Three-dimensional Gas Extraction Technology for Goaf in Coal Mining Face
In response to the problems of high gas emission and high gas volume fraction in the return air corner and return air flow of 3307 coal mining face,a three-dimensional gas extraction technology mainly consisting of"high-level drilling+transverse closed wall buried pipe+bottom extraction roadway closed wall buried pipe"was constructed based on the on-site situation of the mining face.There were two types of high-level drilling:directional long drilling on the roof and ordinary high-level drilling,which can effectively deal with complex geological structures during mining.The transverse closed wall buried pipe can change the gas flow field in the goaf,reduce the amount of gas emission in the goaf,and the bottom pumping roadway closed wall buried pipe can keep the bottom pumping roadway in a low negative pressure zone and intercept the bottom pressure relief gas and the bottom crack gas in the goaf.After on-site application,the gas volume fraction of the return air corner and return air flow during the mining period of 3307 coal mining face were within a safe range,with the highest volume fraction controlled within 0.63%,effectively ensuring the safety of the working face.
coal mining facegas emission quantitythree-dimensional gas extraction
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