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Abstract Considering the low permeability coefficient of coal seam and gas flow attenuation coefficient of borehole at 1205 working face of Sima Mine, led to low efficiency of gas extraction and gas over limit in working face, etc., slit-to-crack technology was adopted to No. 3 coal seam in 1205 working face, after the implementation, the permeability coefficient of coal seam was increased by 2 times, the gas extraction efficiency was increased to 57%, and the gas concentration was reduced to less than 0.8% during the mining, with remarkable application results.
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