Distribution Law of Coal Spontaneous Combustion Hazard Area in Composite Goaf of Shallow Buried Close Distance Coal Seam Group

Abstract

ABSTRACT The spontaneous combustion of residual coal in compound goaf formed by shallow and close coal seam mining is one of the difficulties in mine fire prevention and control. In order to explore the mechanism of spontaneous combustion of residual coal in 22304 working face of Huojitu minefield in Daliuta coal mine, the causes of spontaneous combustion of residual coal in 22304 working face are studied by comprehensively applying the methods of experiment, numerical calculation, and field measurement, the limit parameters of spontaneous combustion of 22304 working face are obtained, and the risk of spontaneous combustion in 22304 working faces is divided. The results show that the critical oxygen concentration of coal in 22304 face is 8%, and the width of inlet airside and return airside of oxidation temperature rise zone in composite goaf is 245 m and 170 m. When the advancing speed of 22304 working face is greater than 7.42 m/d, it can effectively avoid spontaneous combustion in goaf. Finally, the fire prevention and extinguishing measures of composite goaf after temporary shutdown when the working face passes through faults and other geological structures are discussed. The findings have certain reference significance for the division of goaf spontaneous combustion risk areas and the formulation of fire prevention and extinguishing schemes under similar conditions.