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Rare Earth Elements (REEs) in the Late Carboniferous Coal from the Heidaigou Mine, Inner Mongolia, China

This paper discusses the rare earth elements in the No. 6 Coal (Late Carboniferous) in the Heidaigou Mine of Inner Mongolia, northern China. The results show that the vitrinite reflectance (0.57%) is lowest and the proportions of inertinite and liptinite (32.4% and 5.4%, respectively) in the No. 6 Coal of the Heidaigou Mine are highest among all of the Late Paleozoic coals in the Ordos Basin. The No. 6 Coal was significantly enriched in rare earth elements (346 μg/g) as compared with those of Chinese coals, Guizhou coals of China, and US coals. The REEs in the coal are supplied from the sediment-source region, and the REEs leached from the adjacent partings by groundwater.