Study Of Gas Emission Law For The First Mining Face In The South Wing Mining Area Of Renjiazhuang Mine

Once a coal seam is exposed or mined, the original gas pressure balance will be destroyed, and then the gas in the coal will be desorbed outward, so the gas bearing capacity in the coal will decrease gradually with the elapse of time. With the advance of the working faces, the coal on the coal walls will be mined and transported out, and the gas in the coal will be released to the airflow of working faces. Furthermore, the lumpiness of coal is different due to the different mining method, so the diffusing speed of the gas in the coal will be different, and then result to the change of gas desorption quantity. In fact, to study the gas emission law of falling coal in the working face is to find out the changing features of gas bearing capacity of the falling coal with time, i.e. the function relation of the intensity of gas desorption quantity of the falling coal and gas emission quantity with time.The forecast of gas emission quantity in working face is based on gas bearing capacity in coal seam and its distribution law, or the changing law of gas emission quantity, combining geological factors, mining factors to select reasonable parameters, and then forecast gas emission quantity by using some methods. At present, the main forecast method of gas emission quantity are statistical method, coalseam gas bearing capacity method and separate source forecast method. The gas emission quantity in the working face of3#coal seam of Renjiazhuang Mine is forecasted by using separate source forecast method...