Experimental Study On Dust Control By The Coal Seam Water Infusion In Advanced Pressure Relief Stage Using Bedding Gas Hole

Coal seam water infusion as an coal working face dust prevention measure has apractical application and it usually needs to construct specialized hole. While in order to gasextraction it has been decorated bedding gas extraction hole in high gas mine. Gas extractionand coal seam water infusion causes the conflict not only the time but also space. In order tosolve this problem, this paper put forward a new idea, which makes use of gas drainage holefor water infusion in advanced pressure relief stage, by the way of “gas drainage hole-waterinfusion hole-gas drainage hole” water interval infusion. And it designs a test in No.9801working face of Kaiyuan Mine of Yang Mei group.The results showed that the rate of coal seam water infusion grows distinctly in the scopeof lead abutment pressure ahead of the coal face. Making full use of the advance abutmentpressure region is an important way to ensure the effect of coal seam water infusion. Thestress begins to decline from the peak in20m ahead of working face. The rate of waterinfusion grows distinctly, which reached the highest rate2.88m3/h,4.5~9.6times the rate oforiginal. The quality of construction and borehole sealing as well as the water infusionpressure are the key factor affecting the effects of water infusion.35m,25m,10m waterinfusion advanced distance, wetting radius is2.2m,1.9m and1.9m respectively in this testconditions. Dust reducing rate is25.74%、22.93%、16.71%respectively.Influence of coal seam water infusion for the gas extraction can be divided into twostages. The first stage is water flooding to disperse the gas. The second stage is water infusioninhibiting gas releasing. The first stage takes short time, from beginning of infusion to the bigcoal-bed fractures filled with water. While the second stage takes long time, from the bigcoal-bed fractures filled with water to the end of water infusion.Testing face is suitable to adopt “gas drainage hole-water infusion hole-gas drainagehole” interval water infusion method. The water infusion advanced distance is about25~30m.The water infusion pressure is about8to15MPa. The single water infusion rate15~25m3.