Microcrystalline characterization and morphological structure of tectonic anthracite using XRD, liquid nitrogen adsorption, mercury porosimetry and micro-CT

Tectonic deformation acts on an indispensable factor affecting the crystalline structure, but its relationship on the evolution mechanism of morphological structure is seldom considered. In this work, the characterization of microcrystalline and morphological structures in the tectonic coal was comprehensively explored using XRD, pore structure analyzers (N2 adsorption and mercury intrusion methods) and micro-CT. The XRD results indicate that the transformation of chemical composition was observed in the coal body after the continuous tectonic deformation. Meanwhile, the variation in microcrystalline parameters, such as the interlayer spacing, stacking height, effective stacking layer number, aromaticity and graphitization degree, reveal that the microcrystalline structure of tectonic has experienced the positive evolution with graphitization and aromatization. Pore morphological analyses demonstrate pore volume distributions of micropore, mesopore and macropore were totally enhanced by tectonism while th...