our commitment to our employees, contractors, their families and our customers to provide a safe working environment.

Mine Safety Data

A subsidiary of Compass Minerals International, Inc. owns and operates the Cote Blanche mine, an underground salt mine located in St. Mary Parish, Louisiana. The Cote Blanche mine is subject to regulation by the Mine Safety and Health Administration (“MSHA”) under the Federal Mine Safety and Health Act of 1977, as amended (the “Mine Act”).

MSHA is required to regularly inspect the Cote Blanche mine and issue a citation, or take other enforcement action, if an inspector or authorized representative believes that a violation of the Mine Act or MSHA’s standards or regulations has occurred. MSHA is required to propose a civil penalty for each alleged violation that it cites.

We have the option to legally contest any enforcement action or related penalty we receive. As a result of this process, an enforcement action may be modified or vacated and any civil penalty proposed by MSHA for an alleged violation may be increased, reduced or eliminated. However, under the Mine Act, we are required to abate (or correct) each alleged violation within a specified time period, regardless of whether we contest the alleged violation.

The table below sets forth information for the quarterly period ended March 31, 2023 concerning certain mine safety violations and other regulatory matters pursuant to requirements under the Dodd-Frank Wall Street Reform and Consumer Protection Act and Securities and Exchange Commission rules and regulations. The information only applies to our operations regulated by the U.S. Mine Safety and Health Administration.

Mine Name/ Mine I.D. Number	Section 104 S&S Citations & Orders1	Section 104(b) Orders2	Section 104(d) Citations & Orders3	Section 110(b)(2) Violations4	Section 107(a) Orders5	Total Dollar Value of MSHA Proposed Assessments (Actual Amount)	Total Number of Mining Related Fatalities	Received Notice of Pattern of Violations under Section 104(e) (Yes/No)6	Legal Actions Pending as of Last Day of Period	Legal Actions Initiated During Period	Legal Actions Resolved During Period
Cote Blanche Mine/16-00358	12	0	0	0	0	$28,467	0	No	0	0	0

1 Represents the number of citations and orders issued under Section 104 of the Mine Act for alleged violations of mandatory health or safety standards that could significantly and substantially contribute to a mine health and safety hazard. The number reported includes no orders alleging an S&S violation issued under Section 104(g) of the Mine Act.

2 Represents the number of orders issued under Section 104(b) of the Mine Act for alleged failures to abate a citation issued under Section 104(a) of the Mine Act within the time period specified in the citation.

3 Represents the number of citations and orders issued under Section 104(d) of the Mine Act for alleged unwarrantable failures (aggravated conduct constituting more than ordinary negligence) to comply with mandatory safety or health standards.

4 Represents the number of violations issued under section 110(b)(2) of the Mine Act for alleged “flagrant” failures (reckless or repeated failures) to make reasonable efforts to eliminate a known violation of a mandatory safety or health standard that substantially proximately caused, or reasonably could have been expected to cause, death or serious bodily injury.

5 Represents the number of orders issued under Section 107(a) of the Mine Act for alleged conditions or practices which could reasonably be expected to cause death or serious physical harm before the condition or practice can be abated.

6 Section 104(e) written notices are issued for an alleged pattern of violating mandatory health or safety standards that could significantly and substantially contribute to a mine safety or health hazard.

2

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Cover Page - shares	6 Months Ended
	Mar. 31, 2023	May 05, 2023
Cover [Abstract]
Document Type	10-Q
Document Quarterly Report	true
Document Period End Date	Mar. 31, 2023
Document Transition Report	false
Entity File Number	001-31921
Entity Registrant Name	Compass Minerals International, Inc.
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	36-3972986
Entity Address, Address Line One	9900 West 109th Street
Entity Address, Address Line Two	Suite 100
Entity Address, City or Town	Overland Park
Entity Address, State or Province	KS
Entity Address, Postal Zip Code	66210
City Area Code	913
Local Phone Number	344-9200
Title of 12(b) Security	Common stock, $0.01 par value
Trading Symbol	CMP
Security Exchange Name	NYSE
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Large Accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Shell Company	false
Entity Common Stock, Shares Outstanding		41,139,343
Entity Central Index Key	0001227654
Current Fiscal Year End Date	--09-30
Document Fiscal Year Focus	2023
Document Fiscal Period Focus	Q2
Amendment Flag	false

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CONSOLIDATED BALANCE SHEETS - USD ($) $ in Millions	Mar. 31, 2023	Sep. 30, 2022
Current assets:
Cash and cash equivalents	$ 249.7	$ 46.1
Receivables, less allowance for doubtful accounts of $3.1 at March 31, 2023 and $3.4 at September 30, 2022	159.7	167.2
Inventories	261.7	304.4
Other	29.7	44.3
Total current assets	700.8	562.0
Property, plant and equipment, net	782.6	776.6
Intangible assets, net	44.9	45.4
Goodwill	56.9	56.4
Equity method investments	44.3	46.6
Other	155.2	156.5
Total assets	1,784.7	1,643.5
Current liabilities:
Current portion of long-term debt	0.0	0.0
Accounts payable	114.9	114.7
Accrued salaries and wages	18.7	22.2
Income taxes payable	51.1	1.0
Accrued interest	14.1	14.1
Accrued expenses and other current liabilities	77.2	81.1
Total current liabilities	276.0	233.1
Long-term debt, net of current portion	825.7	947.6
Deferred income taxes, net	60.7	63.4
Other noncurrent liabilities	136.9	143.0
Commitments and contingencies (Note 10)
Stockholders’ equity:
Common stock: $0.01 par value, 200,000,000 authorized shares; 42,197,964 issued shares at March 31, 2023 and 35,367,264 issued shares at September 30, 2022	0.4	0.4
Additional paid-in capital	406.2	152.1
Treasury stock, at cost — 1,058,621 shares at March 31, 2023 and 1,196,300 shares at September 30, 2022	(8.6)	(7.3)
Retained earnings	192.0	226.5
Accumulated other comprehensive loss	(104.6)	(115.3)
Total stockholders’ equity	485.4	256.4
Total liabilities and stockholders’ equity	$ 1,784.7	$ 1,643.5

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CONSOLIDATED BALANCE SHEETS (Parenthetical) - USD ($) $ in Millions	Mar. 31, 2023	Sep. 30, 2022
ASSETS
Allowance for doubtful accounts	$ 3.1	$ 3.4
Stockholders’ equity:
Common stock, par or stated value per share (in dollars per share)	$ 0.01	$ 0.01
Common stock, shares authorized (in shares)	200,000,000	200,000,000
Common stock, shares issued (in shares)	42,197,964	35,367,264
Treasury stock, shares (in shares)	1,058,621	1,196,300

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CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($) shares in Thousands, $ in Millions	3 Months Ended		6 Months Ended
	Mar. 31, 2023	Mar. 31, 2022	Mar. 31, 2023	Mar. 31, 2022
Sales	$ 411.1	$ 448.5	$ 763.5	$ 780.0
Gross profit	85.2	64.6	155.2	124.5
Selling, general and administrative expenses	37.3	44.6	79.4	84.1
Operating earnings	47.9	20.0	75.8	40.4
Other (income) expense:
Interest income	(1.9)	0.0	(3.0)	(0.3)
Interest expense	14.2	13.9	28.1	27.8
(Gain) loss on foreign exchange	(0.2)	3.0	2.3	2.6
Net loss in equity investee	1.4	1.7	2.3	2.1
Other expense, net	0.9	0.0	1.0	0.1
Earnings from continuing operations before income taxes	33.5	1.4	45.1	8.1
Income tax expense from continuing operations	55.1	30.4	67.0	29.2
Net loss from continuing operations	(21.6)	(29.0)	(21.9)	(21.1)
Net earnings from discontinued operations	0.0	16.9	0.0	11.4
Net loss	$ (21.6)	$ (12.1)	$ (21.9)	$ (9.7)
Basic net loss from continuing operations per common share (in dollars per share)	$ (0.53)	$ (0.85)	$ (0.55)	$ (0.62)
Basic net earnings from discontinued operations per common share (in dollars per share)	0	0.49	0	0.33
Basic net loss per common share (in dollars per share)	(0.53)	(0.36)	(0.55)	(0.29)
Diluted net loss from continuing operations per common share (in dollars per share)	(0.53)	(0.85)	(0.55)	(0.62)
Diluted net earnings from discontinued operations per common share (in dollars per share)	0	0.49	0	0.33
Diluted net loss per common share (in dollars per share)	$ (0.53)	$ (0.36)	$ (0.55)	$ (0.29)
Weighted-average common shares outstanding (in thousands):
Basic (in shares)	41,110	34,103	40,423	34,081
Diluted (in shares)	41,110	34,113	40,423	34,100
Shipping and handling cost
Cost	$ 130.1	$ 160.1	$ 237.5	$ 255.8
Product cost
Cost	$ 195.8	$ 223.8	$ 370.8	$ 399.7

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CONSOLIDATED STATEMENTS OF COMPREHENSIVE LOSS - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Mar. 31, 2023	Mar. 31, 2022	Mar. 31, 2023	Mar. 31, 2022
Statement of Comprehensive Income [Abstract]
Net loss	$ (21.6)	$ (12.1)	$ (21.9)	$ (9.7)
Other comprehensive income (loss):
Unrealized gain from change in pension obligations, net of tax of $0.0 for the three and six months ended March 31, 2023 and 2022	0.0	0.1	0.1	0.2
Unrealized (loss) gain on cash flow hedges, net of tax of $0.0 and $(0.3) for the three and six months ended March 31, 2023, respectively, and $0.4 for both the three and six months ended March 31, 2022	(1.1)	1.0	(3.9)	(1.0)
Cumulative translation adjustment	2.8	10.7	14.5	6.9
Comprehensive loss	$ (19.9)	$ (0.3)	$ (11.2)	$ (3.6)

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CONSOLIDATED STATEMENTS OF COMPREHENSIVE LOSS (Parenthetical) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Mar. 31, 2023	Mar. 31, 2022	Mar. 31, 2023	Mar. 31, 2022
Statement of Comprehensive Income [Abstract]
Unrealized gain from change in pension obligations, tax	$ 0.0	$ 0.0	$ 0.0	$ 0.0
Unrealized gain (loss) on cash flow hedges, tax	$ 0.0	$ 0.4	$ (0.3)	$ 0.4

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CONSOLIDATED STATEMENTS OF STOCKHOLDERS' EQUITY - USD ($) $ in Millions	Total	Common Stock	Additional Paid-In Capital	Treasury Stock	Retained Earnings	Accumulated Other Comprehensive (Loss) Income
Beginning balance at Sep. 30, 2021	$ 293.1	$ 0.4	$ 136.3	$ (5.5)	$ 272.4	$ (110.5)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Comprehensive (loss) income	(3.3)				2.4	(5.7)
Dividends on common stock	(5.3)		(0.1)		(5.2)
Stock options exercised, net of shares withheld for taxes	0.2		0.2
Stock-based compensation	3.3		3.3
Ending balance at Dec. 31, 2021	288.0	0.4	139.7	(5.5)	269.6	(116.2)
Beginning balance at Sep. 30, 2021	293.1	0.4	136.3	(5.5)	272.4	(110.5)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Comprehensive (loss) income	(3.6)
Ending balance at Mar. 31, 2022	286.5	0.4	144.1	(5.9)	252.3	(104.4)
Beginning balance at Dec. 31, 2021	288.0	0.4	139.7	(5.5)	269.6	(116.2)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Comprehensive (loss) income	(0.3)				(12.1)	11.8
Dividends on common stock	(5.2)				(5.2)
Shares issued for stock units, net of shares withheld for taxes	(0.5)		(0.1)	(0.4)
Stock-based compensation	4.5		4.5
Ending balance at Mar. 31, 2022	286.5	0.4	144.1	(5.9)	252.3	(104.4)
Beginning balance at Sep. 30, 2022	256.4	0.4	152.1	(7.3)	226.5	(115.3)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Comprehensive (loss) income	8.7				(0.3)	9.0
Dividends on common stock	(6.3)				(6.3)
Private placement of common stock	240.7		240.7
Shares issued for stock units, net of shares withheld for taxes	(0.3)			(0.3)
Stock-based compensation	10.6		10.6
Ending balance at Dec. 31, 2022	509.8	0.4	403.4	(7.6)	219.9	(106.3)
Beginning balance at Sep. 30, 2022	256.4	0.4	152.1	(7.3)	226.5	(115.3)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Comprehensive (loss) income	(11.2)
Ending balance at Mar. 31, 2023	485.4	0.4	406.2	(8.6)	192.0	(104.6)
Beginning balance at Dec. 31, 2022	509.8	0.4	403.4	(7.6)	219.9	(106.3)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Comprehensive (loss) income	(19.9)				(21.6)	1.7
Dividends on common stock	(6.3)				(6.3)
Shares issued for stock units, net of shares withheld for taxes	(1.3)		(0.3)	(1.0)
Stock-based compensation	3.1		3.1
Ending balance at Mar. 31, 2023	$ 485.4	$ 0.4	$ 406.2	$ (8.6)	$ 192.0	$ (104.6)

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CONSOLIDATED STATEMENTS OF STOCKHOLDERS' EQUITY (Parenthetical) - $ / shares	3 Months Ended
	Mar. 31, 2023	Dec. 31, 2022	Mar. 31, 2022	Dec. 31, 2021
Statement of Stockholders' Equity [Abstract]
Cash dividends per share (in dollars per share)	$ 0.15	$ 0.15	$ 0.15	$ 0.15

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CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Millions	6 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
Cash flows from operating activities:
Net loss	$ (21.9)	$ (9.7)
Adjustments to reconcile net loss to net cash flows provided by operating activities:
Depreciation, depletion and amortization	48.4	56.2
Amortization of deferred financing costs	1.5	1.5
Stock-based compensation	13.7	7.8
Deferred income taxes	(4.2)	16.2
Unrealized foreign exchange loss (gain)	2.3	(15.2)
Loss on impairment of long-lived assets	0.0	24.7
Net loss in equity investees	2.3	2.1
Other, net	2.4	1.0
Changes in operating assets and liabilities:
Receivables	8.9	(63.7)
Inventories	44.1	108.9
Other assets	18.4	(9.0)
Accounts payable and accrued expenses and other current liabilities	35.6	25.9
Other liabilities	(7.6)	(0.8)
Net cash provided by operating activities	143.9	145.9
Net cash used in investing activities
Capital expenditures	(43.7)	(43.5)
Investments in equity method investees	0.0	(46.3)
Other, net	(0.3)	1.4
Net cash used in investing activities	(44.0)	(88.4)
Cash flows from financing activities:
Proceeds from revolving credit facility borrowings	16.7	221.3
Principal payments on revolving credit facility borrowings	(168.2)	(280.7)
Proceeds from issuance of long-term debt	37.5	50.8
Principal payments on long-term debt	(9.1)	(5.9)
Net proceeds from private placement of common stock	240.7	0.0
Dividends paid	(12.6)	(10.5)
Proceeds from stock options exercised	0.0	0.2
Shares withheld to satisfy employee tax obligations	(1.6)	(0.5)
Other, net	(0.5)	(0.6)
Net cash provided by (used in) financing activities	102.9	(25.9)
Effect of exchange rate changes on cash and cash equivalents	0.8	2.4
Net change in cash and cash equivalents	203.6	34.0
Cash and cash equivalents, beginning of the year	46.1	21.0
Cash and cash equivalents, end of period	249.7	55.0
Less: cash and cash equivalents included in current assets held for sale	0.0	(10.1)
Cash and cash equivalents of continuing operations, end of period	249.7	44.9
Supplemental cash flow information:
Interest paid, net of amounts capitalized	26.5	26.7
Income taxes paid, net of refunds	$ 14.0	$ 13.1

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Accounting Policies and Basis of Presentation

6 Months Ended

Mar. 31, 2023

Accounting Policies [Abstract]

Accounting Policies and Basis of Presentation

Accounting Policies and Basis of Presentation:

Compass Minerals International, Inc. (“CMI”), through its subsidiaries (collectively, the “Company”), is a leading global provider of essential minerals focused on safely delivering where and when it matters to help solve nature’s challenges for customers and communities. The Company’s salt products help keep roadways safe during winter weather and are used in numerous other consumer, industrial, chemical and agricultural applications. Its plant nutrition business is the leading North American producer of sulfate of potash (“SOP”), which is used in the production of specialty fertilizers for high-value crops and turf and helps improve the quality and yield of crops, while supporting sustainable agriculture. The Company’s principal products are salt, consisting of sodium chloride and magnesium chloride, and SOP. Additionally, the Company is pursuing development of a sustainable lithium brine resource to support the North American battery market and is a minority owner of Fortress North America, LLC (“Fortress”), a next-generation fire retardant company (See Note 7, for a discussion of the subsequent acquisition of the remaining Fortress ownership interests). The Company’s production sites are located in the United States (“U.S.”), Canada and the United Kingdom (“U.K.”). The Company also provides records management services to businesses located in the U.K. Except where otherwise noted, references to North America include only the continental U.S. and Canada, and references to the U.K. include only England, Scotland and Wales. References to “Compass Minerals,” “our,” “us” and “we” refer to CMI and its consolidated subsidiaries.

CMI is a holding company with no significant operations other than those of its wholly-owned subsidiaries. The consolidated financial statements include the accounts of CMI and its wholly-owned domestic and foreign subsidiaries. All significant intercompany balances and transactions have been eliminated in consolidation.

The accompanying unaudited consolidated financial statements have been prepared in accordance with U.S. generally accepted accounting principles (“U.S. GAAP”) for interim financial information and with the instructions to Form 10-Q and Article 10 of Regulation S-X. Accordingly, they do not include all of the information and footnotes required by U.S. GAAP for complete consolidated financial statements. These unaudited consolidated financial statements should be read in conjunction with the consolidated financial statements of the Company for the annual period ended September 30, 2022, as filed with the Securities and Exchange Commission (the “SEC”) in its Annual Report on Form 10-K on December 14, 2022. In the opinion of management, all adjustments, consisting of normal recurring adjustments considered necessary for a fair presentation, have been included.

The Company experiences a substantial amount of seasonality in its sales, including its deicing salt product sales. As a result, Salt segment sales and operating income are generally higher in the first and second fiscal quarters (ending December 31 and March 31) and lower during the third and fourth fiscal quarters (ending June 30 and September 30) of each year. In particular, sales of highway and consumer deicing salt and magnesium chloride products vary based on the severity of the winter conditions in areas where the products are used. Following industry practice in North America and the U.K., the Company seeks to stockpile sufficient quantities of deicing salt throughout the first, third and fourth fiscal quarters (ending December 31, June 30 and September 30) to meet the estimated requirements for the winter season. Production of deicing salt can also vary based on the severity or mildness of the preceding winter season. Due to the seasonal nature of the deicing product lines, operating results for the interim periods are not necessarily indicative of the results that may be expected for the full fiscal year. The Company’s plant nutrition business is also seasonal. As a result, the Company and its customers generally build inventories during the plant nutrition business’ low demand periods of the year (which are typically winter and summer, but can vary due to weather and other factors) to ensure timely product availability during the peak sales seasons (which are typically spring and autumn, but can also vary due to weather and other factors).

Significant Accounting Policies

The Company’s significant accounting policies are detailed in “Note 2 – Summary of Significant Accounting Policies” within Part II, Item 8 of its Annual Report on Form 10-K for the annual period ended September 30, 2022. The Company reports its financial results from discontinued operations and continuing operations separately to recognize the financial impact of disposal transactions apart from ongoing operations. Discontinued operations reporting occurs when a component or a group of components of an entity has been disposed or classified as held for sale and represents a strategic shift that has a major effect on the entity’s operations and financial results. In the Company’s Consolidated Statements of Cash Flows, the cash flows from discontinued operations are not separately classified. Unless otherwise indicated, amounts provided in these Notes pertain to continuing operations. See Note 2 for information on discontinued operations and Note 11 for information on the Company’s reportable segments.

Recent Accounting Pronouncements

In October 2021, the Financial Accounting Standards Board issued Accounting Standards Update (“ASU”) 2021-08, “Business Combinations (Topic 805): Accounting for Contract Assets and Contract Liabilities from Contracts with Customers.” ASU 2021-08 requires the company acquiring contract assets and contract liabilities obtained in a business combination to recognize and measure them in accordance with Accounting Standards Codification 606, “Revenue from Contracts with Customers”. Following the acquisition date, the company acquiring the business should record related revenue as if it had originated the contracts. Before the update, contract assets and contract liabilities from acquired contracts were recognized by the acquiring company at fair value on the acquisition date. The amendments are effective for fiscal years beginning after December 15, 2022, including interim periods within those fiscal years. Early adoption is permitted, including in interim periods, for any financial statements that have not yet been issued. The Company early adopted these requirements, effective on January 1, 2023, with no material impact to its consolidated financial statements.

Strategic Evaluation and Plan to Sell Businesses

Following an evaluation of the strategic fit of certain of the Company’s businesses and subsequent restructuring of its former South American Plant Nutrition segment to enable separate sales processes for its chemicals and specialty plant nutrition businesses and equity investment in Fermavi Eletroquímica Ltda. (“Fermavi”), in fiscal 2021 the Company’s Board of Directors approved the plan to sell each of these businesses and the North America micronutrient business (the “Specialty Businesses”) with a goal of reducing the Company’s leverage and enabling increased focus on optimizing the Company’s core businesses.

The Company concluded that the sale of the Specialty Businesses represented a strategic shift for the Company that would have a material effect on its operations and financial results. Consequently, the Specialty businesses were reclassified as discontinued operations on the Consolidated Statements of Operations. See Note 2 for further discussion of the sales of these businesses.

Unless otherwise indicated, amounts provided in these Notes pertain to continuing operations.

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Discontinued Operations

6 Months Ended

Mar. 31, 2023

Discontinued Operations and Disposal Groups [Abstract]

Discontinued Operations

Discontinued Operations:

During fiscal 2021 the Company sold its South America specialty plant nutrition business and equity investment in Fermavi and its North America micronutrient business. In connection with the sale of its South America specialty plant nutrition business the Company received net cash of approximately $318.4 million with an additional earnout payment of up to R$88 million Brazilian reais. On April 7, 2022, the Company received the maximum earnout possible under the terms of the sale, or $18.5 million based on exchange rates at the time of receipt.

Also in fiscal 2021, the Company completed the sale of its North America micronutrient business for approximately $56.7 million and its investment in Fermavi for R$45 million Brazilian reais (including R$30 million Brazilian reais of deferred purchase price). The Company received gross proceeds of approximately $2.9 million and recorded a discounted deferred proceeds receivable of approximately $4.8 million (based on exchange rates at the time of closing). As of March 31, 2023 approximately R$22.5 million Brazilian reais of deferred proceeds remains outstanding.

On April 20, 2022, the Company completed the sale of its South America chemicals business to a subsidiary of Cape Acquisitions LLC. Upon closing of the all-cash sale, the Company received gross proceeds of approximately $51.5 million based on exchange rates at the time of receipt, including a post-closing adjustment and compensation of $6.4 million for cash on hand that transferred to the buyer. The Company also paid fees of $2.4 million related to this sale. The Company recognized a loss recovery of $1.6 million during the three months ended June 30, 2022, an incremental loss from the sale of $23.1 million during the nine months ended June 30, 2022 and released $49.5 million from accumulated currency translation adjustment (“CTA”). The sale included all of the Company’s remaining operations in Brazil, concluding its previously announced plan to exit the South American market.

In measuring the assets and liabilities held for sale at fair value less estimated costs to sell, the Company completed an impairment analysis when its Board of Directors committed to a plan to sell the Specialty Businesses and the Company updated the analysis each quarter until each of the Specialty Businesses were sold.

The information below sets forth selected financial information related to the operating results of the Specialty Businesses classified as discontinued operations. The Specialty Businesses’ revenue and expenses have been reclassified to net earnings from discontinued operations in prior periods. The Consolidated Statements of Operations present the revenue and expenses that were reclassified from the specified line items to discontinued operations.

The following table represents summarized Consolidated Statements of Operations information of discontinued operations (in millions):

	Three Months Ended March 31,			Six Months Ended March 31,
		2022			2022
Sales		$	24.3		$	46.7
Shipping and handling cost		1.3			2.5
Product cost		14.4			25.3
Gross profit		8.6			18.9
Selling, general and administrative expenses		1.4			3.0
Operating earnings		7.2			15.9
Interest expense		0.1			0.1
Gain on foreign exchange		(20.4)			(17.3)
Net loss on adjustment to fair value less estimated costs to sell		16.3			24.7
Other income, net		(0.3)			(0.5)
Earnings from discontinued operations before income taxes		11.5			8.9
Income tax benefit		(5.4)			(2.5)
Net earnings from discontinued operations		$	16.9		$	11.4

The significant components included in the Company’s Consolidated Statements of Cash Flows for discontinued operations are as follows (in millions):

	Six Months Ended March 31,
	2022
Loss on impairment of long-lived assets	$	24.7
Capital expenditures	(1.2)

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Revenues

6 Months Ended

Mar. 31, 2023

Revenue from Contract with Customer [Abstract]

Revenues

Revenues:

Nature of Products and Services

The Company’s Salt segment products include salt and magnesium chloride for use in road deicing and dust control, food processing, water softening, and agricultural and industrial applications. The Company’s Plant Nutrition segment produces and markets SOP in various grades worldwide to distributors and retailers of crop inputs, as well as growers and for industrial uses. In the U.K., the Company operates a records management business utilizing excavated areas of its Winsford salt mine with one other location in London, England.

Identifying the Contract

The Company accounts for a customer contract when there is approval and commitment from both parties, the rights of the parties and payment terms are identified, the contract has commercial substance and collectability of consideration is probable.

Identifying the Performance Obligations

At contract inception, the Company assesses the goods and services it has promised to its customers and identifies a performance obligation for each promise to transfer to the customer a distinct good or service (or bundle of goods or services). Determining whether products and services are considered distinct performance obligations that should be accounted for separately or aggregated together may require significant judgment.

Identifying and Allocating the Transaction Price

The Company’s revenues are measured based on consideration specified in the customer contract, net of any sales incentives and amounts collected on behalf of third parties such as sales taxes. In certain cases, the Company’s customer contracts may include promises to transfer multiple products and services to a customer. For multiple-element arrangements, the Company generally allocates the transaction price to each performance obligation in proportion to its stand-alone selling price.

When Performance Obligations Are Satisfied

The vast majority of the Company’s revenues are recognized at a point in time when the performance obligations are satisfied based upon transfer of control of the product or service to a customer. To determine when the control of goods is transferred, the Company typically assesses, among other things, the shipping terms of the contract, as shipping is an indicator of transfer of control. Some of the Company’s products are sold when the control of the goods transfers to the customer at the time of shipment. There are also instances when the Company provides shipping services to deliver its products. Shipping and handling costs that occur before the customer obtains control of the goods are deemed to be fulfillment activities and are accounted for as fulfillment costs. The Company has made an accounting policy election to recognize any shipping and handling costs that are incurred after the customer obtains control of the goods as fulfillment costs which are accrued at the time of revenue recognition.

Significant Payment Terms

The customer contract states the final terms of the sale, including the description, quantity and price of each product or service purchased. Payment is typically due in full within 30 days of delivery. The Company does not adjust the consideration for the effects of a significant financing component if the Company expects, at contract inception, that the period between when the good or service is transferred to the customer and when the customer pays for that good or service will be one year or less.

Refunds, Returns and Warranties

The Company’s products are generally not sold with a right of return and the Company does not generally provide credits or incentives, which may be required to be accounted for as variable consideration when estimating the amount of revenue to be recognized. The Company uses historical experience to estimate accruals for refunds due to manufacturing or other defects.

See Note 11 for disaggregation of sales by segment, type and geographical region.

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Inventories

6 Months Ended

Mar. 31, 2023

Inventory Disclosure [Abstract]

Inventories

Inventories:

Inventories consist of the following (in millions):

	March 31, 2023		September 30, 2022
Finished goods	$	203.8	$	251.6
Raw materials and supplies	57.9		52.8
Total inventories	$	261.7	$	304.4

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Property, Plant and Equipment, Net

6 Months Ended

Mar. 31, 2023

Property, Plant and Equipment [Abstract]

Property, Plant and Equipment, Net

Property, Plant and Equipment, Net:

Property, plant and equipment, net, consists of the following (in millions):

	March 31, 2023		September 30, 2022
Land, buildings and structures, and leasehold improvements	$	545.4	$	534.8
Machinery and equipment	1,071.1		1,026.3
Office furniture and equipment	58.6		56.8
Mineral interests	169.1		167.1
Construction in progress	57.2		64.3
	1,901.4		1,849.3
Less: accumulated depreciation and depletion	(1,118.8)		(1,072.7)
Property, plant and equipment, net	$	782.6	$	776.6

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Goodwill and Intangible Assets, Net

6 Months Ended

Mar. 31, 2023

Goodwill and Intangible Assets Disclosure [Abstract]

Goodwill and Intangible Assets, Net

Goodwill and Intangible Assets, Net:

Amounts related to the Company’s amortization of intangible assets are as follows (in millions):

	Three Months Ended March 31,				Six Months Ended March 31,
	2023		2022		2023		2022
Aggregate amortization expense	$	0.4	$	0.4	$	0.8	$	0.8

Amounts related to the Company’s goodwill are as follows (in millions):

	March 31, 2023		September 30, 2022
Plant Nutrition	$	51.0	$	50.9
Other	5.9		5.5
Total	$	56.9	$	56.4

The change in goodwill between September 30, 2022, and March 31, 2023 was due to the impact from translating foreign-denominated amounts to U.S. dollars. As of March 31, 2023, there were no indicators necessitating an interim impairment test of the Company’s reporting units based on the Company’s review of operating performance, among other factors, for the relevant reporting units.

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Equity Method Investments

6 Months Ended

Mar. 31, 2023

Equity Method Investments and Joint Ventures [Abstract]

Equity Method Investments

Equity Method Investments:

The Company uses the equity method of accounting for equity securities when it has significant influence or when it has more than a minor ownership interest or more than minor influence over an investee’s operations but does not have a controlling financial interest. Initial investments are recorded at cost (including certain transaction costs) and are adjusted by the Company’s share of the investees’ undistributed earnings and losses. The Company may recognize its share of an investee’s earnings on a lag if an investee’s financial results are not available in a timely manner.

For certain of the Company's equity method investments, such as investments where the capital structure of the equity investment results in different liquidation rights and priorities than what is reflected by the underlying percentage ownership interests, the Company's proportionate share of net earnings is accounted for using the Hypothetical Liquidation at Book Value ("HLBV") methodology available under the equity method of accounting. When applying HLBV, the Company determines the amount that would be received if the investee were to liquidate all of its assets and distribute the resulting cash to the investors based on contractually defined liquidation priorities, assuming the net assets were liquidated at their net book value.

The Company evaluates its equity method investments for impairment whenever events or changes in circumstances indicate that the carrying amounts of such investments may not be recoverable.

On November 2, 2021, the Company announced an investment in Fortress, a next-generation fire retardant business dedicated to developing and producing a portfolio of magnesium chloride-based fire retardant products to help combat wildfires. As of March 31, 2023, the Company has invested $50 million in Fortress in exchange for an ownership interest of approximately 45%. Under the HLBV methodology available under the equity method of accounting, the Company reflects its share of the income or loss of Fortress in its results each period on a one quarter reporting lag. The Company recorded $1.0 million and $1.5 million for its share of Fortress’ net losses in the three and six months ended March 31, 2023, respectively, and $1.2 million and $1.3 million for its share of Fortress’ net losses in the three and six months ended March 31, 2022, respectively.

The carrying value of the Company’s equity investment in Fortress is in excess of its share of Fortress’s net book value by approximately $27 million as of March 31, 2023. The basis difference primarily represents incremental value attributable to intangible assets and goodwill that has not been recognized in the financial statements of Fortress. The Company has liquidation preference under the terms of Fortress’ LLC agreement. Additionally, the Company has the right to purchase units from other Fortress unit holders and the right of first refusal to purchase all or any portion of any available Fortress units, both subject to certain conditions.

The balance of the Company’s net investment in Fortress of $44.3 million and $45.8 million as of March 31, 2023 and September 30, 2022, respectively is recorded in equity method investments in the Consolidated Balance Sheets. The Company also has other immaterial equity investments valued at $0.0 million and $0.8 million as of March 31, 2023 and September 30, 2022, respectively, for which it has recorded $0.4 million and $0.8 million for its share of losses in the three and six months ended March 31, 2023, respectively, and $0.5 million and $0.8 million for its share of losses in the three and six months ended March 31, 2022, respectively.

On May 5, 2023, the Company acquired the remaining 55% interest in Fortress consisting of an initial cash payment of approximately $26 million, approximately $28 million to be paid in cash and/or Compass Minerals common stock upon the achievement of certain performance measures, and a cash earn-out based on volumes of certain Fortress fire retardant products sold over a 10-year period. Building upon the previous 45% minority ownership stake in Fortress, the transaction provides the Company full ownership of all Fortress assets, contracts, and intellectual property.

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Income Taxes

6 Months Ended

Mar. 31, 2023

Income Tax Disclosure [Abstract]

Income Taxes

Income Taxes:

The Company’s effective income tax rate differs from the U.S. statutory federal income tax rate primarily due to U.S. statutory depletion, state income taxes (net of federal tax benefit), nondeductible executive compensation over $1 million, foreign income, mining and withholding taxes, base erosion and anti-abuse tax, and valuation allowances recorded on deferred tax assets. For the six months ended March 31, 2022, there were also interest expense recognition differences for book and tax purposes.

Management assesses the available positive and negative evidence to estimate whether sufficient future taxable income will be generated to permit use of the existing deferred tax assets. A significant piece of objective negative evidence evaluated was the cumulative loss incurred in the U.S. over the three-year period ended March 31, 2023. Such objective evidence limits the ability to consider other subjective evidence, such as the Company’s projections for future income. On the basis of this evaluation, during the six months ended March 31, 2023, an additional valuation allowance of $15.8 million has been recorded to recognize only the portion of the U.S. deferred tax assets that is more likely than not to be realized. The amount of the deferred tax assets considered realizable, however, could be adjusted if estimates of future taxable income during the carryforward period are increased or reduced or if objective negative evidence in the form of cumulative losses is no longer present and additional weight is given to subjective evidence such as the Company’s projections for income.

As of March 31, 2023, and September 30, 2022, the Company had $82.1 million and $94.1 million, respectively of gross foreign federal NOL carryforwards that have no expiration date and $3.8 million and $3.2 million, respectively of net operating tax-effected state NOL carryforwards which expire beginning in 2035.

Canadian provincial tax authorities have challenged tax positions claimed by one of the Company’s Canadian subsidiaries and have issued tax reassessments for fiscal years 2002-2017. The reassessments are a result of ongoing audits and total $173.1 million, including interest, through March 31, 2023. The Company disputes these reassessments and will continue to work with the appropriate authorities in Canada to resolve the dispute. There is a reasonable possibility that the ultimate resolution of this dispute, and any related disputes for other open tax years, may be materially higher or lower than the amounts the Company has reserved for such disputes. In connection with this dispute, local regulations require the Company to post security with the tax authority until the dispute is resolved. The Company has posted collateral in the form of a $143.6 million performance bond and

has paid $36.7 million to the Canadian tax authorities (most of which is recorded in other assets in the Consolidated Balance Sheets at March 31, 2023, and September 30, 2022), which is necessary to proceed with future appeals or litigation.

The Company expects that it will be required by local regulations to provide security for additional interest on the above unresolved disputed amounts and for any future reassessments issued by these Canadian tax authorities in the form of cash, letters of credit, performance bonds, asset liens or other arrangements agreeable with the tax authorities until the disputes are resolved.

The Company expects that the ultimate outcome of these matters will not have a material impact on its results of operations or financial condition. However, the Company can provide no assurance as to the ultimate outcome of these matters, and the impact could be material if they are not resolved in the Company’s favor. As of March 31, 2023, the Company believes it has adequately reserved for these reassessments.

Additionally, the Company has other uncertain tax positions as well as assessments and disputed positions with taxing authorities in its various jurisdictions, which are consistent with those matters disclosed in the Company’s Annual Report on Form 10-K for the annual period ended September 30, 2022.

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Long-Term Debt

6 Months Ended

Mar. 31, 2023

Debt Disclosure [Abstract]

Long-Term Debt

Long-Term Debt:

Long-term debt consists of the following (in millions):

	March 31, 2023		September 30, 2022
4.875% Senior Notes due July 2024	$	250.0	$	250.0
Term Loan due January 2025	16.9		16.9
Revolving Credit Facility due January 2025	—		151.5
6.75% Senior Notes due December 2027	500.0		500.0
AR Securitization Facility expires June 2025	65.9		37.5
	832.8		955.9
Less unamortized debt issuance costs	(7.1)		(8.3)
Total debt	825.7		947.6
Less current portion	—		—
Long-term debt	$	825.7	$	947.6

As of March 31, 2023, the term loan and revolving credit facility under the Company’s credit agreement entered into on November 26, 2019 (as amended, the “2019 Credit Agreement”) were secured by substantially all existing and future U.S. assets of the Company, the Goderich mine in Ontario, Canada and capital stock of certain subsidiaries. As of March 31, 2023, the weighted average interest rate on all borrowings outstanding under the term loan under the Credit Agreement was approximately 6.9%.

The Company is in compliance as of March 31, 2023 with its debt covenants under the Credit Agreement and its AR Securitization Facility. Pursuant to the terms of the second amendment to the Credit Agreement the maximum allowed consolidated total net leverage ratio (as defined and calculated under the terms of the Credit Agreement and discussed further below) was 5.0x for the quarter ended March 31, 2023, which steps down to 4.75x in the quarter ending March 31, 2024, and to 4.5x for the fiscal quarter ended June 30, 2024 and thereafter. The consolidated total net leverage ratio represents the ratio of (a) consolidated total net debt to (b) consolidated adjusted earnings before interest, taxes, depreciation and amortization (“EBITDA”). Consolidated total net debt includes the aggregate principal amount of total debt, net of unrestricted cash not to exceed $50.0 million.

In November 2022, the Company entered into the third amendment to the 2019 Credit Agreement, principally to affect a transition from the London Inter-Bank Offered Rate to the Secured Overnight Financing Rate pricing benchmark provisions.

During the quarter ended December 31, 2022, the Company paid off the outstanding revolving credit facility balance utilizing proceeds from a private placement of common stock. Refer to Note 12 for additional details of the private placement transaction.

In January 2023, certain of the Company’s U.S. subsidiaries entered into the second amendment to the AR Securitization Facility with PNC Bank, which temporarily eases the restrictions of certain covenants contained in the agreement through March 2023. The amendment made certain adjustments to the financial tests including: (i) the default ratio and (ii) the delinquency ratio to make compliance with such tests more likely.

On May 5, 2023, the Company entered into an agreement to amend and restate the 2019 Credit Agreement (as in effect prior to such restatement, the “Existing Credit Agreement”) with a new $575 million senior secured credit agreement due May 5, 2028 (as amended, the “2023 Credit Agreement”), comprised of a $375 million revolving credit facility and a $200 million term loan. The term loan is payable in quarterly installments of interest and principal beginning September 30, 2023. The 2023 Credit Agreement increases the Applicable Margins by 25 basis points over those defined in the Existing Credit Agreement and adds an additional level at a consolidated total leverage ratio of greater than 4:00 to 1.00. Consolidated total net debt includes the aggregate principal amount of total debt, net of unrestricted cash, which was increased from $50.0 million to $75 million, in the 2023 Credit Agreement. Proceeds from the 2023 Credit Agreement will be used by the Company to redeem its $250 million 4.875% Senior Notes on May 10, 2023 and pay off the Existing Credit Agreement term loan balance of $16.9 million.

The 2023 Credit Agreement, among other things, amends and restates the Existing Credit Agreement to (i) increase the Revolving Commitments (as defined in the Existing Credit Agreement) from $300 million to $375 million and extend the maturity date of the Revolving Commitments to May 5, 2028, (ii) refinance the Term Loans (as defined in the Existing Credit Agreement) with a new tranche of term loans in an aggregate principal amount equal to $200 million having a maturity date of May 5, 2028, and (iii) amend certain other terms of the Existing Credit Agreement, including, but not limited to, (a) expressly permit “run rate” cost savings in “Consolidated Adjusted EBITDA” (as defined in the Existing Credit Agreement) and (b) revise select covenants in the Existing Credit Agreement to, among other things, allow for Lithium Transactions (as defined below).

The 2023 Credit Agreement will permit, on the terms and conditions set forth therein, the entry into, and consummation of, lithium development joint ventures, projects or similar arrangements by any Lithium Subsidiary (as defined below), and any related funding transactions in connection therewith (collectively, the “Lithium Transactions”). A “Lithium Subsidiary” shall mean (a) Compass Minerals Lithium Corp of America Inc., a Delaware corporation, or any successor thereto and (b) (x) any newly-formed domestic subsidiary that is a wholly-owned Subsidiary of the Company (each of which will become a Subsidiary Guarantor (as defined in the Existing Credit Agreement)) and/or (y) any newly-formed domestic subsidiary that is not a wholly-owned subsidiary of the Company (each of which may, but shall not be required to become, at the option of the Company, a Subsidiary Guarantor), in each case formed in order to effectuate the Lithium Transactions.

The 2023 Credit Agreement is secured by substantially all existing and future U.S. assets of the Company, the Goderich mine in Ontario, Canada and capital stock of certain subsidiaries. The Term Loan requires the Company to maintain certain financial ratios, including a minimum interest coverage ratio and a maximum total net leverage ratio.

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Commitments and Contingencies

6 Months Ended

Mar. 31, 2023

Commitments and Contingencies Disclosure [Abstract]

Commitments and Contingencies

Commitments and Contingencies:

As previously disclosed, the Company was the subject of an investigation by the Division of Enforcement of the SEC regarding the Company’s disclosures primarily concerning the operation of the Goderich mine, the former South American businesses, and related accounting and internal control matters including Salt interim inventory valuation methodology issues that were disclosed in the Company’s Form 10-K/A for the year ended December 31, 2020, and Form 10-Q/A for the quarter ended March 31, 2021, each filed with the SEC on September 3, 2021.

On September 23, 2022, the Company reached a settlement with the SEC, concluding and resolving the SEC investigation in its entirety. Under the terms of the settlement, the Company, without admitting or denying the findings in the administrative order issued by the SEC, agreed to pay a civil penalty of $12 million and to cease and desist from violations of specified provisions of the federal securities laws and rules promulgated thereunder, and to retain an independent compliance consultant for a period of approximately one year to review certain accounting practices and procedures. As set forth in the administrative order, the $12 million civil penalty is to be paid in installments: $2 million, which was paid on September 29, 2022, and $10 million to be paid no later than September 30, 2023. The Company previously recorded an accrual for the full amount of the penalty in the

third quarter of fiscal 2022, which is reflected in accrued expenses and other current liabilities on the Company’s Consolidated Balance Sheets.

The Company is also involved in legal and administrative proceedings and claims of various types from the ordinary course of the Company’s business.

Management cannot predict the outcome of legal claims and proceedings with certainty. Nevertheless, management believes that the outcome of legal proceedings and claims, which are pending or known to be threatened, even if determined adversely, will not, individually or in the aggregate, have a material adverse effect on the Company’s results of operations, cash flows or financial position, except as otherwise described in Note 8 and this Note 10.

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Operating Segments

6 Months Ended

Mar. 31, 2023

Segment Reporting [Abstract]

Operating Segments

Operating Segments:

The Company’s reportable segments are strategic business units that offer different products and services, and each business requires different technology and marketing strategies. In connection with the executed business disposals discussed in Note 1 and Note 2, the Company has identified two reportable segments. The Specialty Businesses that comprised the Company’s former Plant Nutrition South America reportable segment and the North America micronutrient product business previously reported within the former Plant Nutrition North America reportable segment were classified as discontinued operations for all periods presented in its consolidated financial statements in this Quarterly Report on Form 10-Q.

For the three and six months ended March 31, 2023 and 2022, the Company has presented two reportable segments in its Consolidated Financial Statements: Salt and Plant Nutrition. The Salt segment produces and markets salt, consisting of sodium chloride and magnesium chloride, for use in road deicing for winter roadway safety and for dust control, food processing, water softening and other consumer, agricultural and industrial applications. The Plant Nutrition segment produces and markets various grades of SOP.

Segment information is as follows (in millions):

Three Months Ended March 31, 2023	Salt		Plant Nutrition		Corporate & Other(a)(b)(c)		Total
Sales to external customers	$	360.5	$	47.7	$	2.9	$	411.1
Intersegment sales	—		1.4		(1.4)		—
Shipping and handling cost	124.0		6.1		—		130.1
Operating earnings (loss)(b)(c)	73.1		(0.7)		(24.5)		47.9
Depreciation, depletion and amortization	14.8		8.1		1.6		24.5
Total assets (as of end of period)	924.1		472.7		387.9		1,784.7

Three Months Ended March 31, 2022	Salt		Plant Nutrition		Corporate & Other(a)(b)		Total
Sales to external customers	$	391.3	$	54.3	$	2.9	$	448.5
Intersegment sales	—		0.7		(0.7)		—
Shipping and handling cost	153.4		6.7		—		160.1
Operating earnings (loss)(b)	49.3		4.4		(33.7)		20.0
Depreciation, depletion and amortization	16.2		8.8		2.9		27.9
Total assets (as of end of period)	925.4		444.4		266.4		1,636.2

Six Months Ended March 31, 2023	Salt		Plant Nutrition		Corporate & Other(a)(b)(c)		Total
Sales to external customers	$	668.6	$	89.3	$	5.6	$	763.5
Intersegment sales	—		4.3		(4.3)		—
Shipping and handling cost	226.7		10.8		—		237.5
Operating earnings (loss)(b)(c)	120.2		10.3		(54.7)		75.8
Depreciation, depletion and amortization	28.7		16.4		3.3		48.4

Six Months Ended March 31, 2022	Salt		Plant Nutrition		Corporate & Other(a)(b)		Total
Sales to external customers	$	665.2	$	108.9	$	5.9	$	780.0
Intersegment sales	—		3.1		(3.1)		—
Shipping and handling cost	241.8		14.0		—		255.8
Operating earnings (loss)(b)	88.7		13.9		(62.2)		40.4
Depreciation, depletion and amortization	32.4		17.6		6.2		56.2

Disaggregated revenue by product type is as follows (in millions):

Three Months Ended March 31, 2023	Salt		Plant Nutrition		Corporate & Other(a)		Total
Highway Deicing Salt	$	273.7	$	—	$	—	$	273.7
Consumer & Industrial Salt	86.8		—		—		86.8
SOP	—		49.1		—		49.1
Eliminations & Other	—		(1.4)		2.9		1.5
Sales to external customers	$	360.5	$	47.7	$	2.9	$	411.1

Three Months Ended March 31, 2022	Salt		Plant Nutrition		Corporate & Other(a)		Total
Highway Deicing Salt	$	300.1	$	—	$	—	$	300.1
Consumer & Industrial Salt	91.2		—		—		91.2
SOP	—		55.0		—		55.0
Eliminations & Other	—		(0.7)		2.9		2.2
Sales to external customers	$	391.3	$	54.3	$	2.9	$	448.5

Six Months Ended March 31, 2023	Salt		Plant Nutrition		Corporate & Other(a)		Total
Highway Deicing Salt	$	464.0	$	—	$	—	$	464.0
Consumer & Industrial Salt	204.6		—		—		204.6
SOP	—		93.6		—		93.6
Eliminations & Other	—		(4.3)		5.6		1.3
Sales to external customers	$	668.6	$	89.3	$	5.6	$	763.5

Six Months Ended March 31, 2022	Salt		Plant Nutrition		Corporate & Other(a)		Total
Highway Deicing Salt	$	463.8	$	—	$	—	$	463.8
Consumer & Industrial Salt	201.4		—		—		201.4
SOP	—		112.0		—		112.0
Eliminations & Other	—		(3.1)		5.9		2.8
Sales to external customers	$	665.2	$	108.9	$	5.9	$	780.0

(a)Corporate and Other includes corporate entities, records management operations, equity method investments, lithium development costs and other incidental operations and eliminations. Operating earnings (loss) for corporate and other includes indirect corporate overhead, including costs for general corporate governance and oversight, lithium-related expenses, as well as costs for the human resources, information technology, legal and finance functions.

(b)Corporate operating results for the three and six months ended March 31, 2023 include net reimbursements related to the settled SEC investigation of $0.4 million and $0.1 million, respectively. Corporate operating results for the three and six months ended March 31, 2022 include executive transition costs of $0.5 million and $3.8 million, respectively, and a contingent loss accrual and costs related to the SEC investigation of $13.6 million and $16.7 million, respectively. Refer to Note 10 for more information regarding the SEC investigation.

(c)In April 2023, the Company took initial steps to align its cost structure to its current business needs. These initiatives resulted in restructuring charges of $3.3 million, which impacted Corporate operating results for the three and six months ended March 31, 2023.

The Company’s revenue by geographic area is as follows (in millions):

	Three Months Ended March 31,				Six Months Ended March 31,
Revenue	2023		2022		2023		2022
United States(a)	$	283.1	$	327.8	$	531.3	$	549.1
Canada	101.0		104.5		188.6		193.9
United Kingdom	23.2		15.6		37.3		35.4
Other	3.8		0.6		6.3		1.6
Total revenue	$	411.1	$	448.5	$	763.5	$	780.0

(a)United States sales exclude product sold to foreign customers at U.S. ports.

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Stockholders' Equity and Equity Instruments

6 Months Ended

Mar. 31, 2023

Equity [Abstract]

Stockholders' Equity and Equity Instruments

Stockholders’ Equity and Equity Instruments:

In May 2020, the Company’s stockholders approved the 2020 Incentive Award Plan (as amended, the “2020 Plan”), which authorized the issuance of 2,977,933 shares of Company common stock. In February 2022, the Company’s stockholders approved an amendment to the 2020 Plan authorizing an additional 750,000 shares of Company stock. Since the date the 2020 Plan was approved, the Company ceased issuing equity awards under the 2015 Incentive Award Plan (as amended, the “2015 Plan”). Since the approval of the 2015 Plan in May 2015, the Company ceased issuing equity awards under the 2005 Incentive Award Plan (as amended, the “2005 Plan”). The 2005 Plan, the 2015 Plan and the 2020 Plan allow for grants of equity awards to executive officers, other employees and directors, including restricted stock units (“RSUs”), performance stock units (“PSUs”), stock options and deferred stock units.

Koch Equity Investment

On September 14, 2022, the Company entered into a Stock Purchase Agreement with Koch Minerals & Trading, LLC (“KM&T”), a subsidiary of Koch Industries, Inc. (“KII”), pursuant to which the Company agreed to issue and sell 6,830,700 shares of its common stock at a purchase price of $36.87 for aggregate net proceeds of approximately $240.7 million, net of transaction costs. On October 18, 2022, the Company closed the direct private placement with KM&T, through its affiliate KM&T Investment Holdings, LLC, resulting in their ownership of approximately 17% of the Company’s outstanding common stock. The Company expects to use approximately $200 million of the proceeds from the private placement to advance the first development phase of its sustainable lithium development project at its Ogden site. The Company used the remaining approximately $40.7 million of proceeds to reduce debt.

Options

Substantially all of the stock options granted vest ratably, in tranches, over a four-year service period. Unexercised options expire after seven years. Options do not have dividend or voting rights. Upon vesting, each option can be exercised to purchase one share of the Company’s common stock. The exercise price of options is equal to the closing stock price on the grant date.

To estimate the fair value of options on the grant date, the Company uses the Black-Scholes option valuation model. Award recipients are grouped according to expected exercise behavior. Unless better information is available to estimate the expected term of the options, the estimate is based on historical exercise experience. The risk-free rate, using U.S. Treasury yield curves in effect at the time of grant, is selected based on the expected term of each group. The Company’s historical stock price is used to estimate expected volatility.

RSUs

Typically, the RSUs granted under the 2015 Plan and the 2020 Plan vest after one to three years of service. RSUs entitle the holders to one share of common stock for each vested RSU. Unvested RSUs do not have voting rights but are entitled to receive non-forfeitable dividends (generally after a performance hurdle has been satisfied for the year of the grant) or other distributions equal to those declared on the Company’s common stock for RSUs that are earned as a result of the satisfaction of the performance hurdle. The closing stock price on the grant date is used to determine the fair value of RSUs.

PSUs

Substantially all of the PSUs outstanding under the 2015 Plan and the 2020 Plan are either total stockholder return PSUs (“TSR PSUs”) or adjusted EBITDA growth PSUs (“EBITDA Growth PSUs”). The actual number of shares of the Company’s common stock that may be earned with respect to TSR PSUs is calculated by comparing the Company’s total stockholder return to the total stockholder return for each company comprising the Company’s peer group or a total return percentage target over a two- or three-year performance period and may range from 0% to 300% of the target number of shares based upon the attainment of these performance conditions. The actual number of shares of common stock that may be earned with respect to EBITDA Growth PSUs is calculated based on the attainment of adjusted EBITDA growth during the performance period and may range from 0% to 300% of the target number of shares based upon the attainment of these performance conditions.

PSUs represent a target number of shares of the Company’s common stock that may be earned before adjustment based upon the attainment of certain performance conditions. Holders of PSUs do not have voting rights but are entitled to receive non-forfeitable dividends or other distributions equal to those declared on the Company’s common stock for PSUs that are earned, which are paid when the shares underlying the PSUs are issued.

To estimate the fair value of the TSR PSUs on the grant date for accounting purposes, the Company uses a Monte-Carlo simulation model, which simulates future stock prices of the Company as well as the Company’s peer group. This model uses historical stock prices to estimate expected volatility and the Company’s correlation to the peer group. The risk-free rate was determined using the same methodology as the option valuations as discussed above. The Company’s closing stock price on the grant date was used to estimate the fair value of the EBITDA Growth PSUs. The Company will adjust the expense of the EBITDA Growth PSUs based upon its estimate of the number of shares that will ultimately vest at each interim date during the vesting period.

During the six months ended March 31, 2023, the Company reissued the following number of shares from treasury stock: 115,123 shares related to the release of RSUs which vested and 58,287 shares related to stock payments. In fiscal 2022, the Company issued 117,390 net shares from treasury stock. The Company withheld a total of 35,731 shares with a fair value of $1.6 million related to the vesting of RSUs, PSUs, and stock payments during the six months ended March 31, 2023. The fair value of the shares was valued at the closing price at the vesting date and represent the employee tax withholding for the employee’s compensation. The Company recognized tax expense of $0.7 million from its equity compensation awards during the six months ended March 31, 2023. During the six months ended March 31, 2023 and 2022, the Company recorded $14.1 million and $9.2 million (includes $0.4 million and $1.4 million paid in cash), respectively, of compensation expense pursuant to its stock-based compensation plans. No amounts have been capitalized.

The following table summarizes stock-based compensation activity during the six months ended March 31, 2023:

	Stock Options			RSUs			PSUs(a)
	Number	Weighted-average exercise price		Number	Weighted-average fair value		Number	Weighted-average fair value
Outstanding at September 30, 2022	774,580	$	60.68	208,735	$	63.02	331,359	$	71.51
Granted	—	—		238,075	38.29		183,974	68.33
Exercised(b)	—	—		—	—		—	—
Released from restriction(b)	—	—		(122,645)	61.80		—	—
Cancelled/expired	(24,962)	62.53		(12,501)	46.86		(109,276)	66.69
Outstanding at March 31, 2023	749,618	$	60.61	311,664	$	45.26	406,057	$	71.37

(a)Until the performance period is completed, PSUs are included in the table at the target level at their grant date and at that level represent one share of common stock per PSU.

(b)Common stock issued for exercised options and for vested and earned RSUs and PSUs was issued from treasury stock.

Accumulated Other Comprehensive Loss (“AOCL”)

The Company’s comprehensive income (loss) is comprised of net earnings (loss), net amortization of the unrealized loss of the pension obligation, the change in the unrealized gain in other postretirement benefits, the change in the unrealized gain (loss) on natural gas and foreign currency cash flow hedges and CTA. The components of and changes in AOCL are as follows (in millions):

Three Months Ended March 31, 2023(a)	Gains and (Losses) on Cash Flow Hedges		Defined Benefit Pension		Other Post-Employment Benefits		Foreign Currency		Total
Beginning balance	$	(4.4)	$	(2.6)	$	1.3	$	(100.6)	$	(106.3)
Other comprehensive (loss) income before reclassifications(b)	(1.8)		—		—		2.8		1.0
Amounts reclassified from AOCL	0.7		—		—		—		0.7
Net current period other comprehensive (loss) income	(1.1)		—		—		2.8		1.7
Ending balance	$	(5.5)	$	(2.6)	$	1.3	$	(97.8)	$	(104.6)

Three Months Ended March 31, 2022(a)	Gains and (Losses) on Cash Flow Hedges		Defined Benefit Pension		Foreign Currency		Total
Beginning balance	$	1.1	$	(5.3)	$	(112.0)	$	(116.2)
Other comprehensive income before reclassifications(b)	1.6		—		10.7		12.3
Amounts reclassified from AOCL	(0.6)		0.1		—		(0.5)
Net current period other comprehensive income	1.0		0.1		10.7		11.8
Ending balance	$	2.1	$	(5.2)	$	(101.3)	$	(104.4)

Six Months Ended March 31, 2023(a)	Gains and (Losses) on Cash Flow Hedges		Defined Benefit Pension		Other Post-Employment Benefits		Foreign Currency		Total
Beginning balance	$	(1.6)	$	(2.7)	$	1.3	$	(112.3)	$	(115.3)
Other comprehensive (loss) income before reclassifications(b)	(4.2)		—		—		14.5		10.3
Amounts reclassified from AOCL	0.3		0.1		—		—		0.4
Net current period other comprehensive (loss) income	(3.9)		0.1		—		14.5		10.7
Ending balance	$	(5.5)	$	(2.6)	$	1.3	$	(97.8)	$	(104.6)

Six Months Ended March 31, 2022(a)	Gains and (Losses) on Cash Flow Hedges		Defined Benefit Pension		Foreign Currency		Total
Beginning balance	$	3.1	$	(5.4)	$	(108.2)	$	(110.5)
Other comprehensive income before reclassifications(b)	0.7		—		6.9		7.6
Amounts reclassified from AOCL	(1.7)		0.2		—		(1.5)
Net current period other comprehensive (loss) income	(1.0)		0.2		6.9		6.1
Ending balance	$	2.1	$	(5.2)	$	(101.3)	$	(104.4)

(a)With the exception of the CTA, for which no tax effect is recorded, the changes in the components of AOCL presented in the tables above are reflected net of applicable income taxes.

(b)The Company recorded foreign exchange (loss) of $(0.1) million and $(1.4) million in the three and six months ended March 31, 2023, respectively, and $(1.9) million and $(0.7) million in the three and six months ended March 31, 2022, respectively, in AOCL related to intercompany notes which were deemed to be of a long-term investment nature.

The amounts reclassified from AOCL to expense (income) for the three and six months ended March 31, 2023 and 2022, are shown below (in millions):

	Amount Reclassified from AOCL
	Three Months Ended March 31,				Six Months Ended March 31,				Line Item Impacted in the Consolidated Statements of Operations
	2023		2022		2023		2022
Loss (Gain) on cash flow hedges:
Natural gas instruments	$	1.0	$	(0.9)	$	0.5	$	(2.3)	Product cost
Income tax expense	(0.3)		0.3		(0.2)		0.6
Reclassifications, net of income taxes	0.7		(0.6)		0.3		(1.7)
Amortization of defined benefit pension:
Amortization of loss	—		0.1		0.1		0.2		Product cost
Income tax benefit	—		—		—		—
Reclassifications, net of income taxes	—		0.1		0.1		0.2
Amortization of other post-employment benefits:
Amortization of loss	—		—		—		—		Product cost
Income tax benefit	—		—		—		—
Reclassifications, net of income taxes	—		—		—		—
Total reclassifications, net of income taxes	$	0.7	$	(0.5)	$	0.4	$	(1.5)

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Derivative Financial Instruments

6 Months Ended

Mar. 31, 2023

Derivative Instruments and Hedging Activities Disclosure [Abstract]

Derivative Financial Instruments

Derivative Financial Instruments:

The Company is subject to various types of market risks, including interest rate risk, foreign currency exchange rate transaction and translation risk and commodity pricing risk. Management may take actions to mitigate the exposure to these types of risks, including entering into forward purchase contracts and other financial instruments. The Company manages a portion of its commodity pricing risks and foreign currency exchange rate risks by using derivative instruments. From time to time, the Company may enter into foreign exchange contracts to mitigate foreign exchange risk. The Company does not seek to engage in trading activities or take speculative positions with any financial instrument arrangement. The Company has entered into natural gas derivative instruments and foreign currency derivative instruments with counterparties it views as creditworthy. However, the Company does attempt to mitigate its counterparty credit risk exposures by, among other things, entering into master netting agreements with some of these counterparties. The Company records derivative financial instruments as either assets or liabilities at fair value in its Consolidated Balance Sheets. The assets and liabilities recorded as of March 31, 2023 and September 30, 2022 were not material.

Derivatives qualify for treatment as hedges when there is a high correlation between the change in fair value of the derivative instrument and the related change in value of the underlying hedged item. Depending on the exposure being hedged, the Company must designate the hedging instrument as a fair value hedge, a cash flow hedge or a net investment in foreign operations hedge. For the qualifying derivative instruments that have been designated as hedges, the effective portion of the change in fair value is recognized through earnings when the underlying transaction being hedged affects earnings, allowing a derivative’s gains and losses to offset related results from the hedged item in the Consolidated Statements of Operations. Any ineffectiveness related to these instruments accounted for as hedges was not material for any of the periods presented. For derivative instruments that have not been designated as hedges, the entire change in fair value is recorded through earnings in the period of change.

Natural Gas Derivative Instruments

Natural gas is consumed at several of the Company’s production facilities, and changes in natural gas prices impact the Company’s operating margin. The Company seeks to reduce the earnings and cash flow impacts of changes in market prices of natural gas by fixing the purchase price of up to 90% of its forecasted natural gas usage. It is the Company’s policy to consider hedging portions of its natural gas usage up to 36 months in advance of the forecasted purchase. As of March 31, 2023, the Company had entered into natural gas derivative instruments to hedge a portion of its natural gas purchase requirements through September 2024. As of March 31, 2023 and September 30, 2022, the Company had agreements in place to hedge forecasted natural gas purchases of 2.2 million and 3.8 million MMBtus, respectively.

On March 1, 2023, the Company de-designated its natural gas cash flow hedges related to its Ogden, Utah production facility as the Company did not believe these hedges were probable of being highly effective in the second fiscal quarter of 2023. Beginning March 1, 2023, the change in the derivative was and will be recorded in other expense, net in the Consolidated Statements of Operations. Since the transactions are still probable of occurring, previously recognized amounts in AOCL of $0.5 million will remain in AOCL until the underlying forecasted transaction occurs. The Company recognized $0.5 million of expense in other expense, net on the Consolidated Statements of Operations during the three months ended March 31, 2023. Following the de-designation, these natural gas economic hedging instruments will be recorded at fair value through earnings unless re-designated or until settlement. Substantially all other natural gas derivative instruments held by the Company as of March 31, 2023 and September 30, 2022 qualified and were designated as cash flow hedges. As of March 31, 2023, the Company expects to reclassify from AOCL to earnings during the next twelve months $4.9 million of net losses on derivative instruments related to its natural gas hedges. Refer to Note 14 for the estimated fair value of the Company’s natural gas derivative instruments as of March 31, 2023 and September 30, 2022.

The following tables present the fair value of the Company’s derivatives (in millions):

	Asset Derivatives			Liability Derivatives
	Consolidated Balance Sheet Location	March 31, 2023		Consolidated Balance Sheet Location	March 31, 2023
Derivatives designated as hedging instruments:
Commodity contracts	Other current assets	$	0.7	Accrued expenses and other current liabilities	$	5.6
Commodity contracts	Other assets	—		Other noncurrent liabilities	0.6
Total derivatives designated as hedging instruments		0.7			6.2
Derivatives not designated as hedging instruments:
Commodity contracts	Other current assets	—		Accrued expenses and other current liabilities	0.5
Total derivatives not designated as hedging instruments		—			0.5
Total derivatives(a)		$	0.7		$	6.7

(a)The Company has master netting agreements with its commodity hedge counterparties and accordingly has netted in its Consolidated Balance Sheets $0.7 million of its commodity contracts that are in receivable positions against its contracts in payable positions.

	Asset Derivatives			Liability Derivatives
	Consolidated Balance Sheet Location	September 30, 2022		Consolidated Balance Sheet Location	September 30, 2022
Derivatives designated as hedging instruments:
Commodity contracts	Other current assets	$	2.7	Accrued expenses and other current liabilities	$	3.3
Commodity contracts	Other assets	0.2		Other noncurrent liabilities	0.7
Total derivatives designated as hedging instruments(a)		$	2.9		$	4.0

(a)The Company has master netting agreements with its commodity hedge counterparties and accordingly has netted in its Consolidated Balance Sheets $2.9 million of its commodity contracts that are in receivable positions against its contracts in payable positions.

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Fair Value Measurements

6 Months Ended

Mar. 31, 2023

Fair Value Disclosures [Abstract]

Fair Value Measurements

Fair Value Measurements:

The Company’s financial instruments are measured and reported at their estimated fair values. Fair value is the price that would be received to sell an asset or paid to transfer a liability in an orderly transaction. When available, the Company uses quoted prices in active markets to determine the fair values for its financial instruments (Level 1 inputs) or, absent quoted market prices, observable market-corroborated inputs over the term of the financial instruments (Level 2 inputs). The Company does not have any unobservable inputs that are not corroborated by market inputs (Level 3 inputs).

The Company holds marketable securities associated with its defined contribution and pre-tax savings plans, which are valued based on readily available quoted market prices. The Company utilizes derivative instruments to manage its risk of changes in natural gas prices and foreign exchange rates (see Note 13). The fair values of the natural gas and foreign currency derivative instruments are determined using market data of forward prices for all of the Company’s contracts. 

The estimated fair values for each type of instrument are presented below (in millions):

	March 31, 2023		Level One		Level Two		Level Three
Asset Class:
Mutual fund investments in a non-qualified savings plan(a)	$	2.5	$	2.5	$	—	$	—
Total Assets	$	2.5	$	2.5	$	—	$	—
Liability Class:
Derivatives designated as hedging instruments - natural gas instruments, net	$	(5.5)	$	—	$	(5.5)	$	—
Derivatives not designated as hedging instruments - natural gas instruments, net	(0.5)		—		(0.5)		—
Liabilities related to non-qualified savings plan	(2.5)		(2.5)		—		—
Total Liabilities	$	(8.5)	$	(2.5)	$	(6.0)	$	—

(a)Includes mutual fund investments of approximately 25% in common stock of large-cap U.S. companies, 5% in common stock of small to mid-cap U.S. companies, 10% in international companies, 15% in bond funds, 5% in short-term investments and 40% in blended funds.

	September 30, 2022		Level One		Level Two		Level Three
Asset Class:
Mutual fund investments in a non-qualified savings plan(a)	$	1.8	$	1.8	$	—	$	—
Total Assets	$	1.8	$	1.8	$	—	$	—
Liability Class:
Derivatives – natural gas instruments, net	$	(1.1)	$	—	$	(1.1)	$	—
Liabilities related to non-qualified savings plan	(1.8)		(1.8)		—		—
Total Liabilities	$	(2.9)	$	(1.8)	$	(1.1)	$	—

(a)Includes mutual fund investments of approximately 30% in the common stock of large-cap U.S. companies, 5% in the common stock of small to mid-cap U.S. companies, 10% in the common stock of international companies, 15% in bond funds, 5% in short-term investments and 35% in blended funds.

Cash and cash equivalents, receivables (net of allowance for doubtful accounts) and accounts payable are carried at cost, which approximates fair value due to their liquid and short-term nature. The Company’s investments related to its nonqualified retirement plan of $2.5 million at March 31, 2023 and $1.8 million at September 30, 2022, are stated at fair value based on quoted market prices. As of March 31, 2023 and September 30, 2022, the estimated fair value of the Company’s fixed-rate 4.875% Senior Notes due July 2024, based on available trading information (Level 2), totaled $237.4 million and $235.9 million, respectively, compared with the aggregate principal amount at maturity of $250.0 million. As of March 31, 2023 and September 30, 2022, the estimated fair value of the Company’s fixed-rate 6.75% Senior Notes due December 2027, based on available trading information (Level 2), totaled $472.5 million and $468.9 million, respectively, compared with the aggregate principal amount at maturity of $500.0 million. The fair value at March 31, 2023 and September 30, 2022 of amounts outstanding under the Company’s term loans and revolving credit facility, based upon available bid information received from the Company’s lender (Level 2), totaled approximately $16.7 million and $158.5 million, respectively, compared with the aggregate principal amount at maturity of $16.9 million and $168.4 million, respectively.

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Earnings per Share

6 Months Ended

Mar. 31, 2023

Earnings Per Share [Abstract]

Earnings per Share

Earnings per Share:

The Company calculates earnings per share using the two-class method. The two-class method requires allocating the Company’s net earnings to both common shares and participating securities. The following table sets forth the computation of basic and diluted earnings per common share (in millions, except for share and per-share data):

	Three Months Ended March 31,				Six Months Ended March 31,
	2023		2022		2023		2022
Numerator:
Net loss from continuing operations	$	(21.6)	$	(29.0)	$	(21.9)	$	(21.1)
Less: net earnings allocated to participating securities(a)	(0.1)		—		(0.2)		(0.1)
Net loss from continuing operations available to common stockholders	(21.7)		(29.0)		(22.1)		(21.2)
Net earnings from discontinued operations available to common stockholders	—		16.9		—		11.4
Net loss available to common stockholders	$	(21.7)	$	(12.1)	$	(22.1)	$	(9.8)
Denominator (in thousands):
Weighted-average common shares outstanding, shares for basic earnings per share	41,110		34,103		40,423		34,081
Weighted-average awards outstanding(b)	—		10		—		19
Shares for diluted earnings per share	41,110		34,113		40,423		34,100
Basic net loss from continuing operations per common share	$	(0.53)	$	(0.85)	$	(0.55)	$	(0.62)
Basic net earnings from discontinued operations per common share	—		0.49		—		0.33
Basic net loss per common share	$	(0.53)	$	(0.36)	$	(0.55)	$	(0.29)
Diluted net loss from continuing operations per common share	$	(0.53)	$	(0.85)	$	(0.55)	$	(0.62)
Diluted net earnings from discontinued operations per common share	—		0.49		—		0.33
Diluted net loss per common share	$	(0.53)	$	(0.36)	$	(0.55)	$	(0.29)

(a)Weighted participating securities include RSUs and PSUs that receive non-forfeitable dividends and consist of 439,000 and 477,000 weighted participating securities for the three and six months ended March 31, 2023, respectively and 407,000 and 419,000 weighted participating securities for the three and six months ended March 31, 2022, respectively.

(b)For the calculation of diluted net earnings (loss) per share, the Company uses the more dilutive of either the treasury stock method or the two-class method to determine the weighted-average number of outstanding common shares. In addition, the Company had 1,193,000 and 1,275,000 weighted-average equity awards outstanding for the three and six months ended March 31, 2023, respectively, and 1,125,000 and 1,115,000 weighted-average equity awards outstanding for the three and six months ended March 31, 2022, respectively that were anti-dilutive.

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Related Party Transactions

6 Months Ended

Mar. 31, 2023

Related Party Transactions [Abstract]

Related Party Transactions

Related Party Transactions:

As discussed in Note 12, on October 18, 2022, KII, through its KM&T subsidiary, purchased common stock representing an ownership interest of approximately 17% of the outstanding common stock of the Company. As part of the Stock Purchase Agreement, KM&T appointed two members to the Company’s board of directors, effective November 13, 2022. In addition, the companies continue to explore value creation opportunities.

During the three and six months ended March 31, 2023, the Company recorded SOP sales of approximately $0.9 million and $1.8 million, respectively, to certain subsidiaries of KII, compared to $0.7 million and $1.4 million during the three and six months ended March 31, 2022, respectively. As of March 31, 2023 and September 30, 2022, the Company had approximately $0.5 million and $0.4 million, respectively, of Receivables from related parties on its Consolidated Balance Sheets. Additionally, a subsidiary of KII has recently provided engineering services for the Company’s lithium development project for which it capitalized approximately $2.7 million into Property, Plant and Equipment, net, as of March 31, 2023. There were no amounts payable outstanding as of March 31, 2023.

On March 20, 2023, the Company paid a cash dividend to its stockholders of record at the close of business on March 10, 2023 in the amount of $0.15 per share, or $6.3 million in the aggregate. KM&T received approximately $1.0 million in respect to its common shares.

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Accounting Policies and Basis of Presentation (Policies)

6 Months Ended

Mar. 31, 2023

Accounting Policies [Abstract]

Basis of Consolidation

CMI is a holding company with no significant operations other than those of its wholly-owned subsidiaries. The consolidated financial statements include the accounts of CMI and its wholly-owned domestic and foreign subsidiaries. All significant intercompany balances and transactions have been eliminated in consolidation.

Basis of Presentation

The accompanying unaudited consolidated financial statements have been prepared in accordance with U.S. generally accepted accounting principles (“U.S. GAAP”) for interim financial information and with the instructions to Form 10-Q and Article 10 of Regulation S-X. Accordingly, they do not include all of the information and footnotes required by U.S. GAAP for complete consolidated financial statements. These unaudited consolidated financial statements should be read in conjunction with the consolidated financial statements of the Company for the annual period ended September 30, 2022, as filed with the Securities and Exchange Commission (the “SEC”) in its Annual Report on Form 10-K on December 14, 2022. In the opinion of management, all adjustments, consisting of normal recurring adjustments considered necessary for a fair presentation, have been included.

Significant and Recent Accounting Pronouncements

Significant Accounting Policies

The Company’s significant accounting policies are detailed in “Note 2 – Summary of Significant Accounting Policies” within Part II, Item 8 of its Annual Report on Form 10-K for the annual period ended September 30, 2022. The Company reports its financial results from discontinued operations and continuing operations separately to recognize the financial impact of disposal transactions apart from ongoing operations. Discontinued operations reporting occurs when a component or a group of components of an entity has been disposed or classified as held for sale and represents a strategic shift that has a major effect on the entity’s operations and financial results. In the Company’s Consolidated Statements of Cash Flows, the cash flows from discontinued operations are not separately classified. Unless otherwise indicated, amounts provided in these Notes pertain to continuing operations. See Note 2 for information on discontinued operations and Note 11 for information on the Company’s reportable segments.

Recent Accounting Pronouncements

In October 2021, the Financial Accounting Standards Board issued Accounting Standards Update (“ASU”) 2021-08, “Business Combinations (Topic 805): Accounting for Contract Assets and Contract Liabilities from Contracts with Customers.” ASU 2021-08 requires the company acquiring contract assets and contract liabilities obtained in a business combination to recognize and measure them in accordance with Accounting Standards Codification 606, “Revenue from Contracts with Customers”. Following the acquisition date, the company acquiring the business should record related revenue as if it had originated the contracts. Before the update, contract assets and contract liabilities from acquired contracts were recognized by the acquiring company at fair value on the acquisition date. The amendments are effective for fiscal years beginning after December 15, 2022, including interim periods within those fiscal years. Early adoption is permitted, including in interim periods, for any financial statements that have not yet been issued. The Company early adopted these requirements, effective on January 1, 2023, with no material impact to its consolidated financial statements.

Strategic Evaluation and Plan to Sell Businesses

Strategic Evaluation and Plan to Sell Businesses

Following an evaluation of the strategic fit of certain of the Company’s businesses and subsequent restructuring of its former South American Plant Nutrition segment to enable separate sales processes for its chemicals and specialty plant nutrition businesses and equity investment in Fermavi Eletroquímica Ltda. (“Fermavi”), in fiscal 2021 the Company’s Board of Directors approved the plan to sell each of these businesses and the North America micronutrient business (the “Specialty Businesses”) with a goal of reducing the Company’s leverage and enabling increased focus on optimizing the Company’s core businesses.

The Company concluded that the sale of the Specialty Businesses represented a strategic shift for the Company that would have a material effect on its operations and financial results. Consequently, the Specialty businesses were reclassified as discontinued operations on the Consolidated Statements of Operations. See Note 2 for further discussion of the sales of these businesses.

Unless otherwise indicated, amounts provided in these Notes pertain to continuing operations.

Derivative Financial Instruments

The Company is subject to various types of market risks, including interest rate risk, foreign currency exchange rate transaction and translation risk and commodity pricing risk. Management may take actions to mitigate the exposure to these types of risks, including entering into forward purchase contracts and other financial instruments. The Company manages a portion of its commodity pricing risks and foreign currency exchange rate risks by using derivative instruments. From time to time, the Company may enter into foreign exchange contracts to mitigate foreign exchange risk. The Company does not seek to engage in trading activities or take speculative positions with any financial instrument arrangement. The Company has entered into natural gas derivative instruments and foreign currency derivative instruments with counterparties it views as creditworthy. However, the Company does attempt to mitigate its counterparty credit risk exposures by, among other things, entering into master netting agreements with some of these counterparties. The Company records derivative financial instruments as either assets or liabilities at fair value in its Consolidated Balance Sheets. The assets and liabilities recorded as of March 31, 2023 and September 30, 2022 were not material. Derivatives qualify for treatment as hedges when there is a high correlation between the change in fair value of the derivative instrument and the related change in value of the underlying hedged item. Depending on the exposure being hedged, the Company must designate the hedging instrument as a fair value hedge, a cash flow hedge or a net investment in foreign operations hedge. For the qualifying derivative instruments that have been designated as hedges, the effective portion of the change in fair value is recognized through earnings when the underlying transaction being hedged affects earnings, allowing a derivative’s gains and losses to offset related results from the hedged item in the Consolidated Statements of Operations. Any ineffectiveness related to these instruments accounted for as hedges was not material for any of the periods presented. For derivative instruments that have not been designated as hedges, the entire change in fair value is recorded through earnings in the period of change.

Earnings Per Share

The Company calculates earnings per share using the two-class method. The two-class method requires allocating the Company’s net earnings to both common shares and participating securities.

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Discontinued Operations (Tables)

6 Months Ended

Mar. 31, 2023

Discontinued Operations and Disposal Groups [Abstract]

Disposal Groups, Including Discontinued Operations

The following table represents summarized Consolidated Statements of Operations information of discontinued operations (in millions):

	Three Months Ended March 31,			Six Months Ended March 31,
		2022			2022
Sales		$	24.3		$	46.7
Shipping and handling cost		1.3			2.5
Product cost		14.4			25.3
Gross profit		8.6			18.9
Selling, general and administrative expenses		1.4			3.0
Operating earnings		7.2			15.9
Interest expense		0.1			0.1
Gain on foreign exchange		(20.4)			(17.3)
Net loss on adjustment to fair value less estimated costs to sell		16.3			24.7
Other income, net		(0.3)			(0.5)
Earnings from discontinued operations before income taxes		11.5			8.9
Income tax benefit		(5.4)			(2.5)
Net earnings from discontinued operations		$	16.9		$	11.4

The significant components included in the Company’s Consolidated Statements of Cash Flows for discontinued operations are as follows (in millions):

	Six Months Ended March 31,
	2022
Loss on impairment of long-lived assets	$	24.7
Capital expenditures	(1.2)

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Inventories (Tables)

6 Months Ended

Mar. 31, 2023

Inventory Disclosure [Abstract]

Summary of Inventories

Inventories consist of the following (in millions):

	March 31, 2023		September 30, 2022
Finished goods	$	203.8	$	251.6
Raw materials and supplies	57.9		52.8
Total inventories	$	261.7	$	304.4

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Property, Plant and Equipment, Net (Tables)

6 Months Ended

Mar. 31, 2023

Property, Plant and Equipment [Abstract]

Summary of Property, Plant and Equipment, Net

Property, plant and equipment, net, consists of the following (in millions):

	March 31, 2023		September 30, 2022
Land, buildings and structures, and leasehold improvements	$	545.4	$	534.8
Machinery and equipment	1,071.1		1,026.3
Office furniture and equipment	58.6		56.8
Mineral interests	169.1		167.1
Construction in progress	57.2		64.3
	1,901.4		1,849.3
Less: accumulated depreciation and depletion	(1,118.8)		(1,072.7)
Property, plant and equipment, net	$	782.6	$	776.6

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Goodwill and Intangible Assets, Net (Tables)

6 Months Ended

Mar. 31, 2023

Goodwill and Intangible Assets Disclosure [Abstract]

Summary of Intangible Assets

Amounts related to the Company’s amortization of intangible assets are as follows (in millions):

	Three Months Ended March 31,				Six Months Ended March 31,
	2023		2022		2023		2022
Aggregate amortization expense	$	0.4	$	0.4	$	0.8	$	0.8

Summary of Goodwill

Amounts related to the Company’s goodwill are as follows (in millions):

	March 31, 2023		September 30, 2022
Plant Nutrition	$	51.0	$	50.9
Other	5.9		5.5
Total	$	56.9	$	56.4

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Long-Term Debt (Tables)

6 Months Ended

Mar. 31, 2023

Debt Disclosure [Abstract]

Summary of Long-Term Debt

Long-term debt consists of the following (in millions):

	March 31, 2023		September 30, 2022
4.875% Senior Notes due July 2024	$	250.0	$	250.0
Term Loan due January 2025	16.9		16.9
Revolving Credit Facility due January 2025	—		151.5
6.75% Senior Notes due December 2027	500.0		500.0
AR Securitization Facility expires June 2025	65.9		37.5
	832.8		955.9
Less unamortized debt issuance costs	(7.1)		(8.3)
Total debt	825.7		947.6
Less current portion	—		—
Long-term debt	$	825.7	$	947.6

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Operating Segments (Tables)

6 Months Ended

Mar. 31, 2023

Segment Reporting [Abstract]

Summary of Segment Information

Segment information is as follows (in millions):

Three Months Ended March 31, 2023	Salt		Plant Nutrition		Corporate & Other(a)(b)(c)		Total
Sales to external customers	$	360.5	$	47.7	$	2.9	$	411.1
Intersegment sales	—		1.4		(1.4)		—
Shipping and handling cost	124.0		6.1		—		130.1
Operating earnings (loss)(b)(c)	73.1		(0.7)		(24.5)		47.9
Depreciation, depletion and amortization	14.8		8.1		1.6		24.5
Total assets (as of end of period)	924.1		472.7		387.9		1,784.7

Three Months Ended March 31, 2022	Salt		Plant Nutrition		Corporate & Other(a)(b)		Total
Sales to external customers	$	391.3	$	54.3	$	2.9	$	448.5
Intersegment sales	—		0.7		(0.7)		—
Shipping and handling cost	153.4		6.7		—		160.1
Operating earnings (loss)(b)	49.3		4.4		(33.7)		20.0
Depreciation, depletion and amortization	16.2		8.8		2.9		27.9
Total assets (as of end of period)	925.4		444.4		266.4		1,636.2

Six Months Ended March 31, 2023	Salt		Plant Nutrition		Corporate & Other(a)(b)(c)		Total
Sales to external customers	$	668.6	$	89.3	$	5.6	$	763.5
Intersegment sales	—		4.3		(4.3)		—
Shipping and handling cost	226.7		10.8		—		237.5
Operating earnings (loss)(b)(c)	120.2		10.3		(54.7)		75.8
Depreciation, depletion and amortization	28.7		16.4		3.3		48.4

Six Months Ended March 31, 2022	Salt		Plant Nutrition		Corporate & Other(a)(b)		Total
Sales to external customers	$	665.2	$	108.9	$	5.9	$	780.0
Intersegment sales	—		3.1		(3.1)		—
Shipping and handling cost	241.8		14.0		—		255.8
Operating earnings (loss)(b)	88.7		13.9		(62.2)		40.4
Depreciation, depletion and amortization	32.4		17.6		6.2		56.2

Summary of Disaggregated Revenue by Product Type

Disaggregated revenue by product type is as follows (in millions):

Three Months Ended March 31, 2023	Salt		Plant Nutrition		Corporate & Other(a)		Total
Highway Deicing Salt	$	273.7	$	—	$	—	$	273.7
Consumer & Industrial Salt	86.8		—		—		86.8
SOP	—		49.1		—		49.1
Eliminations & Other	—		(1.4)		2.9		1.5
Sales to external customers	$	360.5	$	47.7	$	2.9	$	411.1

Three Months Ended March 31, 2022	Salt		Plant Nutrition		Corporate & Other(a)		Total
Highway Deicing Salt	$	300.1	$	—	$	—	$	300.1
Consumer & Industrial Salt	91.2		—		—		91.2
SOP	—		55.0		—		55.0
Eliminations & Other	—		(0.7)		2.9		2.2
Sales to external customers	$	391.3	$	54.3	$	2.9	$	448.5

Six Months Ended March 31, 2023	Salt		Plant Nutrition		Corporate & Other(a)		Total
Highway Deicing Salt	$	464.0	$	—	$	—	$	464.0
Consumer & Industrial Salt	204.6		—		—		204.6
SOP	—		93.6		—		93.6
Eliminations & Other	—		(4.3)		5.6		1.3
Sales to external customers	$	668.6	$	89.3	$	5.6	$	763.5

Six Months Ended March 31, 2022	Salt		Plant Nutrition		Corporate & Other(a)		Total
Highway Deicing Salt	$	463.8	$	—	$	—	$	463.8
Consumer & Industrial Salt	201.4		—		—		201.4
SOP	—		112.0		—		112.0
Eliminations & Other	—		(3.1)		5.9		2.8
Sales to external customers	$	665.2	$	108.9	$	5.9	$	780.0

(a)Corporate and Other includes corporate entities, records management operations, equity method investments, lithium development costs and other incidental operations and eliminations. Operating earnings (loss) for corporate and other includes indirect corporate overhead, including costs for general corporate governance and oversight, lithium-related expenses, as well as costs for the human resources, information technology, legal and finance functions.

(b)Corporate operating results for the three and six months ended March 31, 2023 include net reimbursements related to the settled SEC investigation of $0.4 million and $0.1 million, respectively. Corporate operating results for the three and six months ended March 31, 2022 include executive transition costs of $0.5 million and $3.8 million, respectively, and a contingent loss accrual and costs related to the SEC investigation of $13.6 million and $16.7 million, respectively. Refer to Note 10 for more information regarding the SEC investigation.

(c)In April 2023, the Company took initial steps to align its cost structure to its current business needs. These initiatives resulted in restructuring charges of $3.3 million, which impacted Corporate operating results for the three and six months ended March 31, 2023.

Summary of Revenue by Geographic Area

The Company’s revenue by geographic area is as follows (in millions):

	Three Months Ended March 31,				Six Months Ended March 31,
Revenue	2023		2022		2023		2022
United States(a)	$	283.1	$	327.8	$	531.3	$	549.1
Canada	101.0		104.5		188.6		193.9
United Kingdom	23.2		15.6		37.3		35.4
Other	3.8		0.6		6.3		1.6
Total revenue	$	411.1	$	448.5	$	763.5	$	780.0

(a)United States sales exclude product sold to foreign customers at U.S. ports.

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Stockholders' Equity and Equity Instruments (Tables)

6 Months Ended

Mar. 31, 2023

Equity [Abstract]

Summary of Stock-Based Compensation Activity

The following table summarizes stock-based compensation activity during the six months ended March 31, 2023:

	Stock Options			RSUs			PSUs(a)
	Number	Weighted-average exercise price		Number	Weighted-average fair value		Number	Weighted-average fair value
Outstanding at September 30, 2022	774,580	$	60.68	208,735	$	63.02	331,359	$	71.51
Granted	—	—		238,075	38.29		183,974	68.33
Exercised(b)	—	—		—	—		—	—
Released from restriction(b)	—	—		(122,645)	61.80		—	—
Cancelled/expired	(24,962)	62.53		(12,501)	46.86		(109,276)	66.69
Outstanding at March 31, 2023	749,618	$	60.61	311,664	$	45.26	406,057	$	71.37

(a)Until the performance period is completed, PSUs are included in the table at the target level at their grant date and at that level represent one share of common stock per PSU.

(b)Common stock issued for exercised options and for vested and earned RSUs and PSUs was issued from treasury stock.

Summary of Components and Changes in Accumulated Other Comprehensive Income (Loss)

The components of and changes in AOCL are as follows (in millions):

Three Months Ended March 31, 2023(a)	Gains and (Losses) on Cash Flow Hedges		Defined Benefit Pension		Other Post-Employment Benefits		Foreign Currency		Total
Beginning balance	$	(4.4)	$	(2.6)	$	1.3	$	(100.6)	$	(106.3)
Other comprehensive (loss) income before reclassifications(b)	(1.8)		—		—		2.8		1.0
Amounts reclassified from AOCL	0.7		—		—		—		0.7
Net current period other comprehensive (loss) income	(1.1)		—		—		2.8		1.7
Ending balance	$	(5.5)	$	(2.6)	$	1.3	$	(97.8)	$	(104.6)

Three Months Ended March 31, 2022(a)	Gains and (Losses) on Cash Flow Hedges		Defined Benefit Pension		Foreign Currency		Total
Beginning balance	$	1.1	$	(5.3)	$	(112.0)	$	(116.2)
Other comprehensive income before reclassifications(b)	1.6		—		10.7		12.3
Amounts reclassified from AOCL	(0.6)		0.1		—		(0.5)
Net current period other comprehensive income	1.0		0.1		10.7		11.8
Ending balance	$	2.1	$	(5.2)	$	(101.3)	$	(104.4)

Six Months Ended March 31, 2023(a)	Gains and (Losses) on Cash Flow Hedges		Defined Benefit Pension		Other Post-Employment Benefits		Foreign Currency		Total
Beginning balance	$	(1.6)	$	(2.7)	$	1.3	$	(112.3)	$	(115.3)
Other comprehensive (loss) income before reclassifications(b)	(4.2)		—		—		14.5		10.3
Amounts reclassified from AOCL	0.3		0.1		—		—		0.4
Net current period other comprehensive (loss) income	(3.9)		0.1		—		14.5		10.7
Ending balance	$	(5.5)	$	(2.6)	$	1.3	$	(97.8)	$	(104.6)

Six Months Ended March 31, 2022(a)	Gains and (Losses) on Cash Flow Hedges		Defined Benefit Pension		Foreign Currency		Total
Beginning balance	$	3.1	$	(5.4)	$	(108.2)	$	(110.5)
Other comprehensive income before reclassifications(b)	0.7		—		6.9		7.6
Amounts reclassified from AOCL	(1.7)		0.2		—		(1.5)
Net current period other comprehensive (loss) income	(1.0)		0.2		6.9		6.1
Ending balance	$	2.1	$	(5.2)	$	(101.3)	$	(104.4)

(a)With the exception of the CTA, for which no tax effect is recorded, the changes in the components of AOCL presented in the tables above are reflected net of applicable income taxes.

(b)The Company recorded foreign exchange (loss) of $(0.1) million and $(1.4) million in the three and six months ended March 31, 2023, respectively, and $(1.9) million and $(0.7) million in the three and six months ended March 31, 2022, respectively, in AOCL related to intercompany notes which were deemed to be of a long-term investment nature.

Summary of Reclassifications out of Accumulated Other Comprehensive Income

The amounts reclassified from AOCL to expense (income) for the three and six months ended March 31, 2023 and 2022, are shown below (in millions):

	Amount Reclassified from AOCL
	Three Months Ended March 31,				Six Months Ended March 31,				Line Item Impacted in the Consolidated Statements of Operations
	2023		2022		2023		2022
Loss (Gain) on cash flow hedges:
Natural gas instruments	$	1.0	$	(0.9)	$	0.5	$	(2.3)	Product cost
Income tax expense	(0.3)		0.3		(0.2)		0.6
Reclassifications, net of income taxes	0.7		(0.6)		0.3		(1.7)
Amortization of defined benefit pension:
Amortization of loss	—		0.1		0.1		0.2		Product cost
Income tax benefit	—		—		—		—
Reclassifications, net of income taxes	—		0.1		0.1		0.2
Amortization of other post-employment benefits:
Amortization of loss	—		—		—		—		Product cost
Income tax benefit	—		—		—		—
Reclassifications, net of income taxes	—		—		—		—
Total reclassifications, net of income taxes	$	0.7	$	(0.5)	$	0.4	$	(1.5)

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Derivative Financial Instruments (Tables)

6 Months Ended

Mar. 31, 2023

Derivative Instruments and Hedging Activities Disclosure [Abstract]

Summary of Fair Value of Hedges

The following tables present the fair value of the Company’s derivatives (in millions):

	Asset Derivatives			Liability Derivatives
	Consolidated Balance Sheet Location	March 31, 2023		Consolidated Balance Sheet Location	March 31, 2023
Derivatives designated as hedging instruments:
Commodity contracts	Other current assets	$	0.7	Accrued expenses and other current liabilities	$	5.6
Commodity contracts	Other assets	—		Other noncurrent liabilities	0.6
Total derivatives designated as hedging instruments		0.7			6.2
Derivatives not designated as hedging instruments:
Commodity contracts	Other current assets	—		Accrued expenses and other current liabilities	0.5
Total derivatives not designated as hedging instruments		—			0.5
Total derivatives(a)		$	0.7		$	6.7

(a)The Company has master netting agreements with its commodity hedge counterparties and accordingly has netted in its Consolidated Balance Sheets $0.7 million of its commodity contracts that are in receivable positions against its contracts in payable positions.

	Asset Derivatives			Liability Derivatives
	Consolidated Balance Sheet Location	September 30, 2022		Consolidated Balance Sheet Location	September 30, 2022
Derivatives designated as hedging instruments:
Commodity contracts	Other current assets	$	2.7	Accrued expenses and other current liabilities	$	3.3
Commodity contracts	Other assets	0.2		Other noncurrent liabilities	0.7
Total derivatives designated as hedging instruments(a)		$	2.9		$	4.0

(a)The Company has master netting agreements with its commodity hedge counterparties and accordingly has netted in its Consolidated Balance Sheets $2.9 million of its commodity contracts that are in receivable positions against its contracts in payable positions.

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Fair Value Measurements (Tables)

6 Months Ended

Mar. 31, 2023

Fair Value Disclosures [Abstract]

Schedule of Fair Value, Assets and Liabilities Measured on Recurring Basis

The estimated fair values for each type of instrument are presented below (in millions):

	March 31, 2023		Level One		Level Two		Level Three
Asset Class:
Mutual fund investments in a non-qualified savings plan(a)	$	2.5	$	2.5	$	—	$	—
Total Assets	$	2.5	$	2.5	$	—	$	—
Liability Class:
Derivatives designated as hedging instruments - natural gas instruments, net	$	(5.5)	$	—	$	(5.5)	$	—
Derivatives not designated as hedging instruments - natural gas instruments, net	(0.5)		—		(0.5)		—
Liabilities related to non-qualified savings plan	(2.5)		(2.5)		—		—
Total Liabilities	$	(8.5)	$	(2.5)	$	(6.0)	$	—

(a)Includes mutual fund investments of approximately 25% in common stock of large-cap U.S. companies, 5% in common stock of small to mid-cap U.S. companies, 10% in international companies, 15% in bond funds, 5% in short-term investments and 40% in blended funds.

	September 30, 2022		Level One		Level Two		Level Three
Asset Class:
Mutual fund investments in a non-qualified savings plan(a)	$	1.8	$	1.8	$	—	$	—
Total Assets	$	1.8	$	1.8	$	—	$	—
Liability Class:
Derivatives – natural gas instruments, net	$	(1.1)	$	—	$	(1.1)	$	—
Liabilities related to non-qualified savings plan	(1.8)		(1.8)		—		—
Total Liabilities	$	(2.9)	$	(1.8)	$	(1.1)	$	—

(a)Includes mutual fund investments of approximately 30% in the common stock of large-cap U.S. companies, 5% in the common stock of small to mid-cap U.S. companies, 10% in the common stock of international companies, 15% in bond funds, 5% in short-term investments and 35% in blended funds.

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Earnings per Share (Tables)

6 Months Ended

Mar. 31, 2023

Earnings Per Share [Abstract]

Summary of Basic and Diluted Earnings Per Common Share

The following table sets forth the computation of basic and diluted earnings per common share (in millions, except for share and per-share data):

	Three Months Ended March 31,				Six Months Ended March 31,
	2023		2022		2023		2022
Numerator:
Net loss from continuing operations	$	(21.6)	$	(29.0)	$	(21.9)	$	(21.1)
Less: net earnings allocated to participating securities(a)	(0.1)		—		(0.2)		(0.1)
Net loss from continuing operations available to common stockholders	(21.7)		(29.0)		(22.1)		(21.2)
Net earnings from discontinued operations available to common stockholders	—		16.9		—		11.4
Net loss available to common stockholders	$	(21.7)	$	(12.1)	$	(22.1)	$	(9.8)
Denominator (in thousands):
Weighted-average common shares outstanding, shares for basic earnings per share	41,110		34,103		40,423		34,081
Weighted-average awards outstanding(b)	—		10		—		19
Shares for diluted earnings per share	41,110		34,113		40,423		34,100
Basic net loss from continuing operations per common share	$	(0.53)	$	(0.85)	$	(0.55)	$	(0.62)
Basic net earnings from discontinued operations per common share	—		0.49		—		0.33
Basic net loss per common share	$	(0.53)	$	(0.36)	$	(0.55)	$	(0.29)
Diluted net loss from continuing operations per common share	$	(0.53)	$	(0.85)	$	(0.55)	$	(0.62)
Diluted net earnings from discontinued operations per common share	—		0.49		—		0.33
Diluted net loss per common share	$	(0.53)	$	(0.36)	$	(0.55)	$	(0.29)

(a)Weighted participating securities include RSUs and PSUs that receive non-forfeitable dividends and consist of 439,000 and 477,000 weighted participating securities for the three and six months ended March 31, 2023, respectively and 407,000 and 419,000 weighted participating securities for the three and six months ended March 31, 2022, respectively.

(b)For the calculation of diluted net earnings (loss) per share, the Company uses the more dilutive of either the treasury stock method or the two-class method to determine the weighted-average number of outstanding common shares. In addition, the Company had 1,193,000 and 1,275,000 weighted-average equity awards outstanding for the three and six months ended March 31, 2023, respectively, and 1,125,000 and 1,115,000 weighted-average equity awards outstanding for the three and six months ended March 31, 2022, respectively that were anti-dilutive.

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Discontinued Operations - Narrative (Details) R$ in Millions, $ in Millions						3 Months Ended		6 Months Ended	9 Months Ended
	Mar. 31, 2023 BRL (R$)	Apr. 20, 2022 USD ($)	Aug. 20, 2021 USD ($)	Jul. 01, 2021 USD ($)	Jun. 28, 2021 BRL (R$)	Jun. 30, 2022 USD ($)	Mar. 31, 2022 USD ($)	Mar. 31, 2022 USD ($)	Jun. 30, 2022 USD ($)	Apr. 07, 2022 USD ($)	May 04, 2021 USD ($)	Mar. 23, 2021 BRL (R$)
Fermavi
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Deferred purchase price | R$	R$ 22.5				R$ 30.0
Potential proceeds from sale of investments			$ 2.9		R$ 45.0
Deferred proceeds receivable			$ 4.8
Discontinued Operations, Held-for-sale or Disposed of by Sale
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Gain (loss) on disposal							$ (16.3)	$ (24.7)
Release of accumulated currency translation adjustment							$ 20.4	$ 17.3
Discontinued Operations, Held-for-sale or Disposed of by Sale | Plant Nutrition South America
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Proceeds from sale of business				$ 318.4
Additional earn out payment										$ 18.5		R$ 88.0
Discontinued Operations, Held-for-sale or Disposed of by Sale | North America Micronutrient Assets
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Gross proceeds received											$ 56.7
Discontinued Operations, Held-for-sale or Disposed of by Sale | South America Chemicals Business
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Gross proceeds received		$ 51.5
Cash on hand		6.4
Selling costs		2.4
Loss recovery on sale						$ 1.6
Gain (loss) on disposal									$ (23.1)
Release of accumulated currency translation adjustment		$ 49.5

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Discontinued Operations - Schedule of Discontinued Operations (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Mar. 31, 2023	Mar. 31, 2022	Mar. 31, 2023	Mar. 31, 2022
Disposal Group, Including Discontinued Operation, Income Statement Disclosures [Abstract]
Net earnings from discontinued operations	$ 0.0	$ 16.9	$ 0.0	$ 11.4
Discontinued Operations, Held-for-sale or Disposed of by Sale
Disposal Group, Including Discontinued Operation, Income Statement Disclosures [Abstract]
Sales		24.3		46.7
Gross profit		8.6		18.9
Selling, general and administrative expenses		1.4		3.0
Operating earnings		7.2		15.9
Interest expense		0.1		0.1
Gain on foreign exchange		(20.4)		(17.3)
Net loss on adjustment to fair value less estimated costs to sell		16.3		24.7
Other income, net		(0.3)		(0.5)
Earnings from discontinued operations before income taxes		11.5		8.9
Income tax benefit		(5.4)		(2.5)
Net earnings from discontinued operations		16.9		11.4
Disposal Group, Including Discontinued Operation, Additional Disclosures [Abstract]
Loss on impairment of long-lived assets		24.7
Capital expenditures		(1.2)
Discontinued Operations, Held-for-sale or Disposed of by Sale | Shipping and handling cost
Disposal Group, Including Discontinued Operation, Income Statement Disclosures [Abstract]
Cost of goods and services sold		1.3		2.5
Discontinued Operations, Held-for-sale or Disposed of by Sale | Product cost
Disposal Group, Including Discontinued Operation, Income Statement Disclosures [Abstract]
Cost of goods and services sold		$ 14.4		$ 25.3

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Revenues (Details)	6 Months Ended
	Mar. 31, 2023
Revenue from Contract with Customer [Abstract]
Payment terms for delivery	30 days

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Inventories (Details) - USD ($) $ in Millions	Mar. 31, 2023	Sep. 30, 2022
Inventory Disclosure [Abstract]
Finished goods	$ 203.8	$ 251.6
Raw materials and supplies	57.9	52.8
Total inventories	$ 261.7	$ 304.4

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Property, Plant and Equipment, Net (Details) - USD ($) $ in Millions	Mar. 31, 2023	Sep. 30, 2022
Property, Plant and Equipment [Line Items]
Total property plant and equipment	$ 1,901.4	$ 1,849.3
Less: accumulated depreciation and depletion	(1,118.8)	(1,072.7)
Property, plant and equipment, net	782.6	776.6
Land, buildings and structures, and leasehold improvements
Property, Plant and Equipment [Line Items]
Total property plant and equipment	545.4	534.8
Machinery and equipment
Property, Plant and Equipment [Line Items]
Total property plant and equipment	1,071.1	1,026.3
Office furniture and equipment
Property, Plant and Equipment [Line Items]
Total property plant and equipment	58.6	56.8
Mineral interests
Property, Plant and Equipment [Line Items]
Total property plant and equipment	169.1	167.1
Construction in progress
Property, Plant and Equipment [Line Items]
Total property plant and equipment	$ 57.2	$ 64.3

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Goodwill and Intangible Assets, Net (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Mar. 31, 2023	Mar. 31, 2022	Mar. 31, 2023	Mar. 31, 2022	Sep. 30, 2022
Goodwill [Line Items]
Aggregate amortization expense	$ 0.4	$ 0.4	$ 0.8	$ 0.8
Goodwill	56.9		56.9		$ 56.4
Other
Goodwill [Line Items]
Goodwill	5.9		5.9		5.5
Plant Nutrition | Operating Segments
Goodwill [Line Items]
Goodwill	$ 51.0		$ 51.0		$ 50.9

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Equity Method Investments (Details) - USD ($) $ in Millions		3 Months Ended		6 Months Ended
	May 05, 2023	Mar. 31, 2023	Mar. 31, 2022	Mar. 31, 2023	Mar. 31, 2022	Sep. 30, 2022
Schedule of Equity Method Investments [Line Items]
Net loss in equity investee		$ (1.4)	$ (1.7)	$ (2.3)	$ (2.1)
Equity method investments		44.3		$ 44.3		$ 46.6
Subsequent Event | Fortress
Schedule of Equity Method Investments [Line Items]
Remaining interest acquired (as a percent)	55.00%
Cash consideration	$ 26.0
Contingent consideration	$ 28.0
Fortress
Schedule of Equity Method Investments [Line Items]
Investment in investee		$ 50.0
Ownership interest in investment		45.00%		45.00%
Net loss in equity investee		$ 1.0	1.2	$ 1.5	1.3
Basis difference		27.0		27.0
Equity method investments		44.3		44.3		45.8
Other Immaterial Investments
Schedule of Equity Method Investments [Line Items]
Net loss in equity investee		0.4	$ 0.5	0.8	$ 0.8
Equity method investments		$ 0.0		$ 0.0		$ 0.8

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Income Taxes (Details) - USD ($) $ in Millions	6 Months Ended
	Mar. 31, 2023	Sep. 30, 2022
Income Tax Disclosure [Line Items]
Nondeductible executive compensation	$ 1.0
U.S. Federal
Income Tax Disclosure [Line Items]
Deferred tax asset valuation allowance recorded	15.8
Foreign Tax Authority
Income Tax Disclosure [Line Items]
Net operating loss carryforwards	82.1	$ 94.1
Foreign Tax Authority | Canadian Tax Authority
Income Tax Disclosure [Line Items]
Total reassessments including interest	173.1
Amount of security posted in the form of a performance bond	143.6
Amount of security posted in the form of cash	36.7	36.7
State and Local | NOL carryforwards expire beginning in 2027
Income Tax Disclosure [Line Items]
Net operating loss carryforwards	$ 3.8	$ 3.2

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Long-Term Debt (Details) - USD ($)		3 Months Ended
	May 05, 2023	Mar. 31, 2023	Sep. 30, 2022
Debt Instrument [Line Items]
Long-term debt, gross		$ 832,800,000	$ 955,900,000
Less unamortized debt issuance costs		(7,100,000)	(8,300,000)
Total debt		825,700,000	947,600,000
Less current portion		0	0
Long-term debt		$ 825,700,000	947,600,000
Weighted average interest rate of debt (as a percent)		6.90%
Quarter ending December 31, 2022
Debt Instrument [Line Items]
Consolidated total net leverage ratio		500.00%
Quarter ending March 31, 2024
Debt Instrument [Line Items]
Consolidated total net leverage ratio		475.00%
Fiscal quarter ended June 30, 2024
Debt Instrument [Line Items]
Consolidated total net leverage ratio		450.00%
Term Loan due January 2025
Debt Instrument [Line Items]
Long-term debt, gross		$ 16,900,000	$ 16,900,000
Credit Facility Due 2028 | Subsequent Event | Minimum
Debt Instrument [Line Items]
Total debt	$ 50,000,000
Credit Facility Due 2028 | Subsequent Event | Maximum
Debt Instrument [Line Items]
Total debt	$ 75,000,000
Senior Notes | 4.875% Senior Notes due July 2024
Debt Instrument [Line Items]
Stated interest rate (as a percent)		4.875%	4.875%
Long-term debt, gross		$ 250,000,000.0	$ 250,000,000.0
Aggregate principal amount due at maturity		$ 250,000,000	$ 250,000,000
Senior Notes | 4.875% Senior Notes due July 2024 | Subsequent Event
Debt Instrument [Line Items]
Stated interest rate (as a percent)	4.875%
Senior Notes | 6.75% Senior Notes due December 2027
Debt Instrument [Line Items]
Stated interest rate (as a percent)		6.75%	6.75%
Long-term debt, gross		$ 500,000,000.0	$ 500,000,000.0
Senior Notes | Credit Facility Due 2028 | Subsequent Event
Debt Instrument [Line Items]
Aggregate principal amount due at maturity	$ 575,000,000
Spread on rate (as a percent)	0.25%
Senior Notes | 2023 Credit Agreement | Subsequent Event
Debt Instrument [Line Items]
Conversion ratio	4
Repayments of lines of credit	$ 250,000,000
Repayments of term loan balance	16,900,000
Line of Credit | AR Securitization Facility expires June 2025
Debt Instrument [Line Items]
Long-term debt, gross		65,900,000	37,500,000
Line of Credit | Revolving Credit Facility due January 2025 | Revolving Credit Facility due January 2025
Debt Instrument [Line Items]
Long-term debt, gross		0	$ 151,500,000
Maximum unrestricted cash		$ 50,000,000
Revolving Credit Facility due January 2025 | 2023 Credit Agreement | Subsequent Event
Debt Instrument [Line Items]
Aggregate principal amount due at maturity	200,000,000
Revolving Credit Facility due January 2025 | 2023 Credit Agreement | Subsequent Event | Minimum
Debt Instrument [Line Items]
Revolving commitment fee	300,000,000
Revolving Credit Facility due January 2025 | 2023 Credit Agreement | Subsequent Event | Maximum
Debt Instrument [Line Items]
Revolving commitment fee	375,000,000
Revolving Credit Facility due January 2025 | Line of Credit | Credit Facility Due 2028 | Subsequent Event
Debt Instrument [Line Items]
Aggregate principal amount due at maturity	375,000,000
Secured Debt | Line of Credit | Credit Facility Due 2028 | Subsequent Event
Debt Instrument [Line Items]
Aggregate principal amount due at maturity	$ 200,000,000

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Commitments and Contingencies (Details) - SEC Investigation - USD ($) $ in Millions	Sep. 29, 2022	Sep. 23, 2022
Loss Contingencies [Line Items]
Loss contingency, damages sought, value		$ 12
Loss contingency, damages paid, value	$ 2
Contingent loss accrual		$ 10

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Operating Segments (Details) $ in Millions	3 Months Ended		6 Months Ended
	Mar. 31, 2023 USD ($) segment	Mar. 31, 2022 USD ($)	Mar. 31, 2023 USD ($) segment	Mar. 31, 2022 USD ($)
Segment Reporting [Abstract]
Number of reportable segments | segment	2		2
Segment Reporting Information [Abstract]
Sales	$ 411.1	$ 448.5	$ 763.5	$ 780.0
Operating earnings (loss)	47.9	20.0	75.8	40.4
Depreciation, depletion and amortization	24.5	27.9	48.4	56.2
Total assets (as of end of period)	1,784.7	1,636.2	1,784.7	1,636.2
Costs related to ongoing SEC investigation	(0.4)	13.6	(0.1)	16.7
Executive transition costs		0.5		3.8
Restructuring charges	3.3		3.3
United States
Segment Reporting Information [Abstract]
Sales	283.1	327.8	531.3	549.1
Canada
Segment Reporting Information [Abstract]
Sales	101.0	104.5	188.6	193.9
United Kingdom
Segment Reporting Information [Abstract]
Sales	23.2	15.6	37.3	35.4
Other
Segment Reporting Information [Abstract]
Sales	3.8	0.6	6.3	1.6
Shipping and handling cost
Segment Reporting Information [Abstract]
Shipping and handling cost	130.1	160.1	237.5	255.8
Highway Deicing Salt
Segment Reporting Information [Abstract]
Sales	273.7	300.1	464.0	463.8
Consumer & Industrial Salt
Segment Reporting Information [Abstract]
Sales	86.8	91.2	204.6	201.4
SOP
Segment Reporting Information [Abstract]
Sales	49.1	55.0	93.6	112.0
Eliminations & Other
Segment Reporting Information [Abstract]
Sales	1.5	2.2
Operating Segments | Salt
Segment Reporting Information [Abstract]
Sales	360.5	391.3	668.6	665.2
Operating earnings (loss)	73.1	49.3	120.2	88.7
Depreciation, depletion and amortization	14.8	16.2	28.7	32.4
Total assets (as of end of period)	924.1	925.4	924.1	925.4
Operating Segments | Salt | Shipping and handling cost
Segment Reporting Information [Abstract]
Shipping and handling cost	124.0	153.4	226.7	241.8
Operating Segments | Salt | Highway Deicing Salt
Segment Reporting Information [Abstract]
Sales	273.7	300.1	464.0	463.8
Operating Segments | Salt | Consumer & Industrial Salt
Segment Reporting Information [Abstract]
Sales	86.8	91.2	204.6	201.4
Operating Segments | Salt | SOP
Segment Reporting Information [Abstract]
Sales	0.0	0.0	0.0	0.0
Operating Segments | Salt | Eliminations & Other
Segment Reporting Information [Abstract]
Sales	0.0	0.0	0.0	0.0
Operating Segments | Plant Nutrition
Segment Reporting Information [Abstract]
Sales	47.7	54.3	89.3	108.9
Operating earnings (loss)	(0.7)	4.4	10.3	13.9
Depreciation, depletion and amortization	8.1	8.8	16.4	17.6
Total assets (as of end of period)	472.7	444.4	472.7	444.4
Operating Segments | Plant Nutrition | Shipping and handling cost
Segment Reporting Information [Abstract]
Shipping and handling cost	6.1	6.7	10.8	14.0
Operating Segments | Plant Nutrition | Highway Deicing Salt
Segment Reporting Information [Abstract]
Sales	0.0	0.0	0.0	0.0
Operating Segments | Plant Nutrition | Consumer & Industrial Salt
Segment Reporting Information [Abstract]
Sales	0.0	0.0	0.0	0.0
Operating Segments | Plant Nutrition | SOP
Segment Reporting Information [Abstract]
Sales	49.1	55.0	93.6	112.0
Operating Segments | Plant Nutrition | Eliminations & Other
Segment Reporting Information [Abstract]
Sales	(1.4)	(0.7)	(4.3)	(3.1)
Corporate & Other
Segment Reporting Information [Abstract]
Sales	2.9	2.9	5.6	5.9
Operating earnings (loss)	(24.5)	(33.7)	(54.7)	(62.2)
Depreciation, depletion and amortization	1.6	2.9	3.3	6.2
Total assets (as of end of period)	387.9	266.4	387.9	266.4
Corporate & Other | Shipping and handling cost
Segment Reporting Information [Abstract]
Shipping and handling cost	0.0	0.0	0.0	0.0
Corporate & Other | Highway Deicing Salt
Segment Reporting Information [Abstract]
Sales	0.0	0.0	0.0	0.0
Corporate & Other | Consumer & Industrial Salt
Segment Reporting Information [Abstract]
Sales	0.0	0.0	0.0	0.0
Corporate & Other | SOP
Segment Reporting Information [Abstract]
Sales	0.0	0.0	0.0	0.0
Corporate & Other | Eliminations & Other
Segment Reporting Information [Abstract]
Sales	2.9	2.9	5.6	5.9
Intersegment Eliminations
Segment Reporting Information [Abstract]
Sales	(1.4)	(0.7)	(4.3)	(3.1)
Intersegment Eliminations | Eliminations & Other
Segment Reporting Information [Abstract]
Sales			1.3	2.8
Intersegment Eliminations | Salt
Segment Reporting Information [Abstract]
Sales	0.0	0.0	0.0	0.0
Intersegment Eliminations | Plant Nutrition
Segment Reporting Information [Abstract]
Sales	$ 1.4	$ 0.7	$ 4.3	$ 3.1

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Stockholders' Equity and Equity Instruments - Narrative (Details) - USD ($) $ / shares in Units, $ in Millions			1 Months Ended	6 Months Ended		12 Months Ended
	Oct. 18, 2022	Sep. 14, 2022	Feb. 28, 2022	Mar. 31, 2023	Mar. 31, 2022	Sep. 30, 2022	May 31, 2020
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Treasury stock reissued (in shares)						117,390
Tax deficiency from equity compensation awards recorded as an increase to income tax expense				$ 0.7
Compensation expense recorded during period pursuant to stock-based compensation plans				14.1	$ 9.2
Compensation expense to be paid in cash				$ 0.4	$ 1.4
Koch Minerals & Trading, LLC
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Ownership by noncontrolling interest (as a percent)	17.00%
Private Placement
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares issued		6,830,700
Sale of Stock, Price (in dollars per share)		$ 36.87
Net proceeds		$ 240.7
Advancement of development project	$ 200.0
Portion to reduce debt	$ 40.7
Stock Options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period				4 years
Options expiration period				7 years
Number of shares available from conversion (in shares)				1
RSUs
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares available from conversion (in shares)				1
Reissued shares of treasury stock (in shares)				115,123
TSR PSUs | Minimum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Performance period of PSUs				2 years
Percentage of shares earned				0.00%
TSR PSUs | Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Performance period of PSUs				3 years
Percentage of shares earned				300.00%
EBITDA Growth PSUs | Minimum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Percentage of shares earned				0.00%
EBITDA Growth PSUs | Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Percentage of shares earned				300.00%
Stock Payments
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Reissued shares of treasury stock (in shares)				58,287
Equity Awards
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares withheld related to vesting of RSUs and PSUs (in shares)				35,731
Fair value of stock withheld related to vesting of RSUs and PSUs				$ 1.6
2020 Incentive Award Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares authorized for issuance (in shares)							2,977,933
Shares authorized for issuance (in shares)			750,000
2020 Incentive Award Plan | RSUs
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Service period				3 years
2015 Incentive Award Plan | RSUs
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Service period				1 year

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Stockholders' Equity and Equity Instruments - Stock-Based Compensation Activity (Details)	6 Months Ended
	Mar. 31, 2023 $ / shares shares
Stock Options
Number
Outstanding at beginning of period (in shares)	774,580
Granted (in shares)	0
Exercised (in shares)	0
Released from restriction (in shares)	0
Cancelled/expired (in shares)	(24,962)
Outstanding at end of period (in shares)	749,618
Weighted-average exercise price
Weighted-average exercise price at beginning of period (in dollars per share) | $ / shares	$ 60.68
Weighted-average exercise price, granted (in dollars per share) | $ / shares	0
Weighted-average exercise price, exercised (in dollars per share) | $ / shares	0
Weighted-average exercise price, released from restriction (in dollars per share) | $ / shares	0
Weighted-average exercise price, cancelled/expired (in dollars per share) | $ / shares	62.53
Weighted-average exercise price at end of period (in dollars per share) | $ / shares	$ 60.61
RSUs
Number
Outstanding at beginning of period (in shares)	208,735
Granted (in shares)	238,075
Exercised (in shares)	0
Released from restriction (in shares)	(122,645)
Cancelled/expired (in shares)	(12,501)
Outstanding at end of period (in shares)	311,664
Weighted-average fair value
Weighted-average fair value at beginning of period (in dollars per share) | $ / shares	$ 63.02
Weighted-average fair value, granted (in dollars per share) | $ / shares	38.29
Weighted-average fair value, exercised (in dollars per share) | $ / shares	0
Weighted-average fair value, released from restriction (in dollars per share) | $ / shares	61.80
Weighted-average fair value, cancelled/expired (in dollars per share) | $ / shares	46.86
Weighted-average fair value at end of period (in dollars per share) | $ / shares	$ 45.26
PSUs
Number
Outstanding at beginning of period (in shares)	331,359
Granted (in shares)	183,974
Exercised (in shares)	0
Released from restriction (in shares)	0
Cancelled/expired (in shares)	(109,276)
Outstanding at end of period (in shares)	406,057
Weighted-average fair value
Weighted-average fair value at beginning of period (in dollars per share) | $ / shares	$ 71.51
Weighted-average fair value, granted (in dollars per share) | $ / shares	68.33
Weighted-average fair value, exercised (in dollars per share) | $ / shares	0
Weighted-average fair value, released from restriction (in dollars per share) | $ / shares	0
Weighted-average fair value, cancelled/expired (in dollars per share) | $ / shares	66.69
Weighted-average fair value at end of period (in dollars per share) | $ / shares	$ 71.37
PSU at grant date (in shares per unit)	1

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Stockholders' Equity and Equity Instruments - Components and Changes In AOCL (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Mar. 31, 2023	Mar. 31, 2022	Mar. 31, 2023	Mar. 31, 2022
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Beginning balance	$ 509.8	$ 288.0	$ 256.4	$ 293.1
Other comprehensive (loss) income before reclassifications	1.0	12.3	10.3	7.6
Amounts reclassified from accumulated other comprehensive loss	0.7	(0.5)	0.4	(1.5)
Net current period other comprehensive income	1.7	11.8	10.7	6.1
Ending balance	485.4	286.5	485.4	286.5
Gains (loss) on foreign exchange of intercompany notes of long-term nature	(0.1)	(1.9)	(1.4)	(0.7)
Gains and (Losses) on Cash Flow Hedges
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Beginning balance	(4.4)	1.1	(1.6)	3.1
Other comprehensive (loss) income before reclassifications	(1.8)	1.6	(4.2)	0.7
Amounts reclassified from accumulated other comprehensive loss	0.7	(0.6)	0.3	(1.7)
Net current period other comprehensive income	(1.1)	1.0	(3.9)	(1.0)
Ending balance	(5.5)	2.1	(5.5)	2.1
Benefit Plans
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Beginning balance		(5.3)	(2.7)	(5.4)
Other comprehensive (loss) income before reclassifications		0.0	0.0	0.0
Amounts reclassified from accumulated other comprehensive loss		0.1	0.1	0.2
Net current period other comprehensive income		0.1	0.1	0.2
Ending balance	(2.6)	(5.2)	(2.6)	(5.2)
Benefit Plans | Defined Benefit Pension
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Beginning balance	(2.6)
Other comprehensive (loss) income before reclassifications	0.0
Amounts reclassified from accumulated other comprehensive loss	0.0
Net current period other comprehensive income	0.0
Ending balance	(2.6)		(2.6)
Benefit Plans | Other Post-Employment Benefits
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Beginning balance	1.3		1.3
Other comprehensive (loss) income before reclassifications	0.0		0.0
Amounts reclassified from accumulated other comprehensive loss	0.0		0.0
Net current period other comprehensive income	0.0		0.0
Ending balance	1.3		1.3
Foreign Currency
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Beginning balance	(100.6)	(112.0)	(112.3)	(108.2)
Other comprehensive (loss) income before reclassifications	2.8	10.7	14.5	6.9
Amounts reclassified from accumulated other comprehensive loss	0.0	0.0	0.0	0.0
Net current period other comprehensive income	2.8	10.7	14.5	6.9
Ending balance	(97.8)	(101.3)	(97.8)	(101.3)
Total
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Beginning balance	(106.3)	(116.2)	(115.3)	(110.5)
Ending balance	$ (104.6)	$ (104.4)	$ (104.6)	$ (104.4)

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Stockholders' Equity and Equity Instruments - Reclassifications From AOCL (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Mar. 31, 2023	Mar. 31, 2022	Mar. 31, 2023	Mar. 31, 2022
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Income tax benefit (expense)	$ 55.1	$ 30.4	$ 67.0	$ 29.2
Net loss	(21.6)	(12.1)	(21.9)	(9.7)
Product cost
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Product cost	(195.8)	(223.8)	(370.8)	(399.7)
Amount Reclassified from AOCL
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Net loss	0.7	(0.5)	0.4	(1.5)
Amount Reclassified from AOCL | Loss (Gain) on cash flow hedges:
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Income tax benefit (expense)	(0.3)	0.3	(0.2)	0.6
Net loss	0.7	(0.6)	0.3	(1.7)
Amount Reclassified from AOCL | Loss (Gain) on cash flow hedges: | Natural gas instruments | Product cost
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Product cost	1.0	(0.9)	0.5	(2.3)
Amount Reclassified from AOCL | Amortization of defined benefit pension:
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Income tax benefit (expense)	0.0	0.0	0.0	0.0
Net loss	0.0	0.1	0.1	0.2
Amount Reclassified from AOCL | Amortization of defined benefit pension: | Product cost
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Product cost	0.0	0.1	0.1	0.2
Amount Reclassified from AOCL | Amortization of other post-employment benefits:
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Income tax benefit (expense)	0.0	0.0	0.0	0.0
Net loss	0.0	0.0	0.0	0.0
Amount Reclassified from AOCL | Amortization of other post-employment benefits: | Product cost
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Product cost	$ 0.0	$ 0.0	$ 0.0	$ 0.0

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Derivative Financial Instruments - Narrative (Details) MMBTU in Millions, $ in Millions	3 Months Ended		6 Months Ended		12 Months Ended
	Mar. 31, 2023 USD ($)	Mar. 31, 2022 USD ($)	Mar. 31, 2023 USD ($) MMBTU	Mar. 31, 2022 USD ($)	Sep. 30, 2022 USD ($) MMBTU	Mar. 01, 2023 USD ($)
Derivatives, Fair Value [Line Items]
Liability Derivatives	$ 6.7		$ 6.7
Expense recognized	(0.9)	$ 0.0	(1.0)	$ (0.1)
Derivatives Designated as Hedging Instruments
Derivatives, Fair Value [Line Items]
Liability Derivatives	6.2		6.2		$ 4.0
Not Designated as Hedging Instrument
Derivatives, Fair Value [Line Items]
Liability Derivatives	0.5		$ 0.5
Natural gas instruments
Derivatives, Fair Value [Line Items]
Notional amount (in MMBtus) | MMBTU			2.2		3.8
Expense recognized	$ 0.5
Net gains to be reclassified from accumulated other comprehensive loss to earnings during the next 12 months			$ 4.9
Natural gas instruments | Derivatives Designated as Hedging Instruments
Derivatives, Fair Value [Line Items]
Percent of forecasted usage to be hedged	90.00%		90.00%
Maximum period which the Company hedges in advance of forecasted purchase			36 months
Natural gas instruments | Derivatives Designated as Hedging Instruments | Accrued expenses and other current liabilities
Derivatives, Fair Value [Line Items]
Liability Derivatives	$ 5.6		$ 5.6		$ 3.3
Natural gas instruments | Not Designated as Hedging Instrument | Accrued expenses and other current liabilities
Derivatives, Fair Value [Line Items]
Liability Derivatives	$ 0.5		$ 0.5			$ 0.5

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Derivative Financial Instruments - Fair Value of Hedged Items (Details) - USD ($) $ in Millions	Mar. 31, 2023	Mar. 01, 2023	Sep. 30, 2022
Derivatives, Fair Value [Line Items]
Asset Derivatives	$ 0.7
Liability Derivatives	6.7
Derivatives Designated as Hedging Instruments
Derivatives, Fair Value [Line Items]
Asset Derivatives	0.7		$ 2.9
Liability Derivatives	6.2		4.0
Not Designated as Hedging Instrument
Derivatives, Fair Value [Line Items]
Asset Derivatives	0.0
Liability Derivatives	0.5
Natural gas instruments
Derivatives, Fair Value [Line Items]
Netting of contracts in a receivable position against contracts in payable position	0.7		2.9
Other current assets | Natural gas instruments | Derivatives Designated as Hedging Instruments
Derivatives, Fair Value [Line Items]
Asset Derivatives	0.7		2.7
Other current assets | Natural gas instruments | Not Designated as Hedging Instrument
Derivatives, Fair Value [Line Items]
Asset Derivatives	0.0
Other assets | Natural gas instruments | Derivatives Designated as Hedging Instruments
Derivatives, Fair Value [Line Items]
Asset Derivatives	0.0		0.2
Accrued expenses and other current liabilities | Natural gas instruments | Derivatives Designated as Hedging Instruments
Derivatives, Fair Value [Line Items]
Liability Derivatives	5.6		3.3
Accrued expenses and other current liabilities | Natural gas instruments | Not Designated as Hedging Instrument
Derivatives, Fair Value [Line Items]
Liability Derivatives	0.5	$ 0.5
Other noncurrent liabilities | Natural gas instruments | Derivatives Designated as Hedging Instruments
Derivatives, Fair Value [Line Items]
Liability Derivatives	$ 0.6		$ 0.7

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Fair Value Measurements - Summary of Estimated Fair Values (Details) - USD ($) $ in Millions	6 Months Ended	12 Months Ended
	Mar. 31, 2023	Sep. 30, 2022
Common Stock, Large Cap US Companies | Mutual Fund Investments, Concentration Risk | Investment Benchmark
Liability Class:
Investment concentration risk (as a percent)	25.00%	30.00%
Common Stock of Small to Mid Cap US Companies | Mutual Fund Investments, Concentration Risk | Investment Benchmark
Liability Class:
Investment concentration risk (as a percent)	5.00%	5.00%
Common Stock, International Companies | Mutual Fund Investments, Concentration Risk | Investment Benchmark
Liability Class:
Investment concentration risk (as a percent)	10.00%	10.00%
Bond Funds | Mutual Fund Investments, Concentration Risk | Investment Benchmark
Liability Class:
Investment concentration risk (as a percent)	15.00%	15.00%
Short-Term Investments | Mutual Fund Investments, Concentration Risk | Investment Benchmark
Liability Class:
Investment concentration risk (as a percent)	5.00%	5.00%
Blended Funds | Mutual Fund Investments, Concentration Risk | Investment Benchmark
Liability Class:
Investment concentration risk (as a percent)	40.00%	35.00%
Fair Value, Measurements, Recurring
Asset Class:
Mutual fund investments in a non-qualified savings plan	$ 2.5	$ 1.8
Total Assets	2.5	1.8
Liability Class:
Derivatives designated as hedging instruments - natural gas instruments, net		(1.1)
Liabilities related to non-qualified savings plan	(2.5)	(1.8)
Total Liabilities	(8.5)	(2.9)
Fair Value, Measurements, Recurring | Derivatives Designated as Hedging Instruments
Liability Class:
Derivatives designated as hedging instruments - natural gas instruments, net	(5.5)
Fair Value, Measurements, Recurring | Not Designated as Hedging Instrument
Liability Class:
Derivatives designated as hedging instruments - natural gas instruments, net	(0.5)
Fair Value, Measurements, Recurring | Level One
Asset Class:
Mutual fund investments in a non-qualified savings plan	2.5	1.8
Total Assets	2.5	1.8
Liability Class:
Derivatives designated as hedging instruments - natural gas instruments, net		0.0
Liabilities related to non-qualified savings plan	(2.5)	(1.8)
Total Liabilities	(2.5)	(1.8)
Fair Value, Measurements, Recurring | Level One | Derivatives Designated as Hedging Instruments
Liability Class:
Derivatives designated as hedging instruments - natural gas instruments, net	0.0
Fair Value, Measurements, Recurring | Level One | Not Designated as Hedging Instrument
Liability Class:
Derivatives designated as hedging instruments - natural gas instruments, net	0.0
Fair Value, Measurements, Recurring | Level Two
Asset Class:
Mutual fund investments in a non-qualified savings plan	0.0	0.0
Total Assets	0.0	0.0
Liability Class:
Derivatives designated as hedging instruments - natural gas instruments, net		(1.1)
Liabilities related to non-qualified savings plan	0.0	0.0
Total Liabilities	(6.0)	(1.1)
Fair Value, Measurements, Recurring | Level Two | Derivatives Designated as Hedging Instruments
Liability Class:
Derivatives designated as hedging instruments - natural gas instruments, net	(5.5)
Fair Value, Measurements, Recurring | Level Two | Not Designated as Hedging Instrument
Liability Class:
Derivatives designated as hedging instruments - natural gas instruments, net	(0.5)
Fair Value, Measurements, Recurring | Level Three
Asset Class:
Mutual fund investments in a non-qualified savings plan	0.0	0.0
Total Assets	0.0	0.0
Liability Class:
Derivatives designated as hedging instruments - natural gas instruments, net		0.0
Liabilities related to non-qualified savings plan	0.0	0.0
Total Liabilities	0.0	$ 0.0
Fair Value, Measurements, Recurring | Level Three | Derivatives Designated as Hedging Instruments
Liability Class:
Derivatives designated as hedging instruments - natural gas instruments, net	0.0
Fair Value, Measurements, Recurring | Level Three | Not Designated as Hedging Instrument
Liability Class:
Derivatives designated as hedging instruments - natural gas instruments, net	$ 0.0

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Fair Value Measurements - Narrative (Details) - USD ($)	Mar. 31, 2023	Sep. 30, 2022
Senior Notes | 4.875% Senior Notes due July 2024
Debt Instrument [Line Items]
Stated interest rate (as a percent)	4.875%	4.875%
Fair value of senior notes	$ 237,400,000	$ 235,900,000
Aggregate principal amount due at maturity	$ 250,000,000	$ 250,000,000
Senior Notes | 6.75% Senior Notes due December 2027
Debt Instrument [Line Items]
Stated interest rate (as a percent)	6.75%	6.75%
Fair value of senior notes	$ 472,500,000	$ 468,900,000
Senior Notes due 2027
Debt Instrument [Line Items]
Debt fair value amount	500,000,000	500,000,000
Term Loan
Debt Instrument [Line Items]
Aggregate principal amount due at maturity	16,900,000	168,400,000
Fair value of credit agreement debt	16,700,000	158,500,000
Fair Value, Measurements, Recurring
Debt Instrument [Line Items]
Mutual fund investments in a non-qualified savings plan	$ 2,500,000	$ 1,800,000

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Earnings per Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Millions	3 Months Ended		6 Months Ended
	Mar. 31, 2023	Mar. 31, 2022	Mar. 31, 2023	Mar. 31, 2022
Numerator:
Net loss from continuing operations	$ (21.6)	$ (29.0)	$ (21.9)	$ (21.1)
Less: net earnings allocated to participating securities	(0.1)	0.0	(0.2)	(0.1)
Net loss from continuing operations available to common stockholders	(21.7)	(29.0)	(22.1)	(21.2)
Net earnings from discontinued operations available to common stockholders	0.0	16.9	0.0	11.4
Net loss available to common stockholders	$ (21.7)	$ (12.1)	$ (22.1)	$ (9.8)
Denominator (in thousands):
Weighted-average common shares outstanding, shares for basic earnings per share (in shares)	41,110	34,103	40,423	34,081
Weighted-average awards outstanding (in shares)	0	10	0	19
Shares for diluted earnings per share (in shares)	41,110	34,113	40,423	34,100
Basic net loss from continuing operations per common share (in dollars per share)	$ (0.53)	$ (0.85)	$ (0.55)	$ (0.62)
Basic net earnings from discontinued operations per common share (in dollars per share)	0	0.49	0	0.33
Basic net loss per common share (in dollars per share)	(0.53)	(0.36)	(0.55)	(0.29)
Diluted net loss from continuing operations per common share (in dollars per share)	(0.53)	(0.85)	(0.55)	(0.62)
Diluted net earnings from discontinued operations per common share (in dollars per share)	0	0.49	0	0.33
Diluted net loss per common share (in dollars per share)	$ (0.53)	$ (0.36)	$ (0.55)	$ (0.29)
Participating securities (in shares)	439,000	407,000	477,000	419,000
Stock Options
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Anti-dilutive weighted options outstanding (in shares)	1,193,000	1,125,000	1,275,000	1,115,000

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Related Party Disclosures (Details) $ / shares in Units, $ in Millions		3 Months Ended		6 Months Ended
	Mar. 20, 2023 USD ($) $ / shares	Mar. 31, 2023 USD ($)	Mar. 31, 2022 USD ($)	Mar. 31, 2023 USD ($)	Mar. 31, 2022 USD ($)	Nov. 13, 2022 board_member	Oct. 18, 2022	Sep. 30, 2022 USD ($)
Related Party Transaction [Line Items]
Number of board members | board_member						2
Cash dividend declared (in dollars per share) | $ / shares	$ 0.15
Payments of dividends	$ 6.3			$ 12.6	$ 10.5
Koch Minerals & Trading, LLC
Related Party Transaction [Line Items]
Revenue		$ 1.8	$ 0.7	0.9	$ 1.4
Accounts receivable		0.5		0.5				$ 0.4
Capitalized cost		2.7		2.7
Accounts payable		$ 0.0		$ 0.0
Payments of dividends	$ 1.0
Koch Minerals & Trading, LLC
Related Party Transaction [Line Items]
Ownership by noncontrolling interest (as a percent)							17.00%