Behavior of a synergistic system in the extraction of Pr(III) from chloride medium using di-2-ethylhexyl phosphoric acid and 2-ethylhexylphosphonic mono-2-ethylhexyl ester

ABSTRACT

This paper will investigate the synergistic solvent extraction of extracted Pr from a chloride medium, using a mixture of two acidic extractants, namely 2-ethylhexylphosphonic mono-2-ethylhexyl ester (P507, HA) and di-2-ethylhexyl phosphoric acid (P204, HB) in kerosene. The stoichiometry of the extracted species was characterized by a classical lg–lg plot analysis. The composition of the extracted complexes has been determined as Pr(HA₂)(HB₂)₂. Moreover, the differences of the extraction behavior from sulfuric and chloride medium were discussed in detail. The values of equilibrium constant and thermodynamic parameters such as △G, △H, and △S were also calculated. A cation-exchange mechanism was proposed and further clarified by slope analysis and IR spectra.

KEYWORDS:

• P507
• P204
• Pr
• rare earths
• synergistic extraction

Acknowledgements

We acknowledge the Shandong Higher School Superior Discipline Talent Team Development Program of China.