Electrorefining of a gold-bearing antimony alloy in alkaline xylitol solution

The electrochemical dissolution and electro-deposition of a gold and silver bearing antimony alloy obtained from the smelting of antimony concentrate were investigated in alkaline NaOH/xylitol electrolyte. The results show that the electrochemical antimony dissolution increases with higher temperature, but the relationship between antimony dissolution and NaOH/xylitol/antimony concentration is uncertain. The antimony electro-deposition becomes faster with increasing antimony concentration and temperature，but decreasing xylitol concentration. The effects of NaOH/xylitol/antimony concentration, current density, electrode distance, and electrolyte temperature on the electro-refining of antimony process were studied. Under optimal conditions, the current efficiency was 98.3% and energy consumption was 436.7 kwh/t-Sb. The purity of electrolytic antimony was 99.4% and gold and silver were enriched 8–9 times in the anode slime, therefore providing an effective separation of precious metals from antimony by electrolysis.