The role of trivalent arsenic in removal of antimony and bismuth impurities from copper electrolytes

The effect of trivalent arsenic on the removal mechanism of antimony and bismuth from copper electrolyte was investigated. The electrolyte was filtered and the precipitate structure, morphology and composition were analyzed by means of chemical analysis, scanning electron microscopy, transmission electron microscopy, energy dispersive spectra, X-ray diffraction, and infrared spectroscopy. The precipitate in the form of fine spherical particles mainly consists of As, Sb, Bi and O elements. The characteristic bands in the IR spectra of the precipitate are O–H, As–OH, As–OX (X = As, Sb), As–O–Sb, Sb–OY (Y = As, Sb, Bi) and O–As–O. The precipitate is a mixture of microcrystalline (Sb, As)2O3, BiSb2O7, and an amorphous phase. The impurities of Sb and Bi are effectively removed from copper electrolytes by trivalent arsenic owing to these precipitates.

► As (III) ion plays important role in Sb and Bi removal from copper electrolyte.
► Structure of precipitate obtained with As (III), Sb and Bi was characterized.
► Removal of Sb and Bi by As (III) ascribes to (Sb, As)2O3, BiSb2O7 and amorphous phase.