Zhang Erjun, Zhou Kanggen, Zhang Xuekai, Peng Changhong, Chen Wei, He Dewen
School of Metallurgy and Environment, Central South University Changsha 410083 China
College of Chemistry and Chemical Engineering, Central South University Changsha 410083 China.
RSC Adv. 2021 Jun 28;11(36):22426-22432. doi: 10.1039/d1ra03270d. eCollection 2021 Jun 21.
As, Cu, and Zn rich leaching liquor is generated in the leaching process of copper dust, which contains various metals with high recovery value. Herein, an approach for the direct separation and recovery of arsenic from As, Cu, and Zn rich leaching liquor was proposed. The approach includes two steps, namely SO reduction and arsenic crystallization. The factors affecting the reduction of As(v) to As(iii) were investigated, including the pH, SO dosage, and reduction temperature. In the crystallization stage, the impacts of sulfuric acid consumption and temperature on the crystallization of arsenic (AsO) were studied. The results show that the optimal H concentration, temperature, and SO input for the arsenic reduction were 3.95 mol L, 45 °C, and 1.14 L g As(v), respectively. While the optimal temperature and sulfuric acid dosage in As recovery process were 5 °C and 0.1 L L leaching liquor, respectively. Under these conditions, the AsO recovery percentage reached 96.53%, and the losses of Cu and Zn were only 3.12% and 0.75%, respectively. The precipitate contained 96.72% of AsO, 0.83% of Cu, and 0.13% Zn. Compared with the traditional technologies, this new method can improve the recovery efficiency of AsO and reduce the loss percentage of other valuable metals (Cu and Zn).
在铜烟灰浸出过程中会产生富含砷、铜和锌的浸出液，其中含有多种具有高回收价值的金属。在此，提出了一种从富含砷、铜和锌的浸出液中直接分离和回收砷的方法。该方法包括两个步骤，即二氧化硫还原和砷结晶。研究了影响五价砷还原为三价砷的因素，包括pH值、二氧化硫用量和还原温度。在结晶阶段，研究了硫酸消耗和温度对砷（亚砷酸）结晶的影响。结果表明，砷还原的最佳氢离子浓度、温度和二氧化硫投入量分别为3.95 mol/L、45℃和1.14 L/g五价砷。而砷回收过程中的最佳温度和硫酸用量分别为5℃和0.1 L/L浸出液。在此条件下，亚砷酸的回收率达到96.53%，铜和锌的损失率分别仅为3.12%和0.75%。沉淀物中含有96.72%的亚砷酸、0.83%的铜和0.13%的锌。与传统技术相比，这种新方法可以提高亚砷酸的回收效率，并降低其他有价金属（铜和锌）的损失率。
