Quantitative tuning of ionic metal species for ultra-selective metal solvent extraction toward high-purity vanadium products.

The essence behind metal solvent extraction is the interaction between metal species and organic extractants. Aqueous metal species tuning at the molecular level is critical to improve the extraction efficiency and selectivity of the target metal. Herein, we demonstrate a quantitative metal species tuning strategy which is capable of extracting the most critical metals (e.g., V, W, and Mo) in extraction systems constructed by amines. We reveal the superior activities of V 4 and V 10 species among various V and Cr species by calculations and experiments. In addition, the contribution of various V n species was quantitatively evaluated via Ion Species Contribution Evaluation (ISCE). Our tuning strategy is rationally designed by bridging species characteristics and routine aqueous conditions with extraction activities. Consequently, a three-dimensional model of V and Cr solvent extraction is established for the prediction of reaction regions, and the reactivities of nearly 20 kinds of typical metal species are compared and predicted. Our strategy serves for industrial solvent extraction, and may provide inspiration for the traditional hydrometallurgical revolutionary. [Display omitted] • Metal species tuning is significant for improvements of critical metal recovery. • A quantitative tuning strategy of metal species for solvent extraction is designed. • Superior activities of V 4 and V 10 species in extraction is confirmed and evaluated. • Extraction activities of several metal species (V, Cr, W, Mo) by amines is predicted. [ABSTRACT FROM AUTHOR]