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
Underground coal gasification oxidants (air, oxygen) and steam to ignite and fuel the underground combustion process. Separate production wells are used to bring the product gas to the surface. The high pressure combustion is conducted at temperature of , but it may reach up to . The process decomposes coal and generates carbon dioxide (), hydrogen (), carbon monoxide (CO), methane (). In addition, there are small quantities of various contaminants including sulfur oxides (), mono-nitrogen oxides (), and hydrogen sulfide (). As the coal face burns and the immediate area is depleted, the oxidants injected are controlled by the operator. There are