Wang Gui-Hua, DU Pei-Pei, Zhang Liang-Jin, Long Yue, Zhang Jian-Song
College of Metallurgy and Energy, North China University of Science and Technology, Tangshan, 063210, Hebei, China.
Key Laboratory of Modern Metallurgical Technology of the Ministry of Education, North China University of Science and Technology, Tangshan, 063210, Hebei, China.
Sci Rep. 2024 Dec 3;14(1):30153. doi: 10.1038/s41598-024-81667-6.
Secondary zinc oxide dust is rich in high-grade metals such as Zn, In, Pb, and Ga, and in the face of the depletion of ore resources at home and abroad, it is of great significance to seek an efficient process to realize the full resource recovery of valuable metals in secondary zinc oxide dust. In this study, on the basis of the thermodynamic analysis of the wet treatment process, three wet treatment methods, namely "low acid leaching", "high acid leaching" and "chlorination leaching", were used to explore the suitable parameters for stepwise extraction of Zn, In and Pb metals. The results showed that the three wet treatment methods could effectively extract the corresponding main elements, and the optimal leaching rates of Zn, In and Pb were 73, 90 and 94%, respectively. Thermodynamic analysis shows that under ideal conditions, the "cascade separation" of some or all metals can be theoretically achieved by using a suitable leaching solvent for zinc oxide dust. The concentration of sulfuric acid, the ratio of liquid solid volume to mass and temperature had great effects on the leaching rate of Zn and In, and the leaching rate of Zn and In also increased with the increase of the values of the three experimental parameters, which was positively correlated. The leaching rate of Pb will increase with the increase of sulfuric acid concentration, but when the pH of the solution system is < 2, Pb will form PbSO precipitate, which inhibits the leaching ability of Pb. In the chlorinated leaching system with "ammonium chloride + hydrochloric acid" as the leaching solvent, the excess Cl and Pb fully coordinated to promote the efficient leaching of Pb metal, and the initial pH value of the solution had a great influence on the Leaching Rate of Pb. The multi-stage combined wet treatment process is an effective solution to realize the full quantitative recovery of valuable elements in Secondary zinc oxide dust, In this paper, the suitable process conditions for stepwise extraction of Zn, In and Pb metals were obtained through wet treatment experiments, and the cascade separation of metals in zinc oxide dust was preliminarily realized, which provided an important idea for the efficient utilization of metallurgical dust and sludge solid wastes, and at the same time provided theoretical support for the industrial practice of recycling valuable elements in metallurgical dust.
二次氧化锌粉尘富含锌、铟、铅、镓等高品位金属，面对国内外矿石资源的枯竭，寻求一种高效工艺以实现二次氧化锌粉尘中有价金属的全资源回收具有重要意义。本研究在湿法处理工艺热力学分析的基础上，采用“低酸浸出”“高酸浸出”和“氯化浸出”三种湿法处理方法，探索分步提取锌、铟、铅金属的适宜参数。结果表明，三种湿法处理方法均可有效提取相应主要元素，锌、铟、铅的最佳浸出率分别为73%、90%和94%。热力学分析表明，在理想条件下，通过使用合适的氧化锌粉尘浸出溶剂，理论上可实现部分或全部金属的“梯级分离”。硫酸浓度、液固体积质量比和温度对锌和铟的浸出率影响较大，锌和铟的浸出率也随这三个实验参数值的增加而增加，呈正相关。铅的浸出率会随硫酸浓度的增加而增加，但当溶液体系pH＜2时，铅会形成硫酸铅沉淀，抑制铅的浸出能力。在以“氯化铵+盐酸”为浸出溶剂的氯化浸出体系中，过量的氯离子与铅充分配位，促进了铅金属的高效浸出，溶液的初始pH值对铅的浸出率影响较大。多级联合湿法处理工艺是实现二次氧化锌粉尘中有价元素全量回收的有效解决方案，本文通过湿法处理实验获得了分步提取锌、铟、铅金属的适宜工艺条件，初步实现了氧化锌粉尘中金属的梯级分离，为冶金粉尘和污泥固体废物的高效利用提供了重要思路，同时为冶金粉尘中有价元素回收的工业实践提供了理论支持。
