Modes of occurrence and origin of mineral matter in the Palaeogene coal (No. 19-2) from the Hunchun Coalfield, Jilin Province, China

Previous investigations on minerals and elements in coals from northeastern China are very scarce. This paper investigates the mineralogy and geochemistry of the Palaeogene No. 19-2 Coal, parting, and host rocks (roof and floor strata) in the Baliancheng mine, Hunchun Coalfield, Jilin Province, northeastern China. Samples collected from this coalfield were analyzed using low-temperature ashing plus X-ray diffraction analysis, scanning electron microscopy in combination with energy-dispersive X-ray spectrometry, X-ray fluorescence spectrometry, and inductively coupled plasma mass spectrometry. The investigated coal is of subbituminous A to high volatile bituminous rank (0.50–0.56% Ro,ran) and has a low sulfur content (0.25% on average). The mineral assemblage of the coal is dominated by kaolinite, illite and expandable clays, and quartz, with a trace of albite. In comparison with low-rank coals worldwide, the No. 19-2 Coal is enriched in Cs, V, and Mo.