Dependences between certain petrographic, geochemical and technological indicators of coal quality in the limnic series of the Upper Silesian Coal Basin (USCB), Poland

Abstract

This article aims to assess the values of the most often measured petrographic, geochemical and technological indicators of coal quality and to identify probable dependences between them in the USCB coal. The following can also be observed: high content of Cd and Co in carbonate minerals separated from coal, in clay minerals – Cr and Zn, and in sulfide minerals – Cu, Ni and Pb. Nevertheless, it is organic matter which has the greatest influence on the average content of trace elements in coal. Correlations between the values of some of the indicators of coal quality were also observed. It has been observed that the increase in vitrinite content in coal is accompanied by a decrease in, while an increase in the content of liptinite and inertinite in coal is accompanied by an increase in the content of CaO, MgO, and SO3 in coal ash. An increase in the carbonization of organic matter is accompanied by an increase in the content of Cu and Ni in coal, and a decrease in the content of Pb and S in coal and the content of Fe2O3 in coal ash.