The results are presented concerning the analysis of literature sources on the issues of changes over time of coal seams methane content under the influence of rock pressure in the conditions of the second working at the mining extracted areas of methane-rich coal mines, including when unloading of the coal mass from the rock pressure and the movement of coal beaten in the face along the scraper and belt conveyors. With that, the influence was evaluated concerning the performance of the shearer on the intensity of methane emission from the broken coal, its physical and mechanical properties, the level of metamorphism and the time of coal stay on the vehicles. Mining conditions of the underground coal production, the limits of the daily productivity of the working faces, coal seams methane content, the level of coal metamorphism, and the limits of the residual methane content of coal beaten in the coal face, which is a normative parameter in the forecast of methane abundance of coal faces and degassing of methane-bearing coal seams, are given in the article. The method for studying the amount of methane in the beaten coal and the level of its natural degassing is based on natural, physical, technical, and gas factors as applied to coal seams of varying levels of metamorphism, natural methane content of the coal seams, and the level of beaten coal natural degassing. The dependences are established related to the changes in the volume of methane content in the beaten coal from the time of its stay on the lava and site conveyors, the methane content of coal in the extraction zone by the shearer and its technical productivity on the destruction of the coal mass affecting the rate of methane emission from the beaten coal in the lava within the working area. Quantitative indicators concerning coal beaten in the mine face are proposed as basic data for identification of the methane abundance of the working face, and the parameters of natural degassing of the beaten coal when developing recommendations on the parameters of degassing of the developed coal seams by the underground wells.
Read in №11 of 2019 year "Methane Emission from the Broken-down Coal in the Working Face"
25 ноя 2019