Anthracite coal, also known as hard coal, is a naturally occurring carbonaceous material that represents the highest level of non-metamorphic coalification. Anthracite coal forms when the geologically preserved organic residue of primordial swamps is compressed and re-worked by the earths crust. The result is a low ash, low volatile, homogenous coal with a high BTU content. Anthracite coal is used in products and processes where non conductive, low cost, black mineral filler is required.
AC can also be used in foundries as a carbon raiser, refractory coating component, or other hot metal application. It performs well as filler in rubber compounds and as a pigment.