(1. 中南大学 资源加工与生物工程学院，长沙 410083；
2. 中南大学 冶金与环境学院，长沙 410083)
摘 要: 采用还原焙烧将高铁锌焙砂中的铁酸锌选择性地分解为氧化锌和磁铁矿，再通过两段浸出工艺回收锌，以实现锌铁分离和获得以磁铁矿为主的浸出渣。主要考察了还原焙烧、中性浸出及低酸浸出条件对锌焙砂中锌、铁浸出率的影响。结果表明：通过还原焙烧可以显著地提高锌焙砂的锌浸出率；中性浸出的最佳条件为浸出温度60 ℃、液固比10:1、初始酸度45 g/L和浸出时间2 h；低酸浸出的最佳条件为浸出温度70 ℃、液固比10:1、初始酸度60 g/L、搅拌速度300 r/min和浸出时间2 h。在最佳条件下，两段浸出的总锌浸出率约为90%，总铁浸出率约为5%。经XRD和SEM/EDS分析，浸出渣以磁铁矿为主，其次是闪锌矿和铁酸锌；铁酸锌存在的主要原因是在还原焙烧过程中被氧化锌等矿物包裹，使其分解不充分。
关键字: 高铁锌焙砂；铁酸锌；还原焙烧；浸出
（1. School of Minerals Processing and Bioengineering, Central South University, Changsha 410083, China;
2. School of Metallurgy and Environment, Central South University, Changsha 410083, China）
Abstract:Based on the decomposition of zinc ferrite to ZnO and Fe3O4 by reduction roasting, the recovery of zinc from the roasted zinc calcine was studied by two-stage leaching for zinc-iron separation and the leaching residue containing Fe3O4 was obtained. The effects of reduction roasting and conditions of neutral leaching and acid leaching on leaching rates of zinc and iron were investigated, respectively. The results show that the reduction roasting has a significant effect on recovery of zinc, and the leaching rates of Zn and Fe are about 90% and 5%, respectively. Under the following optimum conditions, which are leaching temperature of 60 ℃, liquid/solid ratio of 10:1, acid concentration of 45 g/L and leaching time of 2 h for neutral leaching, and leaching temperature of 70 ℃, liquid/solid ratio of 10:1, acid concentration of 60 g/L, stirring speed of 300 r/min and leaching time of 2 h for acid leaching. Besides, the main compositions of the residue are Fe3O4, ZnS and ZnFe2O4 according to the XRD and SEM/EDS analysis. The main reason of zinc ferrite left is attributed to the enclosure by other minerals.
Key words: high iron-bearing zinc calcine; zinc ferrite; reduction roasting; leaching
