Study on influence of stress on desorption characteristics of coal containing gas

The rise of in-situ stress and severe mining disturbances during deep mining can easily form stress concentration areas on the mining face,leading to the stress-dominant outburst accidents and shock-gas compound dynamic disasters. In order to improve the accuracy of gas disaster management,the coal sample of Jiulishan Mine in Jiaozuo was used as the research objective to explore the influence of stress on the desorption and emission characteristics of gas-containing coal during deep mining. The isothermal desorption and constant-pressure desorption experiments of loading coal samples were carried out by using a triaxial seepage-adsorption-desorption device. Then,the influence of stress on the desorption characteristics was analyzed. Results showed that,the gas emission in stress-dominant areas are controlled by the stress because the stress dominates the gas desorption capacity. The cumulative amount of gas desorption and the initial desorption rate gradually increase with the growing stress when they have the same quantity of gas adsorption,while the desorption rate attenuation index reduces slightly with the rising stress,showing that the stress effect promotes the gas desorption capacity the coal sample. Compared with the stress-response desorption capacity of He and CH4,the conclusion that the stress improves the gas desorption and reduce the adsorption capacity was validated. This work clarified the influence of stress on the desorption and emission characteristics of gas-containing coal,and revealed the inducing effect of stress on gas desorption in coal matrix,which is of a great significance to the prevention and control of gas disasters and coalbed methane in deep coal mining.