Removal of organic matter in germanium precipitated solution by modified anode slime

Germanium precipitation with tannic is widely used to recover low concentration germanium from zinc hydrometallurgy solution. However, the amount of organic matter introduced by this process is large, which seriously affects the efficient operation of zinc hydrometallurgy system. Therefore, with the help of TOC, FT-IR, XRD, UV-vis, and other characterization methods, the removal effect of modified anode slime on the organic matter in the germanium precipitated solution was investigated, and then the reaction mechanism was revealed. The results show that the modified anode slime obtained from the activation of anode slime at a temperature of 80 ℃ and a sulfuric acid dosage of 14 mL/100 g has a good removal effect of the organic matter in the germanium precipitated solution. When the amount of anode slime is 20 g/L, the TOC removal rate can reach 66.17%, and the TOC concentration in the reaction solution can be reduced to 58.21 mg/L. This effect is related to the conversion of inert α-MnO₂ into highly active MnOOH in the anode slime during the modification process, and the amount of sulfuric acid and temperature have a significant influence on the modification effect of anode slime. The main organic substances in germanium precipitated solution are tannic acid and its derivatives. After the treatment with modified anode slime, the tannic acid in the solution after germanium precipitation undergoes incomplete degradation, and the degradation products are mainly small molecular weight hydrocarbon organics.