Gas Control Technology during Initial Mining of Fully-mechanized Mining Face in Outburst Coal Seam
Under the influence of factors such as large hanging area of goaf,high gas content in coal seam and high concentration gas emission in goaf,gas overlimit is easy to be caused,and even safety accidents are induced in the fully-mechanized mining face with hard roof of outburst coal seam during initial mining.Therefore,based on the engineering background of 6203 fully-mechanized mining face,gas control measures to strengthen gas extraction during initial mining were put forward.Firstly,the air distribution volume during the initial mining period was appropriately increased to improve the wind exhaust gas capacity;secondly,the parameters of the upper borehole were optimized,and the effect of gas extraction in the goaf was improved by reducing the distance between the final hole of the upper borehole and the roof of 6#coal seam,and increasing its coverage;then,the number of coal seam holes was increased,and large-diameter low-negative pressure extraction pipes were arranged in the air return trough to realize the gas extraction within the range of 6-12 m in the goaf,strengthen the coal seam gas extraction effect in the initial mining range,and reduce the gas emission during the mining period;finally,in practical engineering applications,no abnormal gas gushing occurred during the initial mining of 6203 fully-mechanized mining face,and the gas volume fraction in each area of the mining face remained within the safe range.
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维普
