Abstract:
In order to study the spontaneous combustion law of close distance easy spontaneous combustion coal seams, taking the mining face of Bulianta Mine No.22 coal seam 3# panel as an example, collected No.22 coal seam samples of Bulianta Mine, three particle size coal samples were selected for programmed temperature rise experiment, the paper analyzed the relationship between the gas concentration generated by coal spontaneous combustion, φ(C2H6)/φ(CH4), φ(C2H4)/φ(CH4), numerical values of R1, R2, R3 and the temperature changes of the coal samples in the experiment. According to the principle of index gases optimization, the gas concentration of CO and numerical value of R2 were selected as the main indexes for predicting and forecasting spontaneous combustion of Bulianta Mine, the gas concentration of C2H4, C2H6 and numerical value of R1 were selected as auxiliary index, the spontaneous combustion critical temperature and dry cracking temperature of Bulianta Mine samples were 60 ℃ to 75 ℃ and 100 ℃ to 120 ℃. Combining with the occurrence features of shallow depth, close distance and easy spontaneous combustion of coal seam, considering the ventilation system in mining face and the condition of mining deployment, by the use of the programmed temperature rise experiment results and theoretical research, the paper comprehensive analyzed the influence factors of spontaneous combustion of close distance goaf. The results showed that the haulage gate, air return way, starting cut and stopping line of the No.22 coal seam goaf, and the remaining coal pillar of overlying goaf were areas prone to spontaneous combustion; comprehensive prevention and control measures such as ground drilling for grouting in coal pillar area of the No.12 coal seam, fixed grouting station for grouting in goaf of the No.22 coal seam, nitrogen injection in goaf of upper and lower coal seams and nitrogen inerting and advance arrangement of working face pressure equalization emergency system are adopted to ensure safe mining of working face and further improve the mine fire warning and comprehensive prevention and control system.