(昆明理工大学 冶金与能源工程学院,昆明 650093)
摘 要: 锌冶炼浸出渣中锌主要以铁酸锌的形式存在,针对锌浸渣中铁酸锌难于分解的问题,以铁酸锌作为研究对象,研究二氧化硫作用下铁酸锌中锌的溶出和Fe(Ⅲ)的还原行为。考察初始硫酸浓度、液固比、二氧化硫通入量、反应时间、反应温度对二氧化硫还原分解铁酸锌行为的影响。结果表明:最佳反应条件如下,初始硫酸浓度120 g/L、液固比11:1、二氧化硫通入量0.41×10-2 mol/g、反应时间120 min、反应温度105 ℃。在最佳反应条件下,对锌浸渣开展还原浸出实验,锌的浸出率能达到99%以上,Fe(Ⅲ)的还原率能达到98%。通过ICP-MS和XRD分析表明,锌浸渣中的铁酸锌完全分解,还原浸出渣的主要成分为锌和铅,分别以ZnS和PbSO4的形式存在。
关键字: 铁酸锌;锌浸渣;二氧化硫;浸出
(Faculty of Metallurgical and Energy Engineering, Kunming University of Science and Technology, Kunming 650093, China)
Abstract:The zinc in zinc residues exists mainly as zinc ferrite, in order to solve the difficulty of decompose zinc ferrite in zinc residues, by taking a zinc ferrite as the research object, the dissolution of zinc and the reduction of Fe(Ⅲ) in zinc ferrite under the action of sulfur dioxide were investigated. The effects of initial sulfuric acid concentration, liquid solid ratio, sulfur dioxide content, reaction time and reaction temperature on the reductive decomposition of zinc ferrite were studied when sulfur dioxide was used as reductant. The results show that the optimal reaction condition are as follows: sulfuric acid concentration of 120 g/L, liquid-solid ratio of 11:1, SO2 intake of 0.41×10-2 mol/g , reaction time of 120 min and reaction temperature of 105 ℃. The leaching rate of zinc is as high as 99% and the reduction rate of Fe(Ⅲ) is 98% under the optimum reaction conditions. Furthermore, the zinc ferrite is fully decomposed, and the main compositions of the residue are ZnS and PbSO4, according to the ICP-MS and XRD analysis.
Key words: zinc ferrite; zinc residues; sulfur dioxide; leaching