Metal Recovery from Sintering Dust: Process Performance and Environmental Trade-Offs

Sintering dust is a high-salinity solid waste generated during iron ore sintering, containing recoverable resources such as Fe, K, Na, Pb, Zn, and Ag, while also accumulating potentially hazardous components including Cl, Tl, Cd, and As. This review provides a comprehensive evaluation of the physicochemical properties of sintering dust and critically examines the application of hydrometallurgical, pyrometallurgical, and integrated hydrometallurgical–pyrometallurgical processes for resource recovery. Representative recovery technologies for K, Ag, Pb, Zn, and Fe are systematically summarized, with their respective merits, limitations, and environmental trade-offs comparatively analyzed. Hydrometallurgical processes exhibit notable efficacy in the selective extraction of soluble salts and valuable metals, yet they require rigorous management of high-salinity wastewater and metal-bearing residues. Pyrometallurgical processes facilitate the large-scale recovery of iron and volatile metals, but they demand stringent control of energy consumption, gaseous emissions, and secondary pollution. It is worth noting that most current research on sintering dust processing remains at the laboratory stage, with limited industrial-scale validation. Future research should transition from the recovery of single elements toward a coupled approach that integrates selective hydrometallurgical leaching with deep pyrometallurgical enrichment, thereby enabling stepwise, multielement extraction. This synergistic strategy allows for superior elemental separation and the comprehensive valorization of all constituents through the complementarity of selective enrichment and targeted extraction.