Schedule of useful lives of assets

Depreciation of assets in mining units with short useful lives or used for administrative purposes is calculated using the straight-line method of accounting. The useful lives are the following:


		Years

Buildings, construction and other		2 to 11
Hydroelectric power station		20 to 40
Machinery and equipment		2 to 30
Transportation units		5
Furniture and fixtures		4 to 10
Other equipment		3 to 10
Computer equipment		3 to 5

Basis for preparation, consolidation and accounting policies

Schedule of estimated useful lives of right of use assets


		Years

Land		30
Buildings and other constructions		Between 1 and 14
Machinery and equipment		Between 1 and 14