Bituminous coal is the most abundant type of coal in the United States. It has a carbon content ranging from 45 to 86 percent carbon and a heat value of 10,500 to 15,500 BTUs-per-pound, much higher than lignite or sub-bituminous coal. It is used mainly to generate electricity and to make coke to manufacture steel.
Central Appalachian metallurgical (met) coal is high-grade bituminous coal (high in energy content, 12,500 btu/lb, and low impurities). Central Appalachian steam coal is generally high-grade bituminous coal as well, and some can be sold as met coal. Is is traded at the NYMEX.