Disturbance of high-level gas extraction roadway configuration on coal spontaneous combustion

CHEN Liang; YU Hongyang; BI Xiongfei; XU Zhenwei; WANG Dongwei; QIN Ruichen; GUO Lei

doi:10.11799/ce202505011

Abstract：To address the unclear disturbance effects of high-level extraction roadways on coal spontaneous combustion in goaf areas of fully mechanized top-coal caving faces within self-igniting seams,we investigated the No.150315 working face with a four four roadways at Yinying Mine,Shanxi Province.We employed a hybrid methodology integrating theoretical modeling,UDEC simulations,and Image-Pro image analysis to quantify fracture zonation characteristics and derive porosity distribution functions in overburden strata.Preliminary gas extraction optimization suggested an optimal vertical height range of 20～53 m for high-level extraction roadways.Using Comsol software,we simulated and analyzed the distribution and width evolution of gas concentration in goaf under high extraction roadway disturbance at different locations,as well as the quantitative variation characteristics of gas concentration and oxygen concentration under different extraction negative pressures.It was pointed out that the horizontal distance was positively correlated with its disturbance effect on the oxidation rising temperature zone,and its vertical height was proportional to the extraction gas concentration and inversely proportional to the vertical oxygen concentration.It was determined that:the high extraction roadway was 20 meters horizontally away from the return airway,50 meters away vertically from the coal seam roof,and its reasonable extraction negative pressure was 20 kPa.The on-site engineering tests demonstrated that,after optimization of the high extraction roadway,the extraction volume was 1.37 m3/min less,and the gas concentration in the working face return airway was only 0.04 percentage points higher,which were both within the safe range.Meanwhile,the width of the heat dissipation zone and the spontaneous combustion oxidation zone in the goaf was 12 m and 9 m narrower,respectively.The optimization effectively brought down the risk of spontaneous combustion,and contributed to the synergistic co-governance of gas and coal spontaneous combustion disasters in the goaf.