Production de houille

A dense coal, usually black, sometimes dark brown, often with well-defined bands of bright and dull material, used primarily as fuel in steam-electric power generation, with substantial quantities also used for heat and power applications in manufacturing and to make coke. Bituminous Coal is the most abundant coal in active U.S. mining regions. Its moisture content usually is less than 20 percent. The heat content of Bituminous Coal ranges from 21 to 30 million Btu per ton on a moist, mineral-matter-free basis. Production data include quantities extracted from surface and underground mines, and normally exclude wastes removed at mines or associated reparation plants.