Separation of vanadium from black shale leaching solution at low pH is very meaningful,which can effectively avoid the generation of alkali neutralization slag and the resulting vanadium loss.In this study,coordinatio...Separation of vanadium from black shale leaching solution at low pH is very meaningful,which can effectively avoid the generation of alkali neutralization slag and the resulting vanadium loss.In this study,coordination mechanism of vanadium in acid leaching solution at low pH was investigated with the intervention of chloride ions.Under the conditions of pH 0.8,di-(2-ethylhexyl)phosphoric acid concentration of 20%,phase ratio of 1:2,and extraction time of 8 min,the vanadium extraction could reach 80.00%.The Fourier transform infrared and electrospray ionization results reveal that,despite the fact that the chloride ion in the leachate could significantly promote vanadium extraction,the chloride ion does not enter the organic phase,indicating an intriguing phenomenon.Among Cl^(-)-V,SO_(4)^(2-)-V,and H_(2)O-V,the V-Cl bond is longer and the potential difference between coordinate ions and vanadium is smaller.Therefore,Vo^(2+)gets easily desorbed with chloride ions and enter the organic phase.At the same time,the hydrogen ions of di-(2-ethylhexyl)phosphoric acid also enter the water phase more easily,which reduces the pH required for the extraction reaction.展开更多
基金supported by the National Key R&D Program of China(Grant No.2020YFC1909700)the Project of National Natural Science Foundation of China(Grant Nos.51974207 and 51774215).
文摘Separation of vanadium from black shale leaching solution at low pH is very meaningful,which can effectively avoid the generation of alkali neutralization slag and the resulting vanadium loss.In this study,coordination mechanism of vanadium in acid leaching solution at low pH was investigated with the intervention of chloride ions.Under the conditions of pH 0.8,di-(2-ethylhexyl)phosphoric acid concentration of 20%,phase ratio of 1:2,and extraction time of 8 min,the vanadium extraction could reach 80.00%.The Fourier transform infrared and electrospray ionization results reveal that,despite the fact that the chloride ion in the leachate could significantly promote vanadium extraction,the chloride ion does not enter the organic phase,indicating an intriguing phenomenon.Among Cl^(-)-V,SO_(4)^(2-)-V,and H_(2)O-V,the V-Cl bond is longer and the potential difference between coordinate ions and vanadium is smaller.Therefore,Vo^(2+)gets easily desorbed with chloride ions and enter the organic phase.At the same time,the hydrogen ions of di-(2-ethylhexyl)phosphoric acid also enter the water phase more easily,which reduces the pH required for the extraction reaction.
