Experimental Study On Adsorption Characteristics And Swelling Deformation Of Mixed Coal

With the continuous improvement of mechanization degree and mining depth of coal mine,the gas content and pressure of coal seam are constantly rising,and the primary coal and tectonic coal coexistcoal and gas outbursts are easy to occur in the mining process of the working face,accompanied by a large number of gas gushing,which seriously restricts the safe and efficient mining of the mine.Therefore,a thorough study on the adsorption characteristics of stratified mixed coal samples and their expansion effects before and after adsorption provides a new idea for the study of coal and gas outburst mechanism.We summarized the research results coal adsorption-desorption characteristics and coal adsorption gas expansion effect system atacially in recent years,and regard Shanxi Tianchi energy co.LTD as the project prototype.Collecting the protoplasm coal and structural coal of its main coal seam no.15 and make mixed coal samples.Using the device ASAP2020 specific surface area of low pressure nitrogen adsorption apparatus,WY-98A gas adsorption constant tester and WT-1 automatic gas radiation initial velocity tester.We carry out experimental study that sample with different mixing coal isothermal adsorption characteristics,radiation characterisics and specific surface area before and after adsorption gas change law.The results show that the specific surface area and adsorption capacity of the mixed coal sample reach the maximum when the mass ratio of the mixed coal sample is 1:1;The adsorption constant a and the initial velocity of dispersion above AP reach the maximum when the mass ratio of mixed coal sample is 1:1,while the adsorption constant b is the minimum;The ratio of the pore specific surface area of the mixed coal samples decreased first and then increased after adsorption;The change of specific surfece area of micropores before and after adsorption was opposite to that of mesopore.A mathematical model was established for the relationship between the change of specific surface area and the stress and strain of pore expansion before and after adsorption of gas in mixed coal samples,and the relationship between the change of pore structure and gas emission before and after adsorption was obtained.The best pre-extraction mode for NO.401 working face was detremined.The research results are valuable to the mechanism of coal and gas outburst and the theory and technical system of accurate gas extraction.