Role of Sb(V) in removal of As, Sb and Bi impurities from copper electrolyte

The function mechanism of Sb(V) in As, Sb and Bi impurities removal from copper electrolyte was investigated by adding Sb(V) ion in a synthetic copper electrolyte containing 45 g/L Cu2+, 185 g/L H2SO4, 10 g/L As and 0.5 g/L Bi. The electrolyte was filtered, and the precipitate structure, morphology and composition were characterized by chemical analysis, SEM, TEM, EDS, XRD and FTIR. The results show that the precipitate is in the shape of many irregular lumps with size of 50–200 μm, and it mainly consists of As, Sb, Bi and O elements. The main characteristic bands in the FTIR spectra of the precipitate are As—O—As, As—O—Sb, Sb—O—Bi, Sb—O—Sb and Bi—O—Bi. The precipitate is the mixture of microcrystalline of AsSbO4, BiSbO4 and Bi3SbO7 by XRD and electronic diffraction. The removal of As, Sb and Bi impurities by Sb(V) ion can be mainly ascribed to the formation of antimonate in copper electrolytes.