GERMANIUM RELATIONSHIP WITH ASH AND “TOXIC” ELEMENTS IN COAL ON THE EXAMPLE OF SEAM C5 OF THE BLAHODATNA MINE FIELD OF WESTERN DONBAS
Authors:   Institute of Geotechnical Mechanics named by M.S. Polіakov of National Academy of Sciences of Ukraine, Ishkov Valerii , Kozii Yevhen ,   Dnipro State Agrarian and Economic University, Kozar Mykola ,   Institute of Geochemistry, Mineralogy and Ore Formation of the NAS of Ukraine, Pashchenko Pavlo ,   Institute of Geotechnical Mechanics named by M.S. Polіakov of National Academy of Sciences of Ukraine, Dreshpak Oleksandr ,   Dnipro University of Technology
Published: February 2024

Purpose. The character and level of the statistical relationship between the content of germanium and “toxic elements” in coal seam c5 of the “Blahodatna” mine and the main features of their distribution were established for the assessment of possible environmental risks during the selective processing of coal enriched with this element. It has been proven that the correlation between germanium and all “toxic” elements is inverse and very weak. The existence of genetically different forms of germanium and arsenic, fluorine, mercury and beryllium was revealed. Methods. The research materials included analysis of 38 coal samples for germanium, beryllium, fluorine, mercury and arsenic, performed in accredited state laboratories after 1981. The content of germanium, beryllium and fluorine was determined by quantitative emission spectral analysis, mercury and arsenic – by atomic absorption analysis. The samples were taken during the work of production enterprises and research organizations with the participation of the authors, using the furrow method of sampling in mine workings and from the core of wells from 1981 to 2018. For primary processing of geochemical data, STATISTICA 13.3 and IBM SPSS Statistics 22 were used to calculate basic statistical characteristics, including mean, standard error of the mean, median, kurtosis, mode, standard deviation, variance, minimum and maximum values, coefficient of variation, and sample skewness . Frequency histograms were created for visual assessment of the studied parameters, as well as the characteristics of their distribution were determined. To achieve the objectives of the study, correlation and regression analyzes were carried out using the functions available in Micromine – the leading professional mining and geological information system for 3D modeling, statistical data processing and mining planning. Results. It was established that a general feature of the distribution of ash content, germanium, arsenic, fluorine, mercury and beryllium in the c5 coal seam of the Blahodatna mine field is their non-compliance with normal and lognormal laws and the polymodality of the distributions with a shift of the density nuclei to the left, except for beryllium and germanium. Each of the studied elements in seam c5 of the “Blahodatna” mine accumulated in several forms, which differed significantly in their genesis. At the same time, the forms of finding, which are responsible for the minimum contents, were jointly accumulated at the initial, syngenetic stage. The presence of an inverse and very weak correlation between germanium concentrations and ash content, arsenic, fluorine, and mercury contents in the c5 coal seam of the Blahodatna mine was revealed. The only element considered that forms a very weak positive correlation with germanium is beryllium. Scientific novelty of the results. The presence of genetically different forms of germanium and arsenic, fluorine, mercury and beryllium in coal seam c5 of the Blahodatna mine was revealed. The polymodality of the distributions was established for all the considered components, while the displacement of the density of their distribution to the left was proved, except for germanium and beryllium. It has been proven that the correlation between germanium and ash content and all “toxic” elements (except beryllium) is inverse and very weak. Practical significance of the results. Justification of the method of the most accurate assessment of the central tendency in the distribution of a sample population of concentrations of germanium and arsenic, fluorine, mercury and beryllium in coal seam c5 of the “Blahodatna” mine. The presence of a very weak correlation between the content of germanium and “toxic” elements makes it possible to predict the minimal nature of possible environmental risks during the selective processing of germanium-enriched coal.