The evaluation of threats connected with the presence of methane in coal seams is based on our
knowledge of the total content of this gas in coal. The most important parameter determining the potential
of coal seams to accumulate methane is the sorption capacity of coal a. It is heavily influenced by the
degree of coalification of the coal substance, determined by the vitrinite reflectance R0 or the content of
volatile matter V daf. The relationship between the degree of coalification and the sorption capacity in the
area of the Upper Silesian Coal Basin (USCB) has not been thoroughly investigated, which is due to the
zonation of methane accumulation in this area and the considerable changeability of methane content in
various localities of the Basin. Understanding this relationship call for in-depth investigation, especially
since it depends on the analyzed reflectance range. The present work attempts to explain the reasons for
which the sorption capacity changes along with the degree of coalification in the area of Jastrzębie (the
Zofiówka Monocline). The relationship between parameters R0 and V daf was investigated. The authors
also analyzed changes of the maceral composition, real density and the micropore volume. Furthermore,
coalification-dependent changes in the sorption capacity of the investigated coal seams were identified.
The conducted analyses have indicated a significant role of petrographic factors in relation to the accumulation
properties of the seams located in the investigated area of USCB.
Studies on the quality of bituminous coal are mainly focused on physico-chemical analysis, examining the ash content, sulphur content, volatile matter content, moisture content, and the Net Calorific Value of coal. Until now, the above mentioned parameters form the basis of the Polish Standard PN-82/87002, on the basis of which individual types of bituminous coal are determined. In addition, an elemental analysis, providing information about the content of primary elements in the organic matter of solids, i.e. coal, hydrogen, nitrogen, oxygen, and sulphur, is carried out for the selected samples. This issue has been studied by many authors, which undoubtedly provide invaluable knowledge due to the huge amount of data, but, as the authors themselves indicate, the knowledge of the petrography of coal, coking properties (Probierz et al. 2012) and finally the coke obtained from individual coal types (based on tests carried out using the Karbotest installation or the so-called „box tests” performed in the coke oven battery) is still very limited. The article discusses the impact of petrographic composition on the quality of metallurgical coke. The analysis was performed using samples of coking coal from the following mines: Pniówek, Zofiówka, Borynia, and Krupiński. The mentioned coal types are used to produce coke mixtures used for the production of coke in the Przyjaźń and Radlin coking plants. Based on the rank of coal and physicochemical parameters, the mentioned coal types were classified according to the Polish classification and the UN/ECE International Classification of In-Seam Coals (UN/ECE 1995). The prediction of thermomechanical properties of coke (CSR and CRI) performed according to the original CCP method were compared with the results obtained using the classical method of Nippon Steel Corporation.
Raman spectroscopy and vitrinite reflectance measurements of dispersed organic matter from Carboniferous shales in boreholes in the northern part of the Intra-Sudetic Basin were used for thermal history reconstruction. Microscopic investigations have shown that the organic matter is dominated by the vitrinite maceral group. In analysed samples, organic matter shows a varied degree of thermal alteration determined by the mean random vitrinite reflectance (VRo) ranging from 0.72% to 3.80%. Mean apparent maximum vitrinite reflectance (R’max) values reached 4.98%. The full width at half maximum of D1 and G bands in Raman spectra are well-correlated with mean VRo and R’max. Thermal maturity in the boreholes shows a regular increase with depth. Geological data combined with Raman spectroscopy and mean vitrinite reflectance results indicate that the analysed Carboniferous strata reached maximum paleotemperatures from c. 110 to c. 265°C. The regional paleogeothermal gradient in the late Paleozoic was c. 80°C/km. The Variscan heating event presumably caused a major coalification process of organic matter. The Carboniferous–Permian magmatic activity must have contributed to high heat flow, adding to the effect of sedimentary burial on the thermal maturity.