Process for selective liquid-liquid extraction of germanium

A process for selective liquid-liquid extraction of germanium from an aqueous acidic liquor containing, besides germanium, at least one other metal selected from the group consisting of cadmium, cobalt and nickel, said process comprising,

• adjusting the pH of said aqueous liquor to a value lower than 2 before extracting germanium from said aqueous liquor,
• extracting germanium from said aqueous liquor by contacting said liquor with an organic medium which contains a diluent and an extractant, said diluent being immiscible with said aqueous liquor, said extractant being an oxine derivative having a long hydrocarbon chain containing 8 to 16 carbon atoms, said extracting step forming an aqueous phase containing the major part of said at least one other metal and an organic phase containing the major part of germanium from said aqueous liquor, and
• stripping germanium from said organic phase by contacting said phase with an alkaline medium, said stripping step forming an aqueous phase containing the major part of germanium from said aqueous liquor and an organic phase containing said diluent and said extractant.