Coal Density

the amount of coal per unit of coal-bearing area for a coal deposit, coal region, or coalfield. To determine the coal density, the amount of coal, calculated to some definite depth that is promising for development, is divided by the total area over which the coal reserves have been calculated. The result is usually expressed in millions of tons per square kilometer. Coal density is used to compute probable coal reserves, the values of relevant indexes being carried over from well-explored areas to little-studied ones, and to make comparative descriptions of the economic importance of investigated coal-bearing areas.