Analysis of Influencing Factors of Gas Release in Isolated Working Face and Demonstration of Necessity of Pre-pumping

In view of the low gas content of coal seam in fully mechanized top coal caving face of high gassy mine and the large amount of gas emission during the mining period under the influence of mining conditions, reasonable gas control measures are selected to avoid the blindness of gas control. Through the similar working face gas control measures and effect analysis, the work surface pre-pumping effect is poor, even without the need for pre-pumping. In order to further demonstrate the necessity of pre-pumping of I011502 face, the main factors are as follows: the influencing factors of gas release in isolated island face, the demonstration of residual gas content in I011502 face, the demonstration of gas treatment effect of I011501 working face and the demonstration of I011502 analysis on the protection of gas control measures in the period of mining. The results show that the maximum absolute gas emission during the mining period is 12.78 m³/ min, and the high-level borehole gas extraction is 10 m³/ min during the mining period. The remaining 2.78 m³/min of gas extraction in the working face excluding high level drilling is far smaller than the 4.96 m³/min of gas extraction in the working face, which ensures that the gas concentration of return air flow is not more than 0.5% during working face mining.