Mineralogical Association of Elements in Electric Arc Furnace Dust: Elemental Deportment, Phase Hosts, and Metallurgical Implications—A Critical Review

Electric arc furnace dust (EAFD) is a multielement, multiphase residue whose response to mineral processing and metallurgical treatment cannot be predicted from bulk assays alone. This thematic critical review evaluates the allocation of Zn, Fe, Pb, Cd, Cr, Mn, Ni, alkaline-earth elements, silicates, halogens, and sulfur among crystalline, poorly crystalline, amorphous, and surface-associated hosts. The proposed chain of evidence distinguishes phase abundance, elemental deportment, oxidation state, particle architecture, intrinsic phase reactivity, geometric accessibility, and measured process response. Quantitative deportment, independent elemental closure, and explicitly unassigned inventory are recommended instead of forced stoichiometric assignment. Comparisons of exposed ZnO, substituted Zn-bearing spinels, and enclosed Zn-bearing grains show why intrinsic chemical resistance must be distinguished from transport limitations caused by encapsulation. Correlative diffraction, electron microscopy, microanalysis, spectroscopy, and before–after process balances support evidence-gated treatment screening without treating selective extraction as unique mineral identification. The principal limitation remains incomplete cross-feedstock validation of phase-resolved behavior.