Innovative Solvent Extraction Processes for the Separation of Indium, Germanium, and Gallium from Iron

GermaniumGermanium, galliumGallium, and indiumIndium are valuable elements due to their great economic importance and growing utilization in high-tech and green-tech applications. The exploitation of secondary resourcesSecondary resource, for example, tailings, slags, or end-of-life products, as well as the application of sustainableSustainable biotechnological methods, results in the challenge of separating Fe(III) from In(III), Ge(IV), or Ga(III). With common methods, such as precipitation, the selectivitySelectivity for In, Ga, and Ge is often insufficient. The application of innovative solvent extractionSolvent extraction processes is a promising approach to separate valuable metals from iron in order to make them available for an efficient recoveryRecovery. In this study, we present the development of extraction methods using amine extractantsAmine extractants for the selective separation of Fe(III) from In(III), Ga(III), and Ge(IV) in sulphate solutions. The influence of different parameters, e.g. the pH value and the composition of the organic phase, as well as possibilities to re-extract iron from the loaded organic phase, will be discussed.