Synergistic Solvent Extraction of Lanthanides (III) with Mixtures of Tetraphenylmethylenediphosphine Dioxide and Picrolonic Acid from HCl Solutions

ABSTRACT

The solvent extraction of lanthanides(III) from hydrochloric acid solutions into the organic phase containing neutral bidentate extractant tetraphenylmethylenediphosphine dioxide (L) and picrolonic acid (HP) has been studied. A considerable synergistic effect was observed in the presence of HP in the organic phase containing neutral bidentate organophosphorus ligand. The extraction equilibrium was investigated and the equilibrium constants were calculated. It was found that the lanthanide(III) ions are extracted from weak acidic solutions as LnP₃L and LnP₃L₂ complexes. The mixture L–HP offers higher extraction efficiency toward Ln(III) than mixtures of L with 1-phenyl-3-methyl-4-benzoyl-pyrazolone-5 or picric acid.

Keywords:

• Lanthanides(III)
• picrolonic acid
• synergistic extraction
• tetraphenylmethylenedi phosphine dioxide

Funding

This work was carried out with financial support from the Ministry of Education and Science of the Russian Federation in the framework of Increase Competitiveness Program of NUST “MISiS” (number K2-2016-070).

Additional information

Funding

This work was carried out with financial support from the Ministry of Education and Science of the Russian Federation in the framework of Increase Competitiveness Program of NUST “MISiS” (number K2-2016-070).