CLAY MINERALS IN LOW-TEMPERATURE LIGNITE ASH

Abstract

The use of lignite as a fuel in power plants, as well as in the making of briquettes, coke, gas, tars and distillation products, is constantly increasing. In 1982 world production of lignite was 1200 million metric tons, of which 250 million were from East Germany. The intensive use of lignite calls for complete knowledge of its composition, especially of the inorganic components, which in part are discharged into the air as pollutants (for example, sulfur), or affect chemical and technological processes (for example, clay minerals). In addition, even the residues of combustion of the coal are used directly as additives to cement, and so forth. For all these reasons, it is necessary to known the composition of the inorganic components of the coal and its content of primary minerals. This work presents results of mineralogical investigations of the ash produced by low-temperature combustion of lignite, in which special attention was paid to the clay minerals. The coals investigated were from deposits in East Germany, the USSR, Czechoslovakia, Poland, Hungary, Bulgaria and Mongolia.