Experimental study on effect of pore structure of coal on gas adsorption and dispersion properties

Abstract

In order to reveal the influence mechanism of pore characteristics parameters of coal body on gas adsorption and diffusion, eight sets of coal samples from Ningtiaota Coal Mine were selected for experiments on pressure mercury, gas adsorption constants and initial velocity of gas dispersion, and the pore fractal characteristics of coal samples and their influence on gas adsorption and diffusion characteristics were analyzed based on Menger sponge fractal model. The results show that the pore volume of coal sample is dominated by microporous pores, followed by transitional pores, mesopores and macropores, microporous pores play a dominant role in the pore volume of coal sample, which are mainly closed and semi-open pores, and mesopores and macropores are mainly open pores. The fractal dimension D2 is linearly related to the adsorption constant a. As the fractal dimension D2 increases, the adsorption constant a gradually increases, and the initial velocity of gas diffusion gradually decreases with the increase of fractal dimension D2, and the weaker the gas dispersion performance.

Keywords

• pore structure
• mercury intrusion method
• fractal dimension
• gas discharge initial velocity
• adsorption characteristics