Abstract:

Abstract：Based on the problem of the mining under closed distance coal seams group of high-gas at the north of shaqu coal mine, the Strata fracture distribution and evolution, pressure-relief mechanism and the law of gas migration accumulation at goaf of the thin coal seam as upper protective seam mining was analyzed by adopted the method of combining the theory analysis and the test of practice, then the technology of gas extraction at gob-side entry retaining was put forward. This paper departures from the mining practice of the number 22201 first working-face as protective seam, then the technology of pillarless of the filling at gateway beside was introduced, and the parameters of the gas extraction is established. The results of industrial test showed that the effect is obvious about the technology of gas extraction at gob-side entry retaining, which implements the full pressure relief of the under nearby high-gas coal seam group, formed the Y shaped ventilation system of mining face, and reduced the gas of goaf into the working face, which is benefit to the safe and high-efficient mining of high-gas and outburst coal seam group.

Key words: thin coal seam, upper protective seam, pillarless, simultaneous extraction of coal and gas