有色金属(冶炼部分)

以云母型钒页岩为研究对象，结合第一性原理计算与多尺度矿物学表征，系统探讨了钒与杂质元素在云母结构中的占位特征及杂质元素对钒赋存状态的调控作用。通过X射线衍射（XRD）、扫描电子显微镜-能谱分析（SEM-EDS）、综合矿物分析仪（TIMA）以及偏光显微镜等手段表征，证实了钒与Fe、Mg、Al等杂质元素在云母中的空间共生关系。密度泛函理论（DFT）的计算结果表明，钒更倾向于占据八面体中心位点，不同云母结构对杂质元素的容纳方式存在显著差异：白云母中，Fe与Mg以单取代方式占位；金云母中，Fe与Al以三取代方式取代并降低体系能量；黑云母中，杂质取代难以自发发生。态密度（DOS）分析进一步显示，Fe、Mg、Al的引入可显著改变钒的局域电子环境，使V—O键稳定性增强并提高结合能。整体结果表明，杂质元素的占位行为及其与钒的共存效应是控制钒可提取性的关键因素，为钒页岩高效浸出工艺的优化提供了理论依据。

This study focuses on mica-type vanadium shale and aims to elucidate the microscopic mechanisms governing vanadium occurrence and its interaction with impurity elements within mica lattices. By integrating multiscale mineralogical characterization with first-principles calculations, this study systematically investigates the site occupancy of vanadium and impurity elements, as well as the electronic-level regulation of vanadium stability induced by these impurities. Comprehensive mineralogical analyses, including X-ray diffraction(XRD), scanning electron microscopy-energy dispersive spectroscopy(SEM-EDS), TESCAN Integrated Mineral Analyzer(TIMA), and polarizing microscopy, collectively confirm that vanadium is mainly hosted in mica minerals and spatially coexists with Fe, Mg, and Al within the octahedral layers. These results indicate that vanadium is structurally bound rather than present in easily leachable forms, explaining its generally low recovery efficiency in hydrometallurgical extraction. Density functional theory(DFT) simulations were performed to further clarify the atomic-scale substitution behavior and energetic preference of vanadium and impurity elements. The calculations demonstrate that vanadium preferentially occupies octahedral coordination sites within the mica structure, substituting for Al³⁺. However, the mechanisms of impurity accommodation vary among different mica types. In dioctahedral muscovite, Fe and Mg are incorporated through single coordination substitution at the octahedral centers, slightly stabilizing the lattice. In contrast, in trioctahedral phlogopite, Fe and Al atoms enter through tri-coordination, resulting in a significant reduction in total system energy and a stronger lattice stabilization effect. For biotite, however, the replacement of cations by impurities is energetically unfavorable, implying that structural rigidity may restrict element migration and substitution. Further electronic structure analysis based on density of states(DOS) reveals that impurity incorporation exerts a pronounced influence on the local electronic configuration of vanadium. The presence of Fe, Mg, and Al alters the charge distribution around the V— O bonds, enhances orbital hybridization between vanadium 3d and oxygen 2p states, and ultimately increases both the V— O bond strength and the overall binding energy of the system. These modifications contribute to the enhanced structural stability of vanadiumbearing mica but simultaneously reduce the reactivity of vanadium during leaching, providing a fundamental explanation for its refractory behavior. In summary, this work establishes a clear structure-property relationship between impurity element substitution, vanadium site occupancy, and lattice stability in mica-type vanadium shale. The findings highlight that the coexistence and coordinated substitution of Fe, Mg, and Al with vanadium are key factors controlling the extractability and leaching kinetics of vanadium. This study provides not only a theoretical framework for understanding the mineralogical constraints of vanadium occurrence but also valuable guidance for optimizing chemical leaching processes and improving vanadium recovery from shale-type deposits.