CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($)	12 Months Ended
	Jul. 31, 2017	Jul. 31, 2016	Jul. 31, 2015
CASH PROVIDED BY (USED IN): OPERATING ACTIVITIES
Net loss for the year	$ (17,971,056)	$ (17,329,872)	$ (23,361,928)
Adjustments to reconcile net loss to cash flows in operating activities
Stock-based compensation	3,769,370	3,084,163	5,617,748
Depreciation, amortization and accretion	497,728	875,724	2,193,160
Amortization of long-term debt discount	1,156,657	1,245,615	1,353,773
Impairment loss on mineral properties	297,942	97,114	349,805
Inventory write-down	60,694	0	0
Re-valuation of asset retirement obligations	(187,255)	(308,398)	0
Loss on disposition of assets	1,055	2,186	38
Deferred income tax benefit	(34,355)	(32,239)	(35,413)
Realized loss on available-for-sale securities	0	0	3,023
Loss on settlement of liabilities	49,002	46,968	0
Changes in operating assets and liabilities
Inventories	2,960	(23,317)	1,316,959
Prepaid expenses and deposits	190,580	(85,673)	46,866
Other current assets	(68,965)	(30,165)	(2,954)
Accounts payable and accrued liabilities	1,816,199	(622,713)	243,686
NET CASH FLOWS USED IN OPERATING ACTIVITIES	(10,419,444)	(13,080,607)	(12,275,237)
FINANCING ACTIVITIES
Shares issuance for cash, net of issuance costs	26,889,996	10,209,632	9,650,530
Due to related parties	768	(14,660)	3,426
NET CASH FLOWS PROVIDED BY FINANCING ACTIVITIES	26,890,764	10,194,972	9,653,956
INVESTING ACTIVITIES
Net cash received from (used in) asset acquisitions	34,972	(46,084)	0
Investment in mineral rights and properties	0	0	(78,626)
Purchase of property, plant and equipment	(56,407)	(18,934)	(23,041)
Purchase of equity-accounted investment	(151,676)	0	0
Increase in other long-term assets	(864,806)	0	0
Purchase of short-term investments	(16,000,671)	0	0
Redemption of short-term investments	6,000,671	0	0
Proceeds from disposition of assets	0	818	2,860
Proceeds from the release of reclamation deposits	0	0	5,663,158
Payment of surety bonds collateral	0	0	(1,690,208)
Increase in reclamation deposits	(1)	(2)	(346)
NET CASH FLOWS (USED IN) PROVIDED BY INVESTING ACTIVITIES	(11,037,918)	(64,202)	3,873,797
NET CASH FLOWS	5,433,402	(2,949,837)	1,252,516
CASH AND CASH EQUIVALENTS, BEGINNING OF YEAR	7,142,571	10,092,408	8,839,892
CASH AND CASH EQUIVALENTS, END OF YEAR	$ 12,575,973	$ 7,142,571	$ 10,092,408