Extraction method for valuable elements of low-grade vanadia–titania magnetite

The reduction performance and mechanism of low-grade vanadia–titania magnetite (LGVTM) were investigated using stoichiometric Al powder as a reductant. Subsequently, experiments were conducted to study the effect of Al ratio on the composition and microstructure evolution of ferroalloys and recoveries of Fe, V, Ti, and Cr. It was found that the oxides of valuable elements were reduced to metals simultaneously in a thermal explosion at 940 °C, forming a multicomponent ferroalloy. Ti, V, and Cr contents had common regularities in the ferroalloy, which first increased and then decreased, while Fe decreased with an increase in Al ratio. The main oxide inclusion transformed from Fe2SiO4 to Al2O3 in the ferroalloy with an increasing Al ratio. The recovery of Fe increased at first and then basically was constant. The recoveries of V, Ti, and Cr first increased and then decreased with Al ratio. The optimum Al ratios are different for each element, being 1.1, 1.15, 1.0, and 0.9 for Fe, Ti, V, and Cr, respectively. The combination of Al2O3 and TiO and the formation of (Al0.948Cr0.052)2O3 negatively affected the recovery of Ti and Cr, respectively. •A thermal explosion method is employed to investigate the recoveries of valuable elements of LGVTM.•Reduction performance and mechanism of LGVTM were investigated by using Al powder as a reductant.•Calorific value per unit mass raw material increases first and then decreases with increasing Al ratio.•Combination of Al2O3 and TiO and the formation of (Al0.948Cr0.052)2O3 are adverse to the recoveries of Ti and Cr.