Zhao Xuxia, Zhang Yimin, Xue Nannan, Hu Pengcheng
School of Resource and Environmental Engineering, Wuhan University of Science and Technology Wuhan 430081 Hubei Province China
State Environmental Protection Key Laboratory of Mineral Metallurgical Resources Utilization and Pollution Control Wuhan 430081 Hubei Province China.
RSC Adv. 2025 Jul 16;15(31):25233-25249. doi: 10.1039/d5ra03987h. eCollection 2025 Jul 15.
Vanadium-bearing shale as a strategic resource is an important raw material for extracting vanadium, and the mechanochemical activation can realize the vanadium extraction by full-wet leaching with green, low-carbon and high efficiency. Based on mineralogical research on mineral composition and distribution, mineral embedded grain size distribution, we employ a graded activation process. The mechanism of mechanochemical activation-enhanced dissolution of vanadium-bearing shale is revealed through the relationship between activation kinetics and vanadium leaching as well as the fluorine adsorption process on different minerals surfaces of vanadium-bearing shale. Vanadium-bearing shale is mainly composed of quartz, muscovite, calcite, pyrite, feldspar and apatite. Vanadium with 94.24% exists in muscovite, while the remaining 5.76% exists in oxide. Muscovite is predominantly closely associated with quartz, calcite and organic carbonaceous and tends to be enriched in fine grained, displaying fine disseminated granularity with 0.005-0.06 mm. The grindability order of vanadium-bearing shale is observed as follows: -3 to +2.5 mm < -2.5 to +2 mm < -2 to +1 mm < -1 to +0.6 mm. The activation process of different particle sizes were well evaluated by kinetic equations ( = 0.99). The vanadium leaching efficiency has a positive linear relationship with the activation yield at the optimal leaching particle size with -0.6 mm. The vanadium leaching efficiency and activation time can be expressed by equation of = exp(- ) + . The mineral surface of vanadium-bearing shale has a good adsorption of F (23.89 mg g) undergoing amorphous phenomena. The order of F adsorption capacity is calcite, pyrite, dolomite, muscovite, feldspar, and quartz. The adsorption process of F alters the surface potential on the vanadium-bearing shale, and the negative charge on the of muscovite surface increases, while that of pyrite and calcite decreases, which is conducive to the diffusion of H to the surface of muscovite and away from pyrite and calcite. F generates CaF with the surface of calcite and FeF with Fe(iii)-S on the surface of pyrite, hindering and slowing down the dissolution of calcite and pyrite. F forms Al-F and Si-F bonds with Si and Al on the surface of muscovite, promoting the dissolution of muscovite.
含钒页岩作为一种战略资源，是提取钒的重要原料，机械化学活化可实现绿色、低碳、高效的全湿法浸出提钒。基于对矿物组成与分布、矿物嵌布粒度分布的矿物学研究，我们采用分级活化工艺。通过活化动力学与钒浸出之间的关系以及含钒页岩不同矿物表面的氟吸附过程，揭示了机械化学活化强化含钒页岩溶解的机理。含钒页岩主要由石英、白云母、方解石、黄铁矿、长石和磷灰石组成。94.24%的钒存在于白云母中，其余5.76%存在于氧化物中。白云母主要与石英、方解石和有机碳质紧密共生，且倾向于在细粒中富集，呈现出0.005 - 0.06毫米的细分散粒度。观察到含钒页岩的可磨性顺序如下：-3至+2.5毫米＜-2.5至+2毫米＜-2至+1毫米＜-1至+0.6毫米。通过动力学方程（ = 0.99）对不同粒径的活化过程进行了很好的评估。在最佳浸出粒径为-0.6毫米时，钒浸出效率与活化产率呈正线性关系。钒浸出效率和活化时间可用方程 = exp(- ) + 表示。含钒页岩的矿物表面对F具有良好的吸附作用（2×3.89毫克/克），呈现非晶态现象。F吸附能力顺序为方解石、黄铁矿、白云石、白云母、长石和石英。F的吸附过程改变了含钒页岩的表面电位，白云母表面的负电荷增加，而黄铁矿和方解石表面的负电荷减少，这有利于H向白云母表面扩散并远离黄铁矿和方解石。F与方解石表面生成CaF₂，与黄铁矿表面的Fe(III)-S生成FeF₃，阻碍并减缓了方解石和黄铁矿的溶解。F与白云母表面的Si和Al形成Al-F和Si-F键，促进了白云母的溶解。
