Study on emission and adsorption characteristics of tectonic coal and original-structure coal

Gas adsorption and emission characteristics of two kinds of coal from five pairs of mines were studied. The adsorption experiment show that tectonic coal have a little higher adsorption capacity than original-structure-coal and changing amplitude increases as coal rank decreases. And Langmuir adsorption constant "a" of tectonic coal is bigger than original-structure-coal with a variation about 1%~4%, while adsorption constant "b" have no obvious change. By estimation of specific surface free energy, it is found that most tectonic coal have a higher surface activity. The gas emission experiment show that tectonic coal samples have a 14%~25% higher initial diffusion speed of tectonic coal except Qilin mine which indicates tectonic coal have a stronger gas emission capacity. The results reveal that tectonic coal have a broken structure which not only enhances adsorption but also emission capacity. And these characteristics contribute to coal and gas outburst occurs.