Germanium plays an essential role in many high-tech fields because of its excellent electrical and optical properties. As a zinc refining by-product, zinc oxide dust (ZOD) is one of the most important sources of germanium recovery. However, the low leaching efficiency of germanium seriously hinders germanium recovery. This study focuses on the phase evolution and elemental distribution of zinc and germanium during the zinc refining process by analyzing the occurrence state of zinc and germanium in products and the key factors and chemical reactions causing the loss of zinc and germanium during the process. In the sulfuric-acid leaching process without an oxidant, the sulfides encapsulating germanium cannot be leached, which resulted in a loss of germanium. In addition, the formation of an insoluble PbSO4 coating layer and silica compounds during the sulfuric-acid leaching impeded the leaching reactions. Accordingly, pre-treatment by oxidative leaching with Fe3+ and the role of NaAc in dissolving PbSO4 were tested. The efficiency of Ge recovery is approximately 30 % higher than that of the conventional leaching process.

中文翻译：

---

锌和锗在硫化物焙烧、锌发烟和浸出过程中的相演变和元素分布：预处理氧化锌粉尘的好处


锗因其优异的电学和光学性能，在许多高科技领域发挥着至关重要的作用。作为锌精炼的副产品，氧化锌粉尘 （ZOD） 是锗回收的最重要来源之一。然而，锗的低浸出效率严重阻碍了锗的回收。本研究通过分析锌和锗在产品中的存在状态以及在此过程中导致锌和锗损失的关键因素和化学反应，重点研究了锌和锗在精炼过程中的相演化和元素分布。在没有氧化剂的硫酸浸出过程中，包裹锗的硫化物无法浸出，从而导致锗的损失。此外，硫酸浸出过程中不溶性 PbSO4 涂层和二氧化硅化合物的形成阻碍了浸出反应。因此，测试了 Fe3+ 氧化浸出的预处理以及 NaAc 在溶解 PbSO4 中的作用。锗的回收效率比传统浸出工艺高约 30%。