Research On The Gas Content Determination Method And The Gas Content Index Critical Value Of Regional Prediction In The B₁ Coal Bed Of YuXi

The gas in the coal and gas outburst plays an important role, it has important significance for the preventing of coal and gas outburst by determining of coal seam methane content accuracily.Combining the practical measured data of local and laboratory ,this thesis studied the influence factors of the coal seam methane content systemic。Aimed at the problems of gas content determination,this thesis has analyzed the key factors of the influence of coal seam gas content determination: Via studying the desorption law of the coal samples, determined that the method of t is reasonable to calculate the loss of methane content ;In order to determine the suitable loss time of the coal seam methane, on the test, determine the methane content of GaoCheng mine in laboratory under different pressure, take the coal exposed respectively 2min,5min,8min and using the calculation method of t for the calculate of loss quantity,meanwhile comparative analysis the loss and desorption quantity ,teemed that 2min appropriate for the loss of time.Through investigation three different particle size of coal sample and combined with underground determination,the drilling powder conform to the requesting of underground gas content determination. Describing the influence of gas content determination by the gas emission width briefly,determining the reasonable sampling depth;Inspect the influence of determining coal seam gas content with different sampling method,identified round pipe wind row powder is the reasonable sampling method;Confirmed the coal and gas outburst gas content index critical value of MengJin and GaoCheng.Based on actual checking in MengJin mine,it is indicated that it has high accuracy and reliability on coal seam gas content determination by using the achievements of this paper and it is satisfy to forecasting gas content during the mine mining process accurately .