INCOME TAXES Components of Deferred Tax Assets and Liabilities (Details) - USD ($)	Jul. 31, 2019	Jul. 31, 2018
Deferred Tax Asset
Depreciation	$ 0	$ 0
Deferred compensation	2,121,000	2,057,000
Postretirement benefits	6,100,000	4,164,000
Allowance for doubtful accounts	81,000	118,000
Deferred marketing expenses	0	0
Other assets	390,000	374,000
Accrued expenses	2,076,000	2,131,000
Tax credits	250,000	683,000
Amortization	166,000	200,000
Inventories	264,000	570,000
Depletion	0	0
Stock-based compensation	556,000	367,000
Reclamation	392,000	309,000
Other assets - foreign	585,000	755,000
Valuation allowance	(732,000)	(789,000)
Total deferred tax assets	12,249,000	10,939,000
Deferred Tax Liability
Depreciation	3,995,000	3,284,000
Deferred compensation	0	0
Postretirement benefits	0	0
Allowance for doubtful accounts	0	0
Deferred marketing expenses	326,000	13,000
Other liabilities	0	0
Accrued expenses	0	0
Tax credits	0	0
Amortization	0	0
Inventories	0	0
Depletion	173,000	293,000
Stock-based compensation	0	0
Reclamation	0	0
Other assets - foreign	0	0
Valuation allowance	0	0
Total deferred tax liabilities	$ 4,494,000	$ 3,590,000