Solvent extraction separation of Pr and Nd from chloride solution containing La using Cyanex 272 and its mixture with other extractants

Separation possibilities of Pr and Nd from chloride solution containing La at initial aqueous phase pH of 4.94 have been investigated by using solvent extraction technique. Cyanex 272 and its mixture with solvating, cationic and anionic extractants like TBP, TOPO, DOS, Cyanex 301, Versatic-10, Alamine 308, and Alamine 336 have been employed as extractant systems for the separation of LREEs. Under comparable conditions, saponified Cyanex 272 showed some better separation capability than unsaponified Cyanex 272 towards Pr and Nd over La. Among the studied extractant mixtures, the combination of saponified Cyanex 272 and TBP led to complete separation of Pr and Nd over La. Based on this assumption, McCabe–Thiele diagram was constructed by using mixture of 1 M saponified Cyanex 272 and 0.5 M TBP for the extraction of Pr and Nd and its batch simulation of three stages counter current extraction studies indicated that the extraction of Pr, Nd and La was 80%, 90% and 2%, respectively. The quantitative stripping of both Pr and Nd metals were achieved from loaded organic phase by contact with 1 M HCl solution. A solvent extraction process was proposed to separate Pr and Nd over La.