College of Materials Science and Engineering, Chongqing University, Chongqing 400044, China.
College of Materials Science and Engineering, Chongqing University, Chongqing 400044, China; National Engineering Research Center for Magnesium Alloys, Chongqing University, Chongqing 400044, China.
J Hazard Mater. 2023 Jun 15;452:131378. doi: 10.1016/j.jhazmat.2023.131378. Epub 2023 Apr 6.
In order to minimize the toxicity of vanadium extraction tailings, the vanadium extraction efficiency should be as high as possible to minimize the residual V(V) content in tailings. In this work, the kinetics of the novel magnesiation roasting of vanadium slag, including the roasting mechanism and kinetic models, is explored to intensify the vanadium extraction. By combination of various characterizations, the microscopic mechanism of magnesiation roasting is revealed, which indicates the simultaneous occurrence of the salt-formation→oxidation routine (major) and the oxidation→salt-formation routine (minor). Macroscopic kinetic model studies show the magnesiation roasting of vanadium slag proceeds in two stages. In the initial 50 min, the roasting follows the Interface Controlled Reaction Model, during which the stable roasting temperature is essential to intensify the magnesiation. In the long-time range (50-90 min), the roasting follows the Ginstling-Brounstein Model, during which the acceleration of air blow rate is most favorable. With intensified roasting kinetics, the vanadium extraction efficiency is as high as 96.65%. This work has provided the guideline to intensify the magnesiation roasting of vanadium slag for vanadium extraction, which can not only minimize the tailing toxicity of vanadium extraction but also accelerate the industrial application of the novel magnesiation roasting technique.
为了降低钒提取尾矿的毒性，应尽可能提高钒提取效率，以降低尾矿中残留的五价钒（V(V)）含量。在这项工作中，探索了一种强化钒提取的新型镁化焙烧法的动力学，包括焙烧机理和动力学模型。通过各种特性的结合，揭示了镁化焙烧的微观机制，表明盐形成→氧化途径（主要）和氧化→盐形成途径（次要）同时发生。宏观动力学模型研究表明，钒渣的镁化焙烧分两个阶段进行。在最初的 50 分钟内，焙烧遵循界面控制反应模型，在此期间，稳定的焙烧温度对强化镁化至关重要。在长时间范围内（50-90 分钟），焙烧遵循金斯特林-布朗斯坦模型，在此期间，加速空气吹速最有利。通过强化焙烧动力学，钒的提取效率高达 96.65%。这项工作为强化钒提取的钒渣镁化焙烧提供了指导，不仅可以降低钒提取的尾矿毒性，还可以加速新型镁化焙烧技术的工业应用。
