Discovery of anomalous molybdenum enrichment in lower Carboniferous coal and its availability and origin
Abstract Less attention has been paid to element variations in lower Carboniferous coal (South China) due to the relatively thin coal-bearing seam thickness, but these variations are of great significance for broad industrial utilization and to evaluate the environmental effects of these coals. This study investigated 34 elemental varations of Carboniferous M2 coal-bearing seam collected from Guizhou Province in South China. The new findings include that molybdenum (Mo) is abnormally enriched in these coals with an mean of 945 mg/kg (0.12–7928 mg/kg), which is 782 and 306 times more than Mo of upper continental crust and Chinese coals. The studied coal bed (Moavg = 2264.89 mg/kg, range = 474 to 7928 mg/kg, ca. 1 m thick) may be utilized as a Mo resource. The Mo origin of the studied Carboniferous coal is influenced by terrigenous inputs and hydrothermal fluids, but the leading Mo source of the Carboniferous coals with anomalous Mo enrichment was derived from the hydrothermal fluids. In addition, Ga and Li have potential applications after recycling, and coal from this seam could be considered to be a Se-rich fertilizer after grinding.