Impacts of long-term water inrush on characteristics of coal gas adsorption and seepage

Frequent coal mine flooding is bound to impact not only the stope stress effects of working face, but also the absorption and seepage characteristics of coal mass. In this paper, we examined the effects of long-term water inrush on coal pore structure as well as gas adsorption and seepage characteristics using water-flooded Taoyuan Coal Mine, Anhui Province, China, as an example. Results showed that: 1) after water inrush, the volume, area, and porosity of coal samples, as well as the proportion of micro-pores decreased significantly with the distance from the water inrush site increasing; 2) the amount of gas adsorption of coal samples near the water inrush site was higher than that away from the site; 3) within 13 m from the site, the seepage capacity of coal gas increased; 4) the water seeped into the coal dissolves a mass of inorganic minerals and organic matter and carries them away.