SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Tables)

12 Months Ended

Dec. 31, 2019

Accounting Policies [Abstract]

Schedule of estimated useful lives of property, plant and equipment

The following table summarizes the estimated useful lives of the Company’s different classes of property, plant and equipment:

	Years
Land improvements	10 to 25
Buildings and structures	10 to 30
Leasehold and building improvements	5 to 40
Machinery and equipment – vehicles	3 to 10
Machinery and equipment – other mining and production	3 to 50
Office furniture and equipment	3 to 10
Mineral interests	20 to 99