低透气松软突出煤层快速揭煤技术

Fast Coal Opening in Low Gas Permeability Crumby Coal Seams

随着矿井开采深度的加大,矿井的透气性越来越小,煤与瓦斯突出事故频发,揭煤难度也越来越大。孟津煤矿开采山西组二1煤层,属于构造煤,煤层松软,透气性低,矿井一水平开采深度为760m,瓦斯压力高。副井清理斜巷需穿过二1煤层,为了尽快揭开煤层,采用液压钻机配乳化液泵以提高钻探水压的冲煤措施,使高应力低透气松软煤层在揭煤时的不利因素转化为可利用因素。从施工的55个揭煤孔来看,单孔冲出煤量最大为2.3t,最小为0.4t,平均为1.06t,总计冲出煤量为58.5t。通过对控制区域6个点瓦斯含量的测定,结果表明,瓦斯含量降到了8m3/t以下,清除了突出危险。采用瓦斯解析指标进行了三次效果检验,Δh2最大值为190MPa;在岩柱1.5m布置爆破孔,采用震动爆破揭开煤层,瞬时最大瓦斯涌出量为2.4m3/min,说明达到了快速揭煤的目的。

Along with increasing mining depth, strata gas permeability is getting increasingly smaller, accidents of coal and gas outburst happening frequently, coal opening also getting more and more difficult. The Ill coal seam in the Shanxi Formation is mined in the Mengjin coalmine. The coal seam belongs to crumby and low gas permeability tectonoclastic coal; the mining depth of first level is 760m with high gas pressure. To clean-up dip switch of auxiliary shaft needs to penetrate through Ill coal seam, for as quickly as possible to open the coal seam, hydraulic drilling rig matching up with emulsion pump to blanking coal with increased water pressure, conversed deterring factors into utilizable factors of heavily stressed low gas permeability crumby coal seam at coal opening. From 55 coal-opening boreholes drilled, single borehole blanked coal quantity is 2.3 tons maximum, minimum 0.4 tons, average 1.06 tons, total coal blanked 58.5 tons. Through gas content measurement of 6 points in controlled area has demonstrated that gas content lowered down to under 8m3/t , and eliminated gas outburst hazard. To use gas desorption indices carried out effect validation 3 times, maximum Ah2 is 190MPa, arranged a blast-hole at 1.5m of rock pillar, shock blasting has used to open coal seam, instantaneous maximum gas emission is 2.4m3/min, and fast coal opening achieved.