Abstract
Measurement of the extraction equilibria of samarium and europium in acetate media with dibutylmonothiophosphoric acid (HR) in toluene diluent was carried out at 303 K. It was found that lanthanide ions (Ln3+) are extracted according to the following equation.
Ln3+aq + 3HRorg ↔ LnR3,org + 3H+aq
The extraction equilibrium constants of the metals were obtained. The separation factor between the two metals was a very low 1.1.
A synergistic extraction of the metals with the mixed extractant of dibutylmonothiophosphoric acid and 1,10-phenanthroline (phen) was also conducted to separate the metals efficiently. In this case, the lanthanide ions were extracted according to the following equation.
Ln3+aq + 3HRorg + phenorg ↔ LnR3·phenorg + 3H+aq
The extraction equilibrium constants were obtained, and from them the separation factor was calculated as 1.3. It was found that the factor is improved by the synergistic effect.
