Abstract: In order to improve the understandings of pore structures and adsorption properties of outburst coal mined at typical mining fields in Guizhou Province, such structures and properties are tested by using related apparatuses based on their importance on the extraction of coal gas (coalbed methane) and the prevention coal and gas outburst of happening. Results show that a number of crystal materials and micropores exist on the surface of coal samples’ parallel beddings; one or several fractures in parallel or intersected with different sizes can be observed on the surface of samples’ vertical joints. The distribution of diameters of sample’s pores or fractures is mostly from 0 to 10 nm, and micropores with a diameter of 3 nm to 5 nm are the most abundant in coal samples, which are also the main spaces to adsorb the coal gas. When the relative pressure reaches about 0.8, the gas adsorption volume would increase greatly. The gas adsorption volumes change for different samples, generally, the bigger pore volume has more adsorption volume.

Key words: outburst coal, pore structure, adsorption property, isotherm curve of adsorption- desorption, experimental study