| Work top corner gas overrun has become the bottleneck problem of coal mine safetyproduction, greatly limits the mine production capacity; Long and large diameter roof to drill the gas extraction technology is extremely effective method to solve this problem, which is constructed. the gas mine gas extraction of full-mechanized caving mining face in the future development trend. In view of this, this paper, taking Shanxi Jin Energy Mabu coal mine 8204 fully mechanized coal working face as the background, using the combination of theoretical analysis, numerical simulation and field test, the method of analyzing the influence factors of 8204 fully mechanized coal face gas emission, research working face mining overburden evolution law of mining-induced fractures, determine the height of fractured zone in the three zones and horizontal three areas, the abscission zone, the long borehole lamilloy parameter design and analysis of the effect of long drill gas drainage is adopted in this study.8204 fully mechanized coal face is obtained by using the empirical formula method caving zone height is 8.76m, fractured zone height of 36.83m; Overburden deformation law of FLAC3D numerical simulation, determine caving zone height is 11 m, fractured zone height is 33m, with the empirical formula calculation results conform to. Through the formula to calculate long borehole end point from the return air along the trough level from 0-55m, gas extraction effect is best.Large diameter roof to long after the introduction of gas drilling technology, the extraction data monitoring, found that the extraction of gas drilling total up to 33m3/min, the effective extraction time of 68 days, and the mine is the total extraction using high alley pumping 15m3/min, the effective extraction time was only 37 days; Total gas extraction and effective extraction time are 2 times, on the corner gas concentration from 1.83% to 1.83%, on advancing speed from previous 13m to 42m, extraction effect is more ideal. |
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