Processing of Zinc Production Wastes and Recycling Opportunities
Abstract
The generation of large volumes of waste during zinc production represents both an environmental challenge and a valuable secondary resource for metal recovery. This study investigates the physicochemical and mineralogical characteristics of zinc-containing wastes and evaluates effective processing routes for improving zinc extraction efficiency. Special attention is given to zinc ferrite (ZnFe₂O₄), which is the dominant refractory phase in zinc cake and significantly limits conventional hydrometallurgical recovery. SEM-EDX and mineralogical analysis confirm that the material is a complex multi-phase system composed mainly of Zn, Fe, O, and S, with minor amounts of Pb, Cu, Cd, Ca, and Si. The proposed processing strategy involves lime-assisted roasting followed by sulfuric acid leaching under optimized conditions. Thermodynamic considerations and experimental evidence indicate that this combined approach significantly enhances zinc dissolution compared to conventional direct leaching methods. The results demonstrate that integrated pyrometallurgical–hydrometallurgical treatment of zinc production wastes can improve metal recovery efficiency, reduce environmental impact, and support sustainable resource utilization in non-ferrous metallurgy.