Relations between the reflection coefficients of the basic groups of macerals: A review

Abstract

Quantitative relations are found between the structural and chemical characteristics of macerals of the basic coal groups (vitrinite Vt, inertinite I, liptinite L), on the one hand, and their reflection coefficients Rr and the corresponding dispersions σR, on the other. For coal of a particular metamorphic stage, the reflection coefficient declines in the series I > Vt > L, on account of the reduction in aromatic chemical structure and in the degree of condensation of the aromatic blocks. In the metamorphic series, the reflection coefficients of the macerals rise; the values for Vt and L at intermediate stages converge. The dispersion of the reflection coefficients (and hence the reflectograms) is due to the spread in characteristics of the chemical structure of the coal’s organic content, as confirmed by calculations for the vitrinite of D, G, Zh, and K coal.