Extraction of vanadium (IV) ions by metal-modified resin through multiple effects: Ionic substitution and proton exchange

Abstract

Acid leaching (especially with strong acid) was the essential step in extracting vanadium from vanadium containing minerals and solid waste. However, the dissolution of impurities (such as iron ions) was accompanied in the acid leaching process. The efficient and selective recovery of vanadium from acid solutions was of great significance for sustainable resource utilization and environmental protection. Metal ions-modified resins for extraction of V(IV) ions from acidic solution containing Fe(II) ion have not been reported, the Mn(II) ion supported resin (Mn-D751) was obtained in this paper. The separation coefficient (βV/Fe) reached 12.087 with Mn-D751 resin under optimum conditions, increasing by nearly two times (βV/Fe = 4.292) compared with the pure D751 resin. The FT-IR spectra manifested that the Mn(II) loading occurred at N and O sites on the resin, while V(IV) adsorption mainly occurred at O sites. The XPS text implied that the bond formed by Mn(II) and O atom during the loading process may be broken after the adsorption of V(IV). The “metals exchange” effect occurred between the Mn(II) and VO2+. Meanwhile, the decrease on pH value of the tailing liquor after V(IV) adsorption indicated that the adsorption was also accompanied by proton exchange. This work had denoted the possibility of V(IV) extraction from Fe(II) containing solution by Mn-D751 resin, providing a new idea of “metal exchange” for V(IV) extraction. Finally, the red mud leaching solution was used as the actual solution, in which the V(IV)/Fe(II) ion separation coefficient was 9.7 and the V(IV) adsorption efficiency was >83 % to achieve the intention of V(IV)/Fe(II) separation.