Method for extracting released-gas of protected coal-bedding under unstabilized thin coal bedding set condition

Abstract

A pressure-relief gas drainage method for protected coal seams under the condition of unstable thin coal seams. For mining areas without stable protective seams, a new protective layer is formed by mining the mineable areas of each unstable thin coal seam. The pressure relief gas drainage can effectively reduce the gas content and pressure of outburst coal seams, transform high gas outburst coal seams into low gas outburst non-outburst coal seams, eliminate the risk of coal seam outburst, and realize safe, rapid excavation and efficient recovery of coal and gas outburst coal seams . The roadway in the working face of the outburst coal seam adopts comprehensive mechanized continuous excavation, and the speed of the roadway excavation can be increased from the original 60m / month to more than 200m / month; The gas concentration at the corner of the surface can be controlled below 0.8%, and the gas concentration of the return air flow can be controlled below 0.5%, which has wide practicability in this field.

Description

technical field [0001] The invention relates to a pressure-relief gas drainage method for a protected coal seam under the condition of an unstable thin coal seam group, and is especially suitable for the mining of an unstable thin coal seam group above the protected coal seam. Background technique [0002] The protective layer mining technology has been proved to be the most effective and reliable measure to prevent and control coal and gas outbursts. It has been applied in many mining areas such as Huainan, Huaibei, Songzao, Tianfu, Yangquan and Shenyang, and has achieved good outburst prevention effects. . However, with the increase of mining depth, the gas pressure and content of coal seams gradually increase, and many protective layers of non-outburst coal seams are transformed into outburst coal seams. There are fewer and fewer stable main mining coal seams in the mining area that can be used as protective layers. By mining a layer of coal, it is often impossible to co...

AI Technical Summary

Problems solved by technology

However, with the increase of mining depth, the gas pressure and content of coal seams gradually increase, and many protective layers of non-outburst coal seams are transformed into outburst coal seams. There are fewer and fewer stable main mining coal seams in the mining area that can be used as protective layers. By mining a layer of coal, it is often impossible to completely protect the mining area of ​​the protected coal seam, and it is impossible to realize the regional pressure relief gas drainage of the protected coal seam