(中南大学 冶金与环境学院，长沙 410083)
摘 要: 针对硫酸锰电解液中氯离子不断积累并损害电解过程的问题，查阅锰、锌等金属电解液中氟氯的脱除方法并对主要方法进行了归纳总结，结合各方法的优缺点，提出硫酸氧铋作为除氯剂的沉淀除氯新方法，包括“活化-沉淀-再生”三个主要方面，对工艺过程进行了研究。结果表明：在pH=1、温度30 ℃、过量系数1.5、反应时间1 h的条件下，除氯过程的除氯效率达到95.11%，沉淀物主要物相为BiOCl且结晶度良好，处理后液中含氯离子43.96 mg/L，含铋离子110.00 mg/L；再生除氯剂的除氯效率达90.75%，除氯后液含氯降至83.00 mg/L；在除氯后液的深度净化除铋过程中，铋的置换沉淀率可达98.46%，置换后液中含铋1.80 mg/L；最终所得溶液可满足锰电解要求。
关键字: 锰电解液；硫酸氧铋；氯氧铋；除氯；活化；再生
（School of Metallurgy and Environment, Central South University, Changsha 410083, China）
Abstract:A new method of removing Cl- as BiOCl by precipitation was proposed to weaken the negative effect during Mn electrolytic deposition which was taken by Cl-, after reviewing and summarizing relevant references. The new method can be divided into three steps: transforming Bi2O3 to (BiO)2SO4, removing Cl- by precipitation and regeneration. The results show that (BiO)2SO4 is the most ideal Cl- removal agent and the process of boiling in sulfuric acid is necessary. In precipitation, the factors of pH, temperature, excess coefficient and duration time affect the results significantly. Moreover, decreasing pH can dramatically drive the reaction of Cl- removing. The Cl- concentration decreases from 900.00 mg/L to 43.96 mg/L and the Cl- removal rate reaches 95.11% under the optimal condition experiment, and the Cl removal precipitate consists of BiOCl mainly. In regeneration process, BiOCl can be transferred to (BiO)2SO4 by boiling in hot sulfuric acid, and the Cl- removal rate can reach 90.78% when the regeneration removal agent is used. The concentration of remined Bi3+ in Cl- removal solution is declined to 1.80 mg/L by cemented using Mn powders and the cementation rate reaches 98.46%.
Key words: manganese electrolyte; (BiO)2SO4; BiOCl; Cl removal; activation; regeneration
