Role of arsenic(V) and bismuth in the recovery of antimony by hydrolysis and precipitation from eluates produced during copper electrorefining

The recovery of antimony from side stream is challenging due to impurities like arsenic and bismuth which affect extraction efficiency and product quality. This study examines the individual and combined effects of As and Bi on antimony hydrolysis from eluates produced during copper electrorefining. Synthetic and process eluates were analysed to optimise operating conditions and understand impurity interactions. Hydrolysis experiments across pH values (0.25–0.9) revealed an optimal pH range (0.6–0.7) for maximizing antimony recovery (>90 %) in impurity-free conditions. Arsenic reduced the antimony recovery by 8 %–13 %, destabilising precipitates and forming amorphous phases. Bismuth caused a smaller reduction (3 %–7 %) but had a diminished effect in the presence of As, which dominated the system's chemistry. Process eluates exhibited greater variability, particularly in extraction yields, underscoring the need to validate findings based on synthetic solutions against industrial matrices. This study provides insights into optimizing antimony recovery through impurity management and highlights the value of combining the analyses of synthetic and process eluates. • Antimony recovery >90 % achieved at optimal pH range (0.6–0.7) in HCl-Cl-Sb(III) systems. • Arsenic reduces recovery by 8–13 %, disrupting crystallinity and forming amorphous phases. • Bismuth causes 3–7 % recovery loss and induces structural distortions in oxychlorides. • Synthetic eluates accurately predict trends, validated by results with industrial eluates. • Process eluates confirm pH (0.6–0.7) as key to mitigating impurity effects on recovery.