Petrologic method of analysis of nonmaceral microstructures in coal

Coals commonly contain important microstructures that are not included in a maceral analysis but may significantly affect the coals utilization performance. The current work describes a microscopic technique for determining the nonmaceral microstructure composition of coal. The microstructures allocated to normal coal, fines, pseudovitrinoids, microbrecciation, oxidized coal (weathered or thermal), coarse mineral matter, cenospheres, and contamination have been described and illustrated and some indication of their origin has been suggested. The nonmaceral microstructure analysis of coal, if applied as a supplement to the routine maceral and vitrinoid reflectance analysis of coals, may serve as an instrument for explaining the anomalous behavior of some coals and aid in improving the predictions of carbonization characteristics of coking coals.