树脂离子交换提取拜耳法流程中钒的动力学

采用201′7树脂对拜耳法生产Al2O3流程中种分母液沉钒后再浸出，对制得的Na2VO4溶液进行了静态吸附动力学研究，分析了吸附机理. 采用批式离子交换法，考察了树脂粒径、温度、搅拌速率、溶液浓度对离子交换过程的影响，并用动边界模型对树脂吸附钒的离子交换过程进行了描述. 结果表明，离子交换过程由颗粒内扩散控制，搅拌速率和反应温度对交换速率影响较小，吸附速率随Na2VO4溶液中钒初始浓度的增加而升高；交换过程的反应速率常数为10.052 cm4/(mol×s)，反应级数n为0.5507，表观活化能为39.67 kJ/mol. 吸附机理分析结果表明，在动力学实验过程中201′7树脂主要吸附的钒阴离子为V10O286-.

Kinetics Research on Recovery of Vanadium from Bayer Process by Ion Exchange with Resin

Static adsorption kinetics of sodium vanadate by 201′7 resin was studied, and the adsorption mechanism analyzed. The sodium vanadate was prepared by precipitating vanadium from spent liquor of Bayer process and then leached. In optional reaction system, the influences of granularity of resin, temperature, stirring speed and concentration of sodium vanadate on the ion exchange process were investigated by batch ion exchange method. Moving boundary model was applied to describe the kinetics of ion exchange process. The results showed that the dominant procedure was ion diffusion through particles. The influences of stirring speed and temperature on the adsorption were little, the adsorption rate increased with the rise of primary consistency of sodium vanadate. The rate constant of exchange (k0), order reaction (n) and the apparent activation energy (Ea) were obtained: k0=10.052 cm4/(mol×s), n=0.5507, Ea=39.67 kJ/mol. The results of adsorption mechanism analysis show that the main anion of vanadium adsorbed by 201′7 resin during the kinetic experiments was V10O286-.