SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Revenue (Details)	3 Months Ended		6 Months Ended
	Jul. 31, 2022 USD ($) shares	Jul. 31, 2021 USD ($) shares	Jul. 31, 2022 USD ($) contract item MT shares	Jul. 31, 2021 USD ($) shares	Jan. 31, 2022 USD ($)
Disaggregation of Revenue [Line Items]
Number of units outstanding | shares	13,120,010	13,120,010	13,120,010	13,120,010
Revenue from Contract with Customer [Abstract]
Royalty income (loss)	$ (4,401,049)	$ 27,744,036	$ 9,794,440	$ 37,146,203
Base overriding royalties, first tier portion percentage			90.00%
Base overriding royalties, first tier shipment ceiling (in million tons) | MT			4
Base overriding royalties, second tier portion percentage			85.00%
Base overriding royalties, second tier shipment ceiling (in million tons) | MT			2
Base overriding royalties, third tier portion percentage			25.00%
Base overriding royalties, third tier shipment threshold (in million tons) | MT			6
Base overriding royalties, number of volume thresholds for transaction price | item			4
Base overriding royalties, volume threshold for transaction price | MT			1
Accrued income receivable	9,476		$ 9,476		$ 4,631,510
Number of customer contracts | contract			1
Contract asset					1,431,633
Contract asset	0		$ 0		$ 1,431,633
Contract liability	0		0
Base Overriding Royalties
Revenue from Contract with Customer [Abstract]
Royalty income (loss)	(4,402,501)	16,645,464	3,829,720	22,284,617
Bonus Royalties
Revenue from Contract with Customer [Abstract]
Royalty income (loss)	(10)	10,910,823	5,722,317	14,483,164
Fee Royalties
Revenue from Contract with Customer [Abstract]
Royalty income (loss)	$ 1,462	$ 187,749	$ 242,403	$ 378,422