The present study evaluates the reductive leaching of indium from indium-bearing zinc ferrite using oxalic acid as a reducer in sulfuric acid solution. The effect of main factors affecting the process rate, including the oxalic-acid-to-sulfuric-acid ratio, stirring rate, grain size, temperature, and the initial concentration of synergic acid, was precisely evaluated. The results confirmed the acceptable efficiency of dissolving indium in the presence of oxalic acid. The shrinking-core model with a chemical-reaction-controlled step can correctly describe the kinetics of indium dissolution. On the basis of an apparent activation energy of 44.55 kJ/mol and a reaction order with respect to the acid concentration of 1.14, the presence of oxalic acid was found to reduce the sensitivity to temperature changes and to increase the effect of changes in acid concentration. Finally, the equation of the kinetic model based on the factors under study is presented.

本研究评估了草酸作为硫酸溶液的还原剂，从含铟铁氧体中铟的还原浸出。精确评估了影响加工速度的主要因素的影响，包括草酸与硫酸的比例，搅拌速度，粒度，温度和协同酸的初始浓度。结果证实了在草酸存在下溶解铟的可接受的效率。具有化学反应控制步骤的收缩核模型可以正确描述铟溶解的动力学。根据表观活化能为44.55 kJ / mol和相对于酸浓度为1.14的反应顺序，草酸的存在降低了对温度变化的敏感性并增加了酸浓度变化的影响。最后，提出了基于所研究因素的动力学模型方程。