Germanium and indium are considered by many economies as critical raw materials. Therefore, investigation on possible methods of selective extraction of these elements from natural sources is getting increasing attention. The paper presents the results of solvent extraction tests of real sulphate solution obtained by leaching of dross and containing 5.15 g/dm³ Ge, 1.52 g/dm³ In and 5.81 g/dm³ Zn. In the first stage initial solution was doped with tartaric acid (citric and ascorbic acid were also tested) and germanium was extracted with trioctylamine(TOA)-tributyl phosphate (TBP) system. It was found that addition of complexing agent was necessary to achieve germanium extraction with TOA. Then, germanium was stripped with sodium hydroxide solution. Germanium extraction yield was >99%, while its stripping yield was 66–69%. Moreover, indium and zinc extraction yields were < 1%, therefore the operation was very selective. Additionally, it was found that stripping may be performed only if NaOH concentration was in the range between 10 and 20%. The reason was precipitation of germanium from aqueous phase at low NaOH (<10%) concentrations and formation of third phase and emulsion at higher NaOH levels (>20%). In the second stage, indium was recovered from the raffinate obtained after germanium extraction. Di-(2-ethylhexyl) phosphoric acid (DEHPA/D2EHPA) was used as an extractant and hydrochloric acid as a strippant. Indium extraction and stripping yields were > 98%, while zinc extraction yield was <1% allowing selective separation of In form Zn. It was found that solvent extraction using investigated system (3-stage germanium extraction, 3-stage germanium stripping, 2-stage indium extraction and 2-stage indium stripping) may be applied for selective recovery of germanium and indium.

锗和铟被许多经济体视为重要原材料。因此，对从天然资源中选择性提取这些元素的可能方法的研究日益受到关注。本文介绍了通过浸出浮渣得到的，含5.15 g / dm ³ Ge，1.52 g / dm ³ In和5.81 g / dm ³的真实硫酸盐溶液的溶剂萃取测试结果。锌 在第一阶段中，初始溶液中掺入酒石酸（还测试了柠檬酸和抗坏血酸），并用三辛胺（TOA）-磷酸三丁酯（TBP）系统萃取锗。发现添加络合剂对于用TOA实现锗萃取是必要的。然后，用氢氧化钠溶液汽提锗。锗提取率> 99％，而汽提率则为66-69％。此外，铟和锌的提取产率＜1％，因此操作非常有选择性。另外，发现仅当NaOH浓度在10％和20％之间的范围内时才可以进行汽提。原因是锗在低NaOH（<10％）浓度下从水相中沉淀出来，并在更高NaOH浓度（> 20％）时形成了第三相和乳液。在第二阶段 从萃取锗后得到的萃余液中回收铟。使用二（2-乙基己基）磷酸（DEHPA / D2EHPA）作为萃取剂，并使用盐酸作为汽提剂。铟提取和汽提产率> 98％，而锌提取率<1％，可以选择性分离In形式的Zn。已发现使用研究的系统（3阶段锗萃取，3阶段锗汽提，2阶段铟萃取和2阶段铟汽提）进行溶剂萃取可用于选择性回收锗和铟。1％允许选择性分离In形式的Zn。已发现使用研究的系统（3阶段锗萃取，3阶段锗汽提，2阶段铟萃取和2阶段铟汽提）进行溶剂萃取可用于选择性回收锗和铟。1％允许选择性分离In形式的Zn。已发现使用研究的系统（3阶段锗萃取，3阶段锗汽提，2阶段铟萃取和2阶段铟汽提）进行溶剂萃取可用于选择性回收锗和铟。