• A synergistic sulfidation-acid leaching process efficiently recovers Cu, Pb, and Zn from hazardous gypsum residue and zinc-containing fume.
• Thermodynamic calculations and experiments demonstrate high sulfidation rates (81.43% Cu, 88.25% Pb, 92.31% Zn) under optimized roasting conditions.
• Selective acid leaching retains sulfides in the residue while achieving very low leaching rates of Cu, Pb, and Zn (1.94%, 2.05%, 1.51%), enabling metal enrichment.
• This approach offers a clean, economical, and synergistic disposal method for two industrial solid wastes, contributing to sustainable resource recovery.