Abstract:

Due to the influence of coal mining to replace, there exists the problem of the gas concentration exceeding limits in the process of work face mining, which with short extraction time. By arranging blast hole in the middle of gas extraction holes, charging with a diameter of 63mm water gel explosive grain of coal mine gas extraction to increase permeability of the mining-coal bed by advanced deep hole pre-splitting blasting. With the method used in field application ,the concentration of gas extracted is increased by 2.2 times, the flow rate increased by more than five times, coal seam permeability is increased greatly, working face advancing speed increased by 3 times, the problem of gas overrun is solved effectively.

Key words: deep hole pre-splitting blasting, coal seam permeability, water gel explosive grain of coal mine gas extraction, fully-mechanized face