Protective Seam Method for Gas Control in Deep Well Fully Mechanized Soft Coal Face

摘要

The 1117(1) working face mining depth of Guqiao coal mine was at a level of-800m and had an average absolute gas emission of 52 m3/min,withthe highest gas emission of 64 m3/min.By using surface drilling,roof strike drilling,and burying pipes in tail roadway,the average gas extraction volumereached 36.3 m3/min and the gas extraction rate,70%,completely eliminating the restriction of gas on production,making the safe and high efficientexploitation be realized,with the daily output reaching 15 kt.