Exploring electrohydraulic fragmentation for processing electric arc furnace slags

Electric arc furnace slags (EAFS) are steelmaking by-products rich in valuable metals such as Fe, Mn and Cr. As the steel industry moves towards decarbonization and increases the use of electric arc furnaces, the generation of EAFS is expected to rise, highlighting the need for efficient metal recovery to support waste reduction and circular economy goals. Conventional mechanical processing methods often cannot effectively separate metals from other slag components. This study conducted geochemical, mineralogical, and structural characterization of EAFS to assess the suitability of electrohydraulic fragmentation (EHF) for processing. Mineral Liberation Analysis (MLA) results showed that EAFS comprises finely intergrown magnetic, Fe-rich oxide phases and non-magnetic, Ca-rich oxide and silicate phases with mean grain sizes of <60 µm. EHF was applied to enhance the liberation of metal phases, followed by sieving and magnetic separation. EHF effectively liberated granular metal components in coarse grain fractions (>1 mm), while chemical analysis found no significant enrichment of Fe in magnetic fractions for smaller grain sizes. The findings indicate that combining EHF with sieving and magnetic separation may effectively enhance metal recovery from EAFS. This integrated approach offers a promising method for recycling slag waste and contributes to sustainable practices in the steel industry.