ASSESSMENT OF FORECAST ACCURACY DANGEROUS PROPERTIES OF COAL LAYERS BY THE DEGREE OF METAMORPHISM OF SOLID FOSSIL COALS

In the normative base of Ukraine for the safe mining of coal seams, only five indicators of the degree of metamorphism are used to predict the manifestation of their hazardous properties during mining operations: mass release of volatile substances during thermal decomposition of coal without air (Vdaf) access to characterize coal; volumetric yield of volatile substances daf V V to establish the distinctive properties of anthracites; logarithm of electrical resistivity (lg); the thickness of the plastic layer (y) and the grade of coal (M) for predicting the outburst hazard of seams. When developing regulatory documents, it was assumed that these criteria for assessing the degree of coal metamorphism remain constant within one mine field. Their values, as mining operations show, are influenced by the location of the coal sampling site in relation to the distance from relatively large geological disturbances or the boundaries of the gas weathering zone. In most cases, the boundaries of mine fields are usually relatively large geological faults. The proximity of the locations of coal sampling points to them influences the obtained results of evaluating the properties of mine layers. Аdjusting indicators (Vdaf, daf V V , lg, y ,M) for individual mines on the possible impact of geological disturbances, the depth of the mining robot and the distance from the zone of gas weathering, according to the requirements of regulatory documents. For this reason, it is of scientific and practical interest to establish the possible ranges of change in the indicators of the degree of metamorphism of coal within the same mine layer. The results of research in this direction are relevant, as they are necessary to improve the regulatory framework for the safe mining of coal mines. A possible change within a separate mine field was considered using the example of the indicator Vdaf as the most studied at present. According to a specially developed methodology, the analysis involved data on 2193 mines from different coal basins. Most of them belong to the mines of the Donetsk basin (1773). The rest of the basins account for information on 460 mine layers, including data on 46 mine layers for the Lvov-Volyn basin.