Comparative evaluation of extraction of tetra- and hexa-valent neptunium ions by CMPO in a room temperature ionic liquid

ABSTRACT

Solvent extraction studies were performed to understand the extraction behavior of Np⁴⁺ and NpO₂²⁺ from acidic feeds with CMPO (octyl (phenyl)-N,N-diisobutyl carbamoyl methyl phosphine oxide) dissolved in 1-butyl-3-methylimidazolium bis(trifluoromethane sulfonyl)imide, a water immiscible ionic liquid. Slope analyses on the distribution data revealed the extraction of ML₂ type species, where M = Np⁴⁺ or NpO₂²⁺, and L = CMPO. Studies were also carried out with Pu⁴⁺ and UO₂²⁺ under identical conditions. The nature of the extracted species was found to vary with the nature of the ionic species.

KEYWORDS:

• Neptunium
• Plutonium
• Uranium
• CMPO
• Ionic Liquid

Acknowledgements

The authors thank Dr. Pradeep Kumar Pujari, Assoc. Director, Radiochemistry & Isotope Group for his constant encouragement and keen interest in this work.