Enrichment Mechanism of Lithium in Late Permian Coals in the Bijie Area, Guizhou, China

Abstract

Research on the enrichment mechanism of lithium in coal can increase its economic value. We applied a series of techniques such as X-ray diffraction and ICP-MS to analyze the coal samples collected in the Bijie area and studied the enrichment mechanism of lithium in coal based on the theory of mineralogy and sedimentology. The results show that (1) the highest abundance of lithium in coal is 222 μg/g, the lowest 33.2 μg/g, and the average 87.05 μg/g. Among them, the abundance of lithium in coal samples from Xinhua coalfield and Wenjiaba coalfield reached 136 and 222 μg/g, respectively, which reached the minimum industrial grade (120 μg/g). (2) Lithium in coal was positively correlated not only with ash (0.46) and clay minerals (0.41) but also with total organic matter (0.38) and volatile matter (0.58) in coal, indicating that lithium in coal in the Bijie area has both inorganic and organic origins. (3) The ratio of TiO2/Al2O3, a geochemical index, shows that the maximum ratio is 0.37, and the average is 0.09, indicating that the metal elements are a product of volcanic eruption, and the paleogeographic environment also shows that igneous rocks are exposed in the western provenance area of this study area. (4) The enrichment of lithium in coal is not closely related to the pure marine environment but is closely related to the marine-land transitional environment. In the past, there was a lack of relevant research on lithium in coal in the Bijie area, and the proposal of organic and inorganic coupling causes is of great significance for the development and utilization of lithium in coal.