Rank, petrographic composition and chemical-technological properties of seam coals from the Upper Silesian Coal Basin

Rank of coal expressed by mean vitrinite reflectance differentiates the Upper Silesian coals into medium rank para-, ortho- and metabituminous coals and high rank perbituminous coals and anthracites. Seam coal coalification was caused by regional and thermal metamorphic conditions regardless to attachment of seams to certain lithostratigraphic series of Namurian and Westphalian ages. The widest coalification range (R_o = 0.75-4.97%) is typical for coals of Upper Silesian Sandstone Series, the narrowest range in turn, for coals of Krakow Sandstone Series. Coals in whole coalification range differ strongly with exinite maceral group content (0-38%) and close genetic relationship is visible between petrographic composition of coals and the lithostratigraphic series to which they belong. Chemical and technological properties of coals with similar rank depend, to some extend, on their petrographic composition. In case of orthobituminous coals certain divergence between genetic parameters (R_o) and caking properties (RI) has been ascertained. Both optical parameters (R_o) as well as chemical and technological properties of anthracites from Upper Silesian Sandstone Series conform to products of thermal metamorphism. Considerable part of coal reserves in the U.S.C.B. (about 80%) consists of para- and orthobituminous coals. Metabituminous types constitute up to 20% of coal reserves. Recognized anthracite resources create no significant number in overall balance of reserves. Increasing quantities of anthracites and metabituminous coals can be, however, predicted at bigger depths.