Study On Coal Spontaneous Combustion Risk In Goaf Of Rotary Mining Face

In order to better prevent the occurrence of coal spontaneous combustion in the airspace during rotary mining,the risk of coal spontaneous combustion in the airspace of rotary mining workings needs to be studied.In this paper,a combination of theoretical analysis,experimental tests,numerical simulations and field measurements was used to study the risk of coal spontaneous combustion in the rotary mining workings using the 10111 rotary mining workings in Suntong Mine of Huabei Mining Group.The results show that the air leakage depth of the mining area can reach 94m;through the field measurement of the gas composition and concentration in the mining area and the numerical simulation analysis results,the spontaneous combustion risk range of 10111 mining area is obtained,i.e.42?88m in the machine tunnel side,28-56m in the air tunnel side and 53?89m in the central part;through the determination of the thickness of the coal left behind on the By determining the risk of spontaneous combustion in the air mining area,it was determined that there is a risk of spontaneous combustion at the location where the thickness of the coal remains is higher than 0.4m;using the Kalenjin formula to calculate the shortest natural ignition time of the coal seam is about 59d,from which the minimum advance speed of the working face is 2m/d and the minimum advance angle speed is 0.01rad/d;using hierarchical analysis and fuzzy evaluation method to study the risk factors of spontaneous combustion in rotary mining working face,it is determined that the safety level of coal spontaneous combustion in the mining area is dangerous,and the propensity of coal spontaneous combustion M,leakage wind speed S,oxygen concentration Y,coal mining method C and working face advancement speed V are the main factors affecting the risk of spontaneous combustion in the mining area of rotary mining working face.The research results have some guiding significance for the prevention and control of the risk of spontaneous combustion of coal left in the mining area during rotary mining of the working face.Figure 25 Table 15 Reference 69...