Abstract In this study, a novel, efficient, and eco-friendly method is proposed to precipitate Cl− as BiOCl from MnSO4 electrolyte using (BiO)2SO4 as the chloride removal agent. The effects of different factors on the transformation and activation of Cl− removal agent, chloride precipitation, recovery and recycling, and purification processes were investigated. Increasing the L/S ratio could promote transformation and activation, while low temperature and low pH could have positive effects on Cl− precipitation. Under optimal conditions, the chloride removal efficiency reached 95.25% and the concentration of Cl− remaining in the electrolyte was reduced to 43.96 mg/L. Following the recovery and recycling process, the recycled agent (BiO)2SO4 worked well for Cl− precipitation; subsequently, chloride open this circuit as HCl. In purification process, manganese powder was used to reduce the concentration of Bi3+ that remained in the electrolyte to avoid the introduction of new elements. Thus, the concentration of Bi3+ was reduced from 125.00 mg/L to 1.80 mg/L, and the reduced bismuth could be returned to the transformation and activation of Cl− removal agent process. This entire process involving the main elements in the reactions followed a repeatable procedure, as shown in the schematic, wherein 99.98% of bismuth could be recycled and 95.25% of chloride opened the circuit in the form of HCl.

中文翻译：

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一种利用氯化铋去除硫酸锰电解液中氯离子的清洁生产工艺

摘要 在本研究中，提出了一种以 (BiO)2SO4 作为氯化物去除剂，从 MnSO4 电解液中以 BiOCl 形式沉淀 Cl− 的新型、高效且环保的方法。考察了不同因素对除氯剂的转化和活化、氯化物沉淀、回收和回收以及净化过程的影响。增加 L/S 比可以促进转化和活化，而低温和低 pH 值可以对 Cl− 沉淀产生积极影响。在最佳条件下，氯化物去除效率达到95.25%，电解液中残留的Cl-浓度降至43.96 mg/L。在回收和再循环过程之后，再循环试剂 (BiO)2SO4 对 Cl− 沉淀效果很好；随后，氯化物以 HCl 的形式打开该电路。在净化过程中，锰粉用于降低电解液中残留的 Bi3+ 浓度，以避免引入新元素。因此，Bi3+的浓度从125.00 mg/L降低到1.80 mg/L，还原后的铋可以返回到Cl-去除剂的转化和活化过程中。涉及反应中主要元素的整个过程遵循可重复的程序，如示意图所示，其中 99.98% 的铋可以循环使用，95.25% 的氯化物以 HCl 的形式打开回路。还原的铋可以返回到Cl-去除剂的转化和活化过程中。涉及反应中主要元素的整个过程遵循可重复的程序，如示意图所示，其中 99.98% 的铋可以循环使用，95.25% 的氯化物以 HCl 的形式打开回路。还原的铋可以返回到Cl-去除剂的转化和活化过程中。涉及反应中主要元素的整个过程遵循可重复的程序，如示意图所示，其中 99.98% 的铋可以循环使用，95.25% 的氯化物以 HCl 的形式打开回路。