关键词: 坚硬上保护层, 综采, 无煤柱开采, 煤岩与瓦斯共采, 灾害治理

Abstract: During the Baijiao mining of close distance protected coal seams it has such problems as, hard upper protective layer, hard and thick dirt band, concentrated faults, hard immediate roof, high gas emission in low overlying protected seam and frequent gas exceeding. To solve the complex technological problems, the author proposed series of disaster prevention methods of fully mechanized excavation and mining, reasonable selection of coal and rock hard fully mechanized equipment, the integrated vertical gas extraction, no pillar mining with gob-side entry, Y-ventilation and equalizing fire-fighting technology. The technology has been tested in the mining of protective layer in the 2421 mining face, it results that after mining the upper protective layer, the overlying coal seam permeability coefficient increases more than 1300 times, the gas drainage volume improved 173 times, the outburst danger has been sharply reduced, and the gas exceeding problem has not happened during drilling and mining. The technology has achieved good economic and social benefits in the mining.

Key words: the hard upper protective layer, fully-mechanized coal mining, no pillar mining, coal and gas simultaneous extraction, disaster contro