Title: Basic Factors Controlling Coal Quality and Technological Behavior of Coal
Abstract: Publisher Summary Coal is used in processes such as combustion, gasification, and liquefaction and in carbonization for the manufacture of metallurgical coke. Coal and its derivative products are also used as precursors of other materials and in the production of chemicals. There are two characteristics that influence the use of coal: its composition and its rank. Coal composition is, in turn, represented by two essentially independent factors: type and grade. Coal is a heterogeneous material, and evaluation of coal type may be approached on two different levels: the macroscopical and microscopical, both of which form a part of coal petrology. The chapter also details the coal metamorphism, which involves the physical and chemical transformation from peat through bituminous coal through anthracite and meta-anthracite to graphite. It is a function of heat and pressure acting over a period of time. It is also denoted as the coal rank, which is marked by a progressive decrease in moisture and volatile functional groups with a consequent increase in the carbon content of the coal.