Zawartość chloru w węglach kamiennych Górnośląskiego Zagłębia Węglowego

Abstract

Zawartość chloru całkowitego w 818 próbkach węgli z 19 otworów wiertniczych waha się od 63 do 18 871 g/t (w przeliczeniu na zawartość w węglu suchym). Stwierdzono zróżnicowanie regionalne oraz stratyfikację pionową tego pierwiastka. Podobne zmienności zaobserwowano w zawartościach chlorków w wyciągach wodnych z piaskowców pochodzących z analogicznych odcinków profilu karbonu, co świadczy o związku zawartości chloru w węglach z zasoleniem górotworu. Na wyraźne obniżenie ilości chloru w węglach najgłębiej zalegających wpływa również wysoki stopień uwęglenia.CONTENT OF CHLORINE IN COALS OF THE UPPER SILESIAN COAL BASIN The paper presents results of estimations of total chlorine content in 818 samples of coals from 19 boreholes (Fig. 1). Fourteen of these boreholes penetrated the whole section of the coal-bearing Carboniferous, and the remaining five - rocks of the Mudstone Series and Upper Silesian Sandstone Series. The range of variability of total chlorine content in the studied samples appears very wide: from 63 to 18.871 g/t (values converted to content in dry coal) - Table 1. The studies also showed some regional variability in content of chlorine. Coals from boreholes situated in central and southern parts of the studied area yield chlorine in amounts from 900 to 1,700 g/t, whereas those from SW part appear characterized by lower contents and those from E and SE part - higher contents of that element. The variability in content of chlorine in coals appears generally similar to that of chlorides in water extracts from sandstones from the same parts of borehole sections (Table 3). A vertical stratification in content of chlorine in coals was also found (Fig. 2). In northern part of the studied area, where thickness of permeable cover rocks is small, the content is low in coals from the uppermost part of the Carboniferous section to increase to the highest values in coals occurring somewhat below and gradually decrease downwards along with depth. In borehole columns from southern part of the area, where cover rocks are thicker, the content of chlorine does not decrease but is the highest in coals from top part of the Carboniferous to decrease downwards along with depth. Coals from E and SE parts of the studied area, characterized by the highest content of chlorine, display similar stratification as those from the northern part. The marked decrease in content of chlorine in the deepest-seated coals is due to a general decrease in salinity of rock massif as well as high degree of their coalification.