Title: Selective Extraction and Recovery of Zinc and Iron from Electric Arc Furnace Dust Using Integrated Hydrometallurgical-Pyrometallurgical Processes: Experimental Assessment and Process Optimization
Authors: Muzafarova N.M., Jalolov B.A.
Volume: 9
Issue: 12
Pages: 59-65
Publication Date: 2025/12/28
Abstract:
Electric arc furnace dust (EAFD), a zinc- and iron-rich hazardous by-product of steel manufacturing, presents both environmental challenges and opportunities for resource recovery. Its complex mineralogy-dominated by refractory zinc ferrite (ZnFe?O?) and mixed iron oxides-limits the efficiency of conventional single-route recycling technologies. This study provides a comprehensive assessment of nine hydrometallurgical and pyrometallurgical processes and integrates their findings to develop an optimized hybrid strategy for selective Zn-Fe recovery. Hydrometallurgical results demonstrate that ZnO dissolves readily in acidic media, while ZnFe?O? remains the rate-controlling phase. Sulfation roasting significantly enhances Zn leachability, enabling extraction efficiencies exceeding 95%, whereas ionic liquids such as BmimHSO? provide alternative pathways for partial spinel breakdown. Alkaline zincate electrowinning further expands processing options for chloride-rich residues. Pyrometallurgical investigations reveal that hydrogen-based reduction achieves rapid zinc volatilization at moderate temperatures (~950 °C), while sensible-heat reduction using molten iron and the RecoDust process provide effective upgrading of iron-rich residues. The combined analysis confirms that hybrid flowsheets-incorporating roasting, selective leaching, impurity removal, high-temperature reduction, and electrowinning-surpass the limitations of single-stage systems. Optimization using the Attainable Region (AR) method highlights critical variables influencing performance, including lixiviant concentration, leaching temperature, roasting conditions, and reductant dosage. Overall, the proposed integrated approach achieves >95% Zn recovery and >85% Fe upgrading, offering a sustainable, energy-efficient, and industrially viable solution for the circular processing of EAF dust.