Prediction of gas emission zone width in laneway's coal seam based on slippage effect of gas seepage

The width of gas emission zone in laneway's coal seam is an important parameter to predict mine gas emission amount and gas content in the fully mechanized mining face. Based on slippage effect of gas seepage in the coal seam, the width of gas emission zone in laneway's coal seam is theoretically predicted with a combination of experimental test and numerical simulation. The research results show that gas seepage in coal seam with lower pressure will have a slippage effect, and the slippage factor is about 0.24 in test coal sample. Slippage effect has a significant effect for gas emission from coal seam to coal roadway. With increase of exposure time of coal wall, gas pressure in coal seam decreases obviously with considering slippage effect, which is in good agreement with the experimental results. In the meantime with considering the slippage effect, the calculation results of gas emission zone width in laneway's coal seam is basically consistent with the test results, and the relative errors are less than 7%. With exposure time of coal wall increasing, the increment of gas emission zone width decreases gradually, and the power function can be used to well fit the relation of gas emission zone width and exposure time.