Study of the Morphology and Structure of Coal Vitrinites

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 se-ries. 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 angstrom with an increase in metamor-phism 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 reflec-tance.

Automated summary

The vitrinite concentrates of coal at different stages of metamorphism were studied using scanning electron microscopy and X-ray diffraction analysis. The results showed that an increase in metamorphism degree led to an increase in electrical conductivity and a decrease in reflectivity of vitrinite particles. X-ray diffraction analysis revealed the formation of a turbostratic carbon structure in the vitrinites, with an increase in metamorphism stage resulting in an increase in the dimensions of structured vitrinite fragments.