Abstract:
The phenomenon of spontaneous combustion of coal left in the goaf directly affects the safe and efficient mining of coal mines, and the use of plugging materials to close the air leakage channel is an effective method to solve the problem of spontaneous combustion of coal in the goaf. Taking the F1301 re-mining face of Yunhe Coal Mine as the engineering background, aiming at the hidden danger of spontaneous combustion of loose coal left in the tunneling roadway in the goaf, the implementation scheme of gel plugging and fire extinguishing technology for loose coal was formulated. The COMSOL numerical simulation method was used to study the gel diffusion law under different injection time and pressures, and the engineering application was carried out. The results show that the injection time and pressure are proportional to the gel diffusion range. Considering the injection effect and cost, 10 MPa and 140-160 min are selected as the best injection pressure and time, and the distance between the injection holes is set to 5 m. After the implementation of the gel plugging fire prevention and extinguishing scheme, the monitoring data of the observation boreholes on both sides of the roadway show that the volume fraction of the iconic gas CO is stable below 24×10
−6, and the gel plugging fire prevention and extinguishing effect is good, which effectively eliminates the hidden danger of spontaneous combustion of coal left in the goaf.