History of anthracite coal mining in Pennsylvania History of anthracite coal mining in Pennsylvania There are two types of coal found in Pennsylvania: anthracite (the “hard coal” found in Northeastern Pennsylvania below the Allegheny Ridge southwest to Harrisburg; also called “stone coal”, “rock coal” in the 1800s) and bituminous (“soft coal”, found west of the Allegheny Front escarpment). Anthracite coal is a natural mineral with a high carbon and energy content that gives off light and heat (produced energy) when burned, making it useful as a fuel. It was possibly first used in Pennsylvania as a fuel in 1769, but its real history begins with a documented
Pulverized coal-fired boiler the mixture. Coal contains mineral matter which is converted to ash during combustion. The ash is removed as bottom ash and fly ash. The bottom ash is removed at the furnace bottom. This type of boiler dominates the electric power industry, providing steam to drive large turbines. Pulverized coal provides the thermal energy which produces about 50% of the world's electric supply. Prior to the developments leading to the use of pulverized coal most boilers utilized grate firing where the fuel was mechanically distributed onto a moving grate at the bottom of the firebox in a partially crushed gravel like