Shale-hosted vanadium occupation in typical silicate mineral structures.

Vanadium is one kind of critical rare metal elements. Recently the domestic demand for vanadium has increased, and its market price has gradually climbed. In-depth study of vanadium extraction technology from shale holds obviously strategic and economic benefits. However, the difficulty of shale-hosted vanadium leaching varies due to the diverse occupancy states and grades in vanadium shale. Additionally, the complex and diverse mineral compositions, severe carbonaceous impregnation and interweaving, and poor lattice integrity complicate the localization of vanadium atoms with current detection technology, making it difficult to elucidate the impact of structural properties on vanadium release. In this paper, we use the first-principles-based density-functional theory (DFT) approach to determine that vanadium is most likely present in the octahedra of silicate mineral minerals, especially Mg-O octahedra, from both energetic and structural perspectives. This study accurately determines the occupancy of vanadium atoms in shale on an atomic scale, clarifies the nature of the ore, identifies targets for disrupting the mineral structure, and serves as a guide for the leaching of vanadium from shale.