If the ore contains sulfides, the mining company covers it with a layer of clay to prevent rain and oxygen from coming into contact with it which could oxidize the sulfides producing sulfuric acid; a phenomenon known as acid mine drainage. The next step is to cover the area with soil and seed it with vegetation to help merge the materials.
Minerals and Mining By Dr Kenneth J Reid Professor Emeritus, University of Minnesota Member, Board of Directors, SME Twin Cities Sub Section Rev 2 July 2012 . Let's start on a Monday morning. Six o'clock Monday morning. Time to get up. Electricity to run the clock comes through Copper Wires. Copper comes from a Copper Mine. Copper Sulfide minerals have to be .