Research and Application of Downward Ventilation Technology for Safe and Efficient Working Face with High Gas Content

In order to solve the technical problems such as gas accumulation in upper corner caused by upward ventilation and unrecoverable extraction pipe in goaf, it is proposed that the coal mining face adopts downward ventilation. By means of numerical simulation, the gas distribution laws in goaf with upward and downard ventilation methods on the stope face of Baode Coal Mine were simulated respectively. The technical parameters of downward ventilation were determined, and the downward ventilation method was adopted in 81505 working face of Baode Coal Mine. The practical results show that the downward ventilation method solves the problem of gas accumulation in the return air corner, realizes the safe recovery of the main extraction pipeline in goaf, solves the safety hazard of the remaining metal pipeline in the goaf, optimizes the roadway layout and lessens a roadway. The comprehensive economic benefit of single coal mining face exceeds 50 million yuan.