Study on the air leakage law and prevention and control measures in goaf of close-distance coal seam group

In view of the problem that the occurrence conditions of coal seams are complicated, the coal seam spacing is small, and the air leakage passage exists in adjacent goaf in Guizhou. SF₆ tracer method and gas data analysis method of key area index were used to study the air leakage law and prevention and control measures in goaf. The results show that due to the poor effect of adjacent sealing effect, the air leakage is serious in 31004 open-cut contact lane and 31004 working face closed air return lane. Air leakage passage in 31004 goaf is longitudinal air leakage passage formed by the close of 31004 open-cut contact lane and the secondary disturbance of 10^# coal seam to the upper 7^#coal seam goaf in the mining process; the air leakage volume is 83 m³/min, and the wind speed in goaf is about 0.17 m/s. Water injection cooling measures were adopted for the potential trouble of coal spontaneous combustion, the CO volume fraction decreased significantly to the range from 5×10^-6 to 9×10^-6. It provides scientific basis and control measures for the prevention and control of coal spontaneous combustion in 50105 working face and 50107 working face to be mined.