Study on the Law of Gas Desorption of Lump Coal Samples under Uniaxial Compression

Taking the mining influence on the gas desorption characteristics of coal body into consider, a new gas adsorption and desorption system of coal sample under compression was manufactured. Using this test system, the gas desorption characters of coal samples were experimented under different gas pressure with some uniaxial compress pressure and different uniaxial compress pressure with constant gas pressure. The experimental results show that: 1) under the same uniaxial compress load, the greater the initial gas pressure is in coal samples, the greater the cumulative desorption capacity is; 2) under the same initial gas pressure, the cumulative desorption capacity of coal not only relates to the load, but also has to do with internal pore structure and other factors of coal body; 3) fitting the experimental data with different empirical formula, the mathematical model of gas desorption of coal samples under uniaxial compression with different gas pressure was obtained. The results of this paper can provide some guidance for gas drainage in gas coal mine and those can improve the further understanding of gas adsorption and desorption in coal body under mining influence.