Abstract The first two-stage zinc pressure leaching plant with 100 kt-Zn/a capacity in China was put into production in 2009, to recover zinc, rare metals, germanium and gallium. However, the total extraction of zinc is limited to just 93% in initial production. To improve the co-recovery of metals, pressure leaching tests were carried out on the first-stage leach residue from the initial flowsheet. The effects of Fe(III) concentration, oxygen partial pressure, reaction time, sulfuric acid dosage, and particle size of the residues were investigated. The results showed that particle size and acid dosage greatly affected the zinc, iron, gallium, and germanium extraction. The particles of size above 74 μm are the main obstacles to improve extraction. Grinding can effectively improve the recovery of the main metals. The zinc extraction can reach 96.7% after grinding the coarse particles (> 74 μm) prior to leaching. The extraction of other metals are 84.7%, 81.7% and 81.4% for iron, gallium, and germanium, respectively. The total recovery of the two-stage leaching is 98.2%, 90.0%, 86.3% and 87.8% for zinc, iron, gallium, and germanium, respectively.

中文翻译：

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锌加压浸出工艺的提取改进研究

摘要 2009年，国内首座100kt-Zn/a产能的二段式锌压浸装置投产，回收锌、稀有金属、锗和镓。然而，在初始生产中，锌的总提取量仅限于 93%。为了改善金属的共同回收，对初始流程中的第一阶段浸出残渣进行了压力浸出试验。研究了 Fe(III) 浓度、氧分压、反应时间、硫酸用量和残留物粒度的影响。结果表明，粒径和酸用量对锌、铁、镓和锗的提取有很大影响。尺寸超过 74 μm 的颗粒是提高萃取率的主要障碍。研磨可有效提高主要金属的回收率。锌提取率可达96。浸出前研磨粗颗粒 (> 74 μm) 后的 7%。其他金属的提取率分别为铁、镓和锗的84.7%、81.7%和81.4%。两段浸出的锌、铁、镓和锗的总回收率分别为98.2%、90.0%、86.3%和87.8%。