Insights into the Nanoscale Microstructure Diversity of Different Rank Coals
Baisheng Nie, Dan Zhao, Xueqiu He, Fanbei Kong, Hao Zhang, Xianfeng Liu, Bozhi Deng, Jiayun Lun
Abstract
The gas flow pattern of the coal seam is closely related to the pore structure of the coal. In order to better understand the pore distribution in different coal samples, the pore distribution and fractal dimension characteristics of five coal samples with different degrees of metamorphism were investigated and analyzed by using the low-temperature nitrogen adsorption method and CO2 adsorption methods based on the fractal theory. The results showed that the higher the degree of metamorphism, the better the pore development, and the fractal dimension of micropores and mesopores varied with the degree of metamorphism. The pore variability between the outburst and non-outburst coals is mainly in the stage of micropores, with the outburst coal having a larger pore volume and specific surface area and a more complex microstructure. The pore formation and distribution patterns of different coal samples under the combined influence of geological and coalification effects are discussed.