Gas Comprehensive Control Technology of Fully Mechanized Top Coal Caving Mining Face

In order to solve the frequent gas content over limit problem occurred during the mining process of No.P41102 fully mechanized top coal caving mining f ace in Wangjiazhai Mine, with the boreholes layout along the mining seam for the gas drainage, the gas emission value from the mining process was effectively reduce d.Within a 30 m scope in the goaf, the gas drainage pipeline with a diameter of 250 mm buried were applied to the gas drainage in the goaf.The gas content in the air re tuning flow was reduced.High level boreholes set at the 15 m in the seam roof were applied to the pressure releasing and the gas drainage in the up neighboring strata with obvious effects. The gas drainage value was reached to 27.05 m3/min, the gas drainage rate was reached to 69.5% and the month advancing rate of the coal minin g face was improved over 30 m.The month production capacity of the coal mining face was improved with 86 851.6 t in average. The elimination of the gas content over I imit could ensure the safety and high efficient production of the coal mining face.