PROCEDURE FOR IDENTIFYING DISSEMINATED CARBONACEOUS MATTER IN ROCKS AND ORES CONTAINING 'INTERFERING' MINERALS BY THERMAL ANALYSIS

Abstract

Thermal analysis is widely used to determine the composition of disseminated carbonaceous matter (DCM). Experimental studies of other authors and our work have shown that distortion of the temperature curve of CM starts at concentrations exceeding 1 percent for sulfides or 10 to 20 percent for sericite and chlorite. As for carbonates, because they react so sensitively to thermal analysis, the DTA curve will be markedly complicated even when their concentration in the rock exceeds 0.5 percent. To eliminate the effect of 'interfering' minerals, therefore, CM in samples is now concentrated by treating them with acids. We describe procedures for identifying DCM in rocks and ores by thermal analysis without preconcentrating.