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.
The aim of this paper is an analysis of the variability of the methane content in coal seams in the area of the Dębieńsko Mine and it’s relation to the geological structure of this coal deposit, and also the possibilities of a methane hazard in the areas of future coal mining and methane utilization as a fuel. The Dębieńsko coal deposit is located in the western part of the Upper Silesian Coal Basin (USCB), on the boundary between folded and disjunctive tectonic zones. Coal exploitation in this area ended in 2000, but interest in this deposit is currently high due to plans to initiate coking coal mining. The area of the Dębieńsko mine is relatively well prospected because of the deep drillings (up to 2000 m in depth) carried out within it. The methane conditions of the deposit are varied, the methane content increases with depth according to northern pattern of methane distribution in the USCB, in which the high-methane zone occurs under the several hundred meters zone of natural outgassing of the coal seams. This zone is divided into two smaller methane sub-zones, the first (shallower) at a depth of 1000 m and the second (deeper) at 1700–1900 m. A sub-zone of lower methane content occurs between these two high-methane sub-zones. The most important reasons for this methane distribution are temperature and pressure facilitating the gas adsorption in coal seams, and also the presence of impermeable siltstones and shalestones as well as the maceral composition and coal rank of coal seams. The methane content also changes laterally in accordance with the tectonics of the area. The so called Knurów and Leszczyna Anticline with found increased methane content in coal seams in relation to neighboring areas as well as Orlova Overthrust together with the system of latitudinal faults of brittle tectonic regime which are possible pathways for methane migration play a special role here. These structures can be taken into account as a potential source of methane hazard in a future coal mine, they can also be promising structures for methane prospection as a fuel.
The paper presents the correlation between the CRI (Coke Reactivity Index), CSR (Coke Strength after Reaction) and the remaining 36 quality parameters of coking coal from the Pniówek deposit (SW part of the USCB). The test results were obtained for a region of fundamental importance to the Polish reserves of coking coal, characterized by highly variable coalification and quality parameters. The tests related to the determination of relationships of the CRI and CSR indices to other parameters were based on 25 channel samples acquired from active workings. The characteristics of the variability of the CRI and CSR indices were analyzed using statistical methods. The dependencies between the CRI and CSR indices and the parameters having an impact on their values were determined using linear correlation. An attempt was also made to determine the correlations between the concerned parameters using the multiple correlation method. The obtained results have been presented and compared to the results of globally conducted experiments in the form of charts presented by (North et al. 2018b). No clear dependence of the CRI and CSR indices was exhibited in case of most of the analyzed quality parameters, which is supported by low correlation coefficients of r < 0.5. The statistical analysis exhibited only 9 cases of correlation between CRI and CSR with other quality parameters, where the correlation coefficient was r ≥ 0.5, that is: Ht a, Na2O, Al2O3 and SiO2, Mn3O4, da a and dr a. This confirms the different characteristics of coal from the studied area, exhibited multiple times, that should be related to the specific coalification process, especially the occurrence of thermal metamorphism.
The purpose of the research was mapping, inventorization, and valorization of coal mining waste dumps from the mines of JSW SA company, for the needs of recovery of coal from the dump material as well as the reclamation and management of examined facilities. The valorization of post-mining waste dumps has been carried out using a methodology which considers the problems of reclamation, management, accessibility of the dumps as well as environmental hazards connected with disposing of mining and preparation wastes on the ground surface. An inventorization of 10 coal mining waste dumps coming from 6 mines of JSW SA including in their range 7 deposits: Borynia, Jastrzębie, Zofiówka, Budryk, Knurów, Szczygłowice and Pniówek was carried out. The source material within the localization of particular dumps was obtained from archival materials coming from coal mines and municipalities where the dumps are located. Verified data has been drawn on topographical map, which results in the map of coal mining waste dumps. The results of the valorization of the dumps comprise the defining of: the name of the dump, state of the dump, surface of the dump, accessibility, name of the coal mine from where the wastes come from, type of technical and biological reclamation and possibilities of coal recovery, which have been brought on the drawn map. Basing on collected and elaborated data, an attempt of defining of potential possibilities of recovery of coal from the dumps and connection of coal quality in the deposits of JSW SA and in waste material was made. The results of the research showed that in spite of preliminary information that a majority of the investigated dumps may be considered as potential facilities for coal recovery, ultimately the recovery is economically justified only in several cases (5 facilities).
The solutions presented permit the practical determination of the physical parameters of peak ground vibration, caused by strong mining tremors induced by mining, in the Polish part of the Upper Silesian Coal Basin (USCB). The parameters of peak ground horizontal velocity (PGVH) and peak ground horizontal acceleration (PGAH10) at any point of earth’s surface depend on seismic energy, epicentral distance and site effect. Distribution maps of PGVH and of PGAH10 parameters were charted for the period 2010-2019. Analysis of the results obtained indicates the occurrence of zones with increased values of these parameters. Based on the Mining Seismic Instrumental Intensity Scale (MSIIS-15), which is used to assess the degree of vibration intensity caused by seismic events induced by mining, and using the PGVH parameter, it was noted that the distribution map of this parameter includes zones where there vibration velocities of both 0.04 m/s and 0.06 m/s were exceeded. Vibrations with this level of PGVH correspond to intensities in the V and VI degree according to the MSIIS-2015 scale, which means that they can already cause slight structural damage to building objects and cause equipment to fall over. Moreover, the reason why the second parameter PGAH10 is less useful for the evaluation of the intensity of mining induced vibrations is explained. The PGAH10 vibration acceleration parameter, in turn, can be used to design construction of the objects in the seismic area of the Upper Silesian Coal Basin, where the highest acceleration reached a value of 2.8 m/s2 in the period from 2010 to 2019.
The Neogene basaltoid intrusions found in the S-7 borehole in the Sumina area (USCB) caused transformations of the adjacent Carboniferous rocks. The mineral and chemical compositions of the basaltoides are similar to those of the Lower Silesian basaltoides. The transformations that took place in the vicinity of the intrusion were manifested in the formation of natural coke, the secondary mineralization of these rocks (calcite, chlorite, zeolites and barite) and in the specific distribution of rare earths (REY). Among REY, the light elements (LREY) had the highest share, while the heavy elements (HREY) had the lowest share. Regardless of the lithological type of the analyzed rock, with increasing distance from the intrusion, the percentage of MREY and HREY elements increases at the expense of the light elements LREY. All analyzed distribution patterns of the REYs are characterized by the occurrence of anomalies, which often show a significant correlation with the distance of sampling points from the basaltoid intrusion. The specific distribution of REYs in the vicinity of the intrusion of igneous rocks is an indication of the impact of hydrothermal solutions associated with the presence of basaltoides on the rocks closest to them located at a temperature of over 200°C.