The Tendency of Coal Seams to Endogenous Fire Hazard and the Main Components of Coal

Purpose: to improve the regulatory framework for safe mining operations, to establish the individual influence of the elemental composition of the organic (combustible) part of fossil coals, their moisture content and sulfur content on the actual frequency of occurrence of endogenous fires during the development of individual seams of the Donetsk Basin. Methodology: The methodology involves analyzing data on coal seams divided into three groups, classified according to their susceptibility to endogenous fire hazards. This classification aligns with the standards set in the existing regulatory documents. By doing so, the research enables a systematic analysis of the key indicators for each group, ensuring that the findings are directly applicable to regulatory frameworks. The conducted studies demonstrate that reliable forecasting of the fire-hazardous properties of coal seams requires the use of indicators that directly characterize the natural composition and properties of fossil coals. Current practices, which often rely on the mass yield of volatile substances during the thermal decomposition of coals without air access, fail to provide sufficient insight into changes in elemental composition. This limits the ability to understand the role of key components. The research highlights the significant role of moisture, noting that its various forms are linked to the degree of metamorphic transformations of the coals. Furthermore, the carbon content is shown to regulate the total presence of other primary elements of the combustible (organic) mass—namely, oxygen, hydrogen, nitrogen, and sulfur. Carbon thus serves as the principal indicator of coalification and the extent of metamorphism. An important observation is that the endogenous fire hazard of coal seams is not determined by any single classification indicator. Rather, it is the result of a complex interaction between multiple factors, including elemental composition, moisture, sulfur content, and degree of metamorphic change. Interestingly, the specific impact of sulfur content on the occurrence of endogenous fires remains under-researched, pointing to the need for further targeted studies in this area. The findings from this research provide a scientific basis for improving the regulatory framework related to predicting and managing the fire hazards of coal seams during mining operations. This will ultimately contribute to safer working conditions in mines and more effective risk management practices.