How does large scale strip mining work?
Strip mining is used when the coal seam is relatively close to the surface. First the topsoil and subsoil are removed by large scrapers. The topsoil may be moved to cover previously mined areas or temporarily stockpiled. The exposed overburden, the earth that is between the topsoil and the coal seam, is leveled, drilled, and blasted. Then the overburden material is removed down to the coal seam, usually by a dragline or a shovel and truck operation. The uncovered coal seam is then drilled and blasted. The raw coal is then transported to a temporary storage area where it may be crushed and screened then moved to a loading storage area.
