Steelmaking dust (EAF Dust): composition, environmental challenges and advances in recovery technologies

Electric Arc Furnace Dust (EAFD) is a hazardous by-product of steelmaking with significant environmental and economic relevance due to its high content of zinc, iron, and toxic heavy metals such as lead, cadmium, and chromium. This review provides a comprehensive overview of EAFD generation, physicochemical composition, regulatory classification, and current treatment technologies. The dust typically contains 25–50 wt.% iron and 5–40 wt.% zinc, mainly as Fe₃O₄, Fe₂O₃, ZnO, and ZnFe₂O₄, the latter posing challenges for leaching due to its refractory nature. Treatment options discussed include pyrometallurgy (e.g., Waelz process), hydrometallurgy, stabilization/solidification, and emerging alternatives such as oxygen-assisted chlorination, bioleaching, and electrochemical recovery. Comparative analysis reveals trade-offs between metal recovery, energy demand, residue generation, and environmental impact. While the Waelz process remains the most widely applied, innovative hybrid and low-carbon processes are gaining attention for their selectivity and sustainability. The review emphasizes the importance of process integration, reagent recycling, and life cycle assessment to support the circular recovery of valuable metals from EAF dust.