Study of the Morphology and Structure of Coal Vitrinites
S. A. SOZINOV, A. N. POPOVA, N. I. FEDOROVA, Z. R. ISMAGILOV
Federal Research Center of Coal and Coal Chemistry, Siberian Branch of the Russian Academy of Sciences, Novosibirsk, Russia
Keywords: scanning electron microscopy, X-ray diffraction, X-ray structural parameters, coal vitrinites, arene layers
Pages: 686-692
Abstract
Vitrinite concentrates of coal at different stages of metamorphism are studied by means of scanning electron microscopy and X-ray diffraction analysis. The results show that the cleaves and fractures on the surface of maceral particles have a structure characteristic of vitreous amorphous bodies for the whole metamosphism series. An increase in metamorphism degree is accompanied by an increase in the electrical conductivity of vitrinite particles and a decrease in the reflectivity with respect to electrons due to a decrease in the content of oxygen atoms. It is shown by means of X-ray diffraction that vitrinites have a turbostratic carbon structure, formed by polyarene layers with the interlayer spacing (d002) decreasing from 3.64 to 3.50 Å with an increase in metamorphism stage, at the same time an increase in the dimensions of structured vitrinite fragments - height (Lc) andd width (La) of arene layer packets - is observed. A linear dependence is revealed between d002 and vitrinite reflectance.
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