Background  Xinjiang serves as an important coal production base in northwestern China. This region holds approximately 40% of China’s predicted coal reserves, with its coal resources primarily distributed in coal-accumulating basins such as Junggar, Yili, Tuha, and Santanghu.

Methods Focusing on strategic metals (e.g., lithium, rare earth elements, zirconium, hafnium, niobium, and tantalum), hazardous metals (e.g., arsenic, mercury, and sodium), radioactive metals (e.g., uranium and thorium), and other heavy metals (e.g., iron and manganese), this study explored the enrichment mechanisms and metallogenic potential of these metallic elements in coals across representative coal-accumulating basins in Xinjiang.

Advances The metallic element enrichment in coals across different coal-accumulating basins in the coal-hosting areas in Xinjiang is subjected to the synergistic control of multiple factors. In the Lower Permian coals, the anomalous enrichment of rare metals is intimately associated with the volcanic activity and magmatic-hydrothermal processes induced by the closure of the Paleo-Tethys Ocean. Within the Jurassic coals in the Junggar Basin, lithium predominantly occurs in aluminosilicate minerals (e.g., kaolinites and illites), while the presence of sodium is attributed to the long-term influence of deep high-salinity groundwater. Within the Jurassic coals in the Yili Basin, uranium enrichment is governed by the variation in the late-stage redox environment, while the synergistic enrichment of arsenic, mercury, and thallium might be associated with sulfide minerals. In the Santanghu Basin, the anomalous lithium enrichment is related to hydrothermal fluid activity. The enrichment degrees and mechanisms of the same metallic element vary significantly across different coalfields/basins. The lithium enrichment in the Santanghu Basin (up to 923 μg/g) differs significantly from that in the Junggar (0.2‒19 μg/g), Yili (2.56‒27.2 μg/g), and Hami (29.6 μg/g) basins, with the latter three showing similar lithium contents in coals. Furthermore, the arsenic and uranium enrichment in the Yili Basin (up to 234 μg/g and 7 270 μg/g, respectively) is significantly higher than that in the Junggar Basin (below 5 μg/g and 82 μg/g, respectively).

Prospects Overall, the enrichment of metallic elements, especially strategic metals, in coals across Xinjiang has metallogenic potential. However, the commercial exploitation of these metallic elements still faces multiple challenges, including unclear spatiotemporal distributions and insufficient exploration of polymetallic assemblages in the Permian-Jurassic coals. To address these issues, it is necessary to employ a multidisciplinary approach that integrates geophysics and geochemistry to determine the enrichment degrees and mechanisms of metallic elements within coal seams deposited in important coal-accumulating basins across Xinjiang. These efforts will promote the collaborative exploitation of strategic metallic elements in coals and contribute to the formation of the Xinjiang model for the comprehensive utilization of coal resources.