Coal assay Coal assay Coal analysis techniques are specific analytical methods designed to measure the particular physical and chemical properties of coals. These methods are used primarily to determine the suitability of coal for coking, power generation or for iron ore smelting in the manufacture of steel. Coal comes in four main types or ranks: lignite or brown coal, bituminous coal or black coal, anthracite and graphite. Each type of coal has a certain set of physical parameters which are mostly controlled by moisture, volatile content (in terms of aliphatic or aromatic hydrocarbons) and carbon content. Moisture is an important property of
Pittsburgh coal seam that was piled with coke inside iron furnaces. It has a high proportion of carbon, which accelerates combustion, and a low proportion of impurities, including ash and moisture, which retards combustion. Pittsburgh coal also has a low proportion of sulfur, which is critical to making high-quality iron. In addition, the Pittsburgh seam was located close to Pittsburgh, then the center of the growing American iron and steel industry. Coke had to be transported by water or rail to iron furnaces, and the Pittsburgh seam's proximity to iron furnaces gave the bed another competitive advantage over more distant coal seams that