Recovery Indium from Indium-Enriched Cementation and Co-precipitation Simultaneously Fe-As

Abstract

A process for extracting of indium from indium-enriched cementation produced in zinc hydrometallurgy process was investigated by oxygen pressure leaching and normal pressure and oxygen-rich leaching. The indium was leached in sulphuric acid medium, at the same time of iron and arsenic were co-precipitated in the form of FeAsO₄. The conditions of selective leaching were explored in the presence of oxidant (H₂O₂). The experimental results indicated that high efficiency of extracting indium and co-precipitation of iron and arsenic was obtained with the appropriate operation conditions. Which were determined as the initial sulphuric acid concentration of 0.26 mol/L, liquid–solid ratio of 10 mL/g, at 80 °C for 6 h. And in the process controlled the pH between 1.3 and 1.8, the sulphuric acid total amount of 0.75 mol/L and add H₂O₂ of 0.6 mL/g. Under the optimum conditions, the leaching per cent of indium was more than 92%, precipitation per cent of iron and arsenic was more than 58 and 60%. Compared with traditional methods of leaching, this process has the characteristics of low acid consumption high leaching rate of indium and removed simultaneously iron and arsenic.