Note 14 - Segmented Information - Long-term Assets by Geographic Segments (Details) - USD ($)	Jan. 31, 2019	Jul. 31, 2018	Jan. 31, 2018	Jul. 31, 2017
Mineral Rights and Properties	$ 63,763,109	$ 71,122,576
Property, Plant and Equipment	7,083,431	7,101,552
Restricted cash	1,804,328	1,789,899	$ 1,779,182	$ 1,706,028
Equity-Accounted Investment	10,091,608	693,502
Other Long-Term Assets	379,279	563,052
Total Long-Term Assets	83,121,755	81,270,581
United States Texas [Member]
Mineral Rights and Properties	12,708,919	12,729,697
Property, Plant and Equipment	6,359,909	6,362,608
Restricted cash	1,715,355	1,700,926
Equity-Accounted Investment
Other Long-Term Assets	291,612	416,519
Total Long-Term Assets	21,075,795	21,209,750
United States Arizona [Member]
Mineral Rights and Properties	4,377,477	11,069,018
Property, Plant and Equipment
Restricted cash	15,000	15,000
Equity-Accounted Investment
Other Long-Term Assets
Total Long-Term Assets	4,392,477	11,084,018
United States Wyoming [Member]
Mineral Rights and Properties	31,527,870	31,527,870
Property, Plant and Equipment	349,953	357,392
Restricted cash	73,973	73,973
Equity-Accounted Investment
Other Long-Term Assets	87,667	146,533
Total Long-Term Assets	32,039,463	32,105,768
United States Other States [Member]
Mineral Rights and Properties	88,320	735,468
Property, Plant and Equipment
Restricted cash
Equity-Accounted Investment
Other Long-Term Assets
Total Long-Term Assets	88,320	735,468
CANADA
Mineral Rights and Properties	546,938	546,938
Property, Plant and Equipment	19,402	25,889
Restricted cash
Equity-Accounted Investment	10,091,608	693,502
Other Long-Term Assets
Total Long-Term Assets	10,657,948	1,266,329
PARAGUAY
Mineral Rights and Properties	14,513,585	14,513,585
Property, Plant and Equipment	354,167	355,663
Restricted cash
Equity-Accounted Investment
Other Long-Term Assets
Total Long-Term Assets	$ 14,867,752	$ 14,869,248