Distribution Of "Three Zones" Of Spontaneous Combustion In Ji ₁₅-31060 Goaf Of Pingmei No.4 Coal Mine

Spontaneous combustion in goaf is one of the major disasters in coal mines,the development of scientific and reasonable measures to prevent and control spontaneous combustion in the mining area is extremely important to the safe production of coal mines,and the key to prevent and control spontaneous combustion in the mining area determines the distribution of spontaneous combustion in the mining area"three zones".This paper uses experimental studies,field observations,numerical simulations and theoretical analysis to study,the distribution of spontaneous combustion’three zones’in goaf of Ji.₁₅-31060 fully mechanized mining face in No.4 Coal Mine of Pingmei and the prevention and control technology of spontaneous combustion fire were studied.Temperature programmed oxidation of coal samples from Ji ₁₅-31060 in No.4Pingdingshan Coal Mine the variation pattern of the concentration of carbon-oxygen,hydrocarbon and oxygen gases was analyzed,effect of temperature on the rate of oxygen consumption,CO and C₂H₄ were identified as landmark gases for the prediction of coal spontaneous combustion.Two bundle pipes are arranged in each of the return and inlet lane of Ji ₁₅-31060,and the oxygen concentration index to divide the mining area spontaneous combustion"three zones"range,The minimum natural ignition period of Ji₁₅ coal seam is 80.24 days determined by using coal spontaneous combustion ignition test Based on the measured width of the oxidation zone and the shortest natural fire period,the safe working face recovery rate to prevent spontaneous coal combustion fires in the mining area was determined to be 0.62m/d（18.6m/month）.Using Comsol numerical simulation software,simulating the range of spontaneous combustion’three zones’in goaf of Ji ₁₅-31060 in No.4 Coal Mine of Pingmei and compare it with the actual field measurement range,validated the accuracy of Comsol simulation.Simulated the range and changes of"three zones"of spontaneous combustion in the mining area at different wind speeds at the working face,the results show that the greater the wind speed at the working face,the greater the width of the oxide zone in the mining area.According to the above research results,the prevention and control of spontaneous combustion fire at the working face of Ji ₁₅-31060 is proposed to prevent and control spontaneous combustion in the mining area by nitrogen injection and leakage prevention and fire suppression.