Evaluation of the potential for iron recovery in mining tailings by magnetic separation

Le résumé fourni par la source

• Tailings from the Quadrilátero Ferrífero/MG (17.82% Fe) revalued into a sustainable high-value resource; • Advanced tailing characterization and Fe recovery by high-efficiency magnetic separation; • High-quality Fe concentrate (56.64 %wt) produced from tailings for the metallurgy; • SiO 2 -rich byproduct (90.86%) can substitute sand promoting lower environmental impact; • Solution 2.5x cheaper than implementing mining operations mitigating dam liabilities and risk. The valorization of the vast volumes of iron ore tailings from the Quadrilátero Ferrífero region represents both a critical challenge and a strategic opportunity for the sustainability of the mining sector. This study investigated the potential for high-efficiency iron recovery from these heterogeneous tailings, employing an integrated approach combining magnetic separation, advanced characterization and subsequent quantification. X-ray fluorescence (XRF) analysis confirmed the complex composition of the raw material (Sample 1), characterized by a high SiO₂ content (73.60 wt%) and a Fe₂O₃ content (25.12 wt%), corroborated by gravimetric analysis (GA) showing Fe content (17.82 wt%). X-ray diffraction (XRD) and Mössbauer spectroscopy synergistically mapped the ferriferous phases, identifying hematite and goethite as the main magnetically recoverable minerals, in contrast to the predominant quartz. Magnetic separation demonstrated excellent performance, achieving two simultaneous high-impact outcomes: (i) production of a high-quality iron concentrate (Sample 3) with Fe₂O₃ content (91.13 wt%) by XRF and Fe content (56.64 wt%) by GA, immediately suitable for the metallurgical chain; and (ii) a silica-rich byproduct (Sample 2) with SiO₂ content (90.86 wt%) by XRF, suggesting potential use as a secondary raw material in civil construction. In summary, our work validates magnetic separation as an economically and environmentally sustainable solution for tailings valorization, with an estimated reprocessing cost 2.5 times lower than the establishment of a traditional mining operation, effectively transforming an environmental liability into a high-value mineral resource.

Ce résumé expose les affirmations des auteurs. BNTIC ne l’interprète pas comme une validation indépendante des résultats.