In this study, hydrometallurgical processes involving pressure acid leaching and solvent extraction were developed to aid recovery of indium from zinc slag, which is produced in the imperial smelting process. Four different acid leaching methods were studied, namely atmospheric leaching, atmospheric leaching with KMnO₄, roasting-atmospheric leaching, and oxygen pressure leaching in a sulfuric acid medium. Oxygen pressure acid leaching is the most effective method for indium extraction, and 94.1% of indium was leached under the optimum conditions, i.e., 300 g/L H₂SO₄,oxygen pressure 0.4 MPa, liquid/solid ratio 10 mL/g, and temperature 100°C for 5 h. X-ray diffraction and scanning electron microscopy examination of the raw material and leaching residue samples indicated that the intermetallic compounds Cu₅Zn₈and Cu₂Zn, metallic zinc, and iron in the raw material dissolved, leaving the insoluble components PbSO₄ and Pb as the major compounds in the leaching residue. A 98.5% proportion of the indium in the leaching solution was selectively extracted with 30% bis(2-ethylhexyl) phosphate and 70% kerosene by three-stage counter-current extraction, and 99.5% of the indium in the loaded organic phase was stripped by 6 mol/L HCl through four-stage counter-current stripping. The overall recovery yield of indium through all processes was approximately 92%.

在这项研究中，开发了涉及加压酸浸和溶剂萃取的湿法冶金工艺，以帮助从帝国冶炼过程中产生的锌渣中回收铟。研究了四种不同的酸浸方法，即大气浸提，KMnO ₄大气浸提，焙烧-大气浸提和在硫酸介质中的氧压浸提。氧压酸浸是最有效的铟萃取方法，在最佳条件下（300 g / LH ₂ SO ₄）浸出了94.1％的铟。，氧气压力0.4 MPa，液/固比10 mL / g，温度100°C持续5 h。原料和浸出残留物样品的X射线衍射和扫描电子显微镜检查表明，原料中的金属间化合物Cu ₅ Zn ₈和Cu ₂ Zn，金属锌和铁溶解，剩下不溶性组分PbSO ₄铅是浸出残渣中的主要化合物。通过三阶段逆流萃取，分别用30％的磷酸双（2-乙基己基）酯和70％的煤油选择性萃取浸出溶液中98.5％的铟，并汽提负载有机相中99.5％的铟。通过四级逆流汽提分离出6 mol / L HCl。通过所有过程，铟的总回收率约为92％。