Influence of Gas Absorption by Coal Body Surface Fractal

It taking eight kinds different metamorphic degree coal sample as studying objects，some laboratory methods as high pressure volumetric method and low pressure nitrogen absorption were applied，coal surface fractal characters and absorption property of coal sample were analyzed，then fractal dimension of coal sample were obtained by FHH function.The results showed that gas absorption ability of different coal sample were different obviously，gas absorption was influenced by coal surface fractal obviously，with coal rank increased，fractal dimension presented climb up and then decline as U-shaped relationship.