Classifying Coal Mixtures

摘要

The Russian coal industry is an important supplier of fuel and raw materials. Each customer requires coal of specific composition and properties. Classification of coal in terms of its grade composition is essential for reliable evaluation of the properties and best applications of particular coal. According to the classification employed in Russia and the Commonwealth of Independent States (All-Union State Standard GOST 25543-88), the grade of coal characterizes materials with similar technological and energy characteristics, i.e., with identical or almost identical behavior in particular conditions. This, in turn, is associated with common genetic and structural characteristics: the degree of coalication (metamorphism), in terms of the reflection coefficient of vitrinite R_(o.r) ( percent); the maceral (petrographic) composition, estimated by the content of fusinizing components SIGMA LC ( percent); the degree of reduction, characterized by the yield of volatiles V~(daf) ( percent) and the sintering properties (the plastic-layer thickness y or the Rogh index RI).