Owing to the characteristics of mineral paragenesis (equilibrium sequence of mineral phases), the hydrochloric acid leach liquors of Sn ores and Sn-containing waste materials typically contain large amounts of Pb. In this study, barium sulfate coprecipitation was employed to efficiently remove Pb from a tin chloride solution. The lead removal efficiency, reaction mechanism, and limitations were investigated by varying the Cl and SO concentrations. The results showed that the structural formula of the precipitates was (BaPb)(SO) (x + y = 2), and its solubility product was in the range of 1 × 10–1 × 10, indicating that Pb and Ba were more easily precipitated in the form of complex salts. In addition, thermodynamic analysis revealed that when the Cl concentration was <1 mol/L in the Pb–Sn–Cl–HO system, [Pb] and [PbCl] were the primary species. These positively charged species were readily adsorbed onto the surface of BaSO via electrostatic forces, resulting in a significant increase in the Pb content of (BaPb)(SO). Therefore, the Pb removal efficiency significantly improved as Cl concentration decreased. The lead removal mechanism involves a combination of adsorption and replacement processes. Based on the aforementioned fundamental study, a method involving dechlorination and coprecipitation was proposed to remove lead from an acid leaching solution of Kaldo slag. With the dechlorination via distillation, the Pb removal efficiency could reach 99.9% at 1 mol/L Cl and 0.5 mol/L SO.

中文翻译：

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硫酸钡和(BaxPby)(SO4)2共沉淀法去除氯化锡溶液中的铅用于处理Pb[sbnd]Sn冶炼炉渣


由于矿物共生（矿相平衡序列）的特点，锡矿石和含锡废料的盐酸浸出液通常含有大量的Pb。在这项研究中，采用硫酸钡共沉淀法有效去除氯化锡溶液中的铅。通过改变 Cl 和 SO 浓度来研究铅的去除效率、反应机制和局限性。结果表明，沉淀物的结构式为(BaPb)(SO)(x+y=2)，其溶度积在1×10~1×10范围内，表明Pb和Ba更容易析出。以复盐形式沉淀。此外，热力学分析表明，当 Pb-Sn-Cl-H2O 体系中 Cl 浓度<1 mol/L 时，[Pb] 和 [PbCl] 是主要物种。这些带正电的物质很容易通过静电力吸附到 BaSO 的表面，导致 (BaPb)(SO) 的 Pb 含量显着增加。因此，随着Cl浓度的降低，Pb去除效率显着提高。除铅机制涉及吸附和置换过程的结合。基于上述基础研究，提出了一种脱氯共沉淀法去除卡尔多渣酸浸液中的铅。通过蒸馏脱氯，在1 mol/L Cl和0.5 mol/L SO时，Pb去除率可以达到99.9%。