Iron recovery from electric arc furnace slag: Characterisation and optimisation of magnetic separation

Electric Arc Furnace (EAF) steelmaking slag is an industrial by-product containing significant iron and other valuable elements. This study investigated slag from Mobarakeh Steel Company to characterise its chemical and mineralogical properties, optimise grinding and evaluate iron recovery by magnetic separation. Chemical analysis indicated 27.01% total iron (20.78% Fe²⁺, 5.33% Fe³⁺ and 0.90% metallic Fe). XRD identified wüstite, magnetite, merwinite and gehlenite as dominant minerals. Optical microscopy and SEM–EDS showed that magnetite and metallic iron are finely interlocked with silicate gangue, limiting liberation. Ball-mill grinding reduced d80 from 870 to 77 µm. Magnetic separation revealed that wet separation at 1700 G for 77 µm particles was optimal, increasing the iron grade to 49.20%. The results highlight the potential of combined grinding and magnetic separation for efficient iron recovery from EAF slag.