Study on spontaneous combustion characteristics and fire prevention technology in the fully mechanized top-coal caving face of Gaojiapu coal mine

Abstract To address the issue of spontaneous combustion, the spontaneous combustion propensity of the coal body and the indicator gases of spontaneous combustion in the 3406 fully mechanized top-coal caving face were determined, and the oxygen concentration and the air leakage distribution across the working face were analyzed. The COMSOL was used to spontaneous combustion “Three Zones” were precisely divided. Based on these findings, a targeted fire prevention and control scheme for the goaf area was developed. The results show that: (1) The coal seam in the working face poses a risk of spontaneous combustion. Temperature-programmed oxidation experiments on coal samples identified CO and C 2 H 4 as the indicator gases for spontaneous combustion. (2) The asphyxiation zone is distributed in the deep goaf at 230–261 m from the working face; The oxidation zone in the return-side goaf at 12–230 m and in the intake-side goaf at 70–261 m; The heat dissipation zone lies in the goaf within 12–70 m. The maximum width of the oxidation zone is 218 m. (3) An integrated fire prevention and control technology combining “grouting and nitrogen injection” was implemented for the goaf area. The spontaneous combustion in the goaf area was prevented.