An analysis of selected Indiana coals by the particle count method

Abstract

The bituminous coals of Indiana show a characteristic bright and dull banding which is due to alternating bands of five distinct physical constituents, namely, vitrain, clarain, durain, fusain, and mineral matter. A petrographic analysis of Indiana Coals V, VI, and VII was made to determine whether any appreciable variation in the content of these ingredients occurred. The “particle count method” was used in analyzing the coals. In order to establish a standard for comparing Coals V, VI, and VII, an index number was determined for each sample by dividing the combined clarain-durain content by the vitrain content. These index numbers are the most reliable and satisfactory basis for the comparison of coals, and they maybe used to some extent in coal correlation. Because vitrain has the most desirable combustion properties, a coal that has a high vitrain content may be more desirable commercially. Coals VI and VII were found to have a distinctly higher vitrain content than Coal V. Localities of high-vitrain content within the various coal beds in Indiana are outlined in this report. Suggestions for further use of the particle count method in coal analysis are made.