ABSTRACT

Zinc leaching residue is an important secondary sources of zinc. To realize recycling utilization of this zinc secondary resource, a novel technology is proposed for the recovery of zinc from the zinc leaching residue by the bottom-blown reduction process in this study. The effects of reduction temperature, reduction time, coal rate, and lime addition on the metal content in the slag and the volatilization rate of lead and zinc during reduction were evaluated. The optimized conditions for the recovery of Pb and Zn in the bottom-blown reduction process were determined as 1473 K with a coal rate of 35% and a lime addition of 4% for a reduction time of 70 min. Under the optimized conditions, the recovery rate of Pb and Zn is over 90% and 94%, respectively. The lead, zinc, and copper content in the reduced slag is 0.15%, 0.7%, and 0.07%, respectively. An industrial test was carried out for the recovery of Pb and Zn from the zinc leaching residue by bottom-blown reduction, resulting in a ZnO content of less than 3% in the reduced slag and a coal rate of 35%, not less than 0.6 for CaO/SiO₂ (mass ratio) and 1.0 ~ 1.2 for FeO/SiO₂ (mass ratio).

摘要

锌浸出渣是锌的重要二次来源。为了实现这种锌二次资源的循环利用，本研究提出了一种通过底吹还原工艺从锌浸出渣中回收锌的新技术。评价了还原温度、还原时间、煤量和石灰添加量对炉渣中金属含量和还原过程中铅锌挥发率的影响。底吹还原法回收Pb和Zn的优化条件确定为1473 K，煤率为35%，石灰添加量为4%，还原时间为70 min。在优化条件下，Pb和Zn的回收率分别超过90%和94%。还原渣中铅、锌、铜的含量分别为0.15%、0.7%和0.07%。₂ (质量比) 和 1.0 ~ 1.2 FeO/SiO ₂ (质量比)。