Anthracite Geologically, the largest most concentrated anthracite deposit in the world is found in the Lackawanna Coal Mine in northeastern Pennsylvania, United States in and around Scranton, Pennsylvania. Locally called the Coal Region, the deposit contains 480 square miles of coal bearing rock which originally held 22.8 billion short tons (20.68 billion tonnes) of anthracite. (The geographic region is roughly 100 miles (161 km) in length and 30 miles (48 km) in width.) Because of historical mining and development of the lands overlying the coal, it is estimated that 7 billion short tons (6.3 billion tonnes) of minable reserves remain. The
Anthracite difficulty of igniting it. This was a particular concern in smelting iron using a blast furnace. With the invention of hot blast in 1828, which used waste heat to preheat combustion air, anthracite became a preferred fuel, accounting for 45% of US pig iron production within 15 years. Anthracite for iron smelting was later displaced by coke. From the late 19th century until the 1950s, anthracite was the most popular fuel for heating homes and other buildings in the northern US, until it was supplanted by oil-burning systems and more recently natural gas systems. Many large public buildings, such as