Prediction Of Spontaneous Combustion Of 7₂ Coal Seam In Yuandian No.2 Mine And Study On The Range Of Spontaneous Combustion "Three Zones" Of Goaf

This paper studies the spontaneous combustion of 7₂ coal seam in Yuandian No.2coal mine,and analyzes the unfavorable factors of fire prevention in the test face.The spontaneous combustion of coal seriously threatens the safe production of mines.Therefore,before the spontaneous combustion of coal in the goaf,it is important and realistic to grasp the parameters of spontaneous combustion of coal and to do the early prediction and prediction of spontaneous combustion of coal,and to study the scope of spontaneous combustion of the“three zones”in the goaf of the working face.Firstly,starting from theoretical research,the coal spontaneous combustion mechanism,coal spontaneous combustion prediction and forecasting technology,coal spontaneous combustion hazardous area division and the numerical simulation of goaf are understood and mastered.Secondly,through the determination of the basic parameters of spontaneous combustion of 7₂ coal seam,the main coal quality indicators were mastered,and the self-ignition tendency level was determined as class II.The oxygen consumption rate,CO and CO₂ production rate and exothermic intensity of coal samples were determined by temperature programmed oxidation experiments.And the apparent activation energy is measured;by analyzing the volume fraction of the gas produced in the coal sample experiment,the Grignard fire coefficient,the alkane ratio and the olefin ratio etc.The law of the oxidation of the coal sample divide and give the critical temperature into each stage,and combined with the principle of predicting the index of spontaneous combustion of coal,it is preferred to predict the spontaneous combustion of coal by using the marker gas and auxiliary index parameters,and to fit the functional relationship between the gas concentration and the parameter as a function of temperature,and established a multi-parameter early warning indicator system,and the coal spontaneous combustion risk was classified and early warning.Finally,through the combination of field test and numerical simulation of goaf in the working face,the results of the measured results combined with the numerical simulation range of the 7₂15 working face in the goaf is mainly concentrated in the 0 to 30 m area of the air leakage intensity of the goaf are comprehensively determined to determine the range of the“three zones”of the spontaneous combustion in the goaf,and the goaf on the inlet and return sides is obtained.The zone oxidation zone ranges from35 to 80 m and 20 to 77 m,respectively,and the minimum safe propulsion speed is calculated to be 1.76 m/d.According to the numerical simulation results,the air leakage of the air inlet side,and the air leakage speed is the largest;the larger the air supply volume of the fully mechanized mining face,the larger the air leakage to the goaf,resulting in mining The wider the width of the oxidized zone in the void,the further the distance from the working face.The obtained research results provide scientific parameters for the prevention and control of spontaneous combustion of 7₂ coal seam,and provide reference for similar coal mine safety production.Figure[36]table[30]reference[86]...