A Review on the Recovery of Noble Metals from Anode Slimes

Anode slimes resulting from the electrorefining of Cu, Pb, Sn, and Zn contain noble metals, such as Au, Ag, and platinum group metals. Pretreatments have been employed to enrich the noble metals by removing base metals from the anode slimes. The enriched residues are dissolved in diverse aqueous systems such as cyanide, thiosulfate, thiourea, and halide in the presence/absence of oxidizing agents. Separation of noble metals from the solution depends on the nature of the leaching solutions. Solvent extraction, ion exchange, electrowinning, and some novel technologies are employed for the separation. The advantages and disadvantages of each separation process were reviewed. Moreover, new materials for the separation of noble metals have been introduced.