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Abstract:
Gob-side entry retaining has the advantages of reducing the loss of coal pillars, reducing the amount of excavation works, and alleviating the tension of the connection between extraction and mining, and its application is becoming more and more common. However, the application of the middle gangue retaining bracket not only facilitates the hanging and injection molding, but also forms a drawer-type semi-enclosed space, which is easy to accumulate gas, which has become the focus and difficulty of gas management. Aiming at the problem of gas control in the gob area of the Y-type ventilation continuous mining face, a gas control technology is proposed to use the inclined directional long boreholes to drain the gob area across the working face, and form a gas extraction method for the gob area and the mining face across the working face. It reduces the gas accumulation in the adjacent goaf, and can effectively prevent the gas disaster caused by the sudden fan-out of the gas in the goaf when the roof collapses in a large area. The test in Dongfeng Coal Mine shows that the construction tends to drill holes from high positions to the cracks in the roof of the old goaf, and continue to extract the gas in the old gob. The gas concentration in the upper corner is reduced from 0.67% to 0.22%, and the gas concentration in the return air flow is reduced from 0.47%. It is reduced to 0.18%, and the gas storage in the goaf and its roof crack zone is minimized, and the ideal effect is achieved, and the gas control effect is remarkable.