Evaluation of effective parameters on the non-aqueous solvent extraction of samarium and gadolinium to n-dodecane/D2EHPA

In this study, the non-aqueous solvent extraction is used for the extraction of samarium and gadolinium ions. The aqueous phase comprises ethylene glycol (+1 M LiCl) and metal ions. The various extractants such as D2EHPA, Cyanex272, TOPO, Alamine336 was employed in n-dodecane as a less polar organic phase. The effect of various parameters was investigated on extraction, such as solvent type, extractant type and amount of phase ratio, pH, and temperature. The results showed that D2EHPA extractant diluted in n-dodecane with a concentration of 0.05 M could reach the desirability of extraction efficiency (higher than 89.5%). The optimal concentrations of nitric acid in the stripping stage for gadolinium, and samarium ions were obtained equal to 2 M and 1 M, respectively. The results showed that other rare earth elements (Y(III), and Dy(III)) could be extracted in this system with the non-aqueous system. Therefore, these systems in the leaching process for the extraction of the mixture of rare earth elements and their separation is recommended.