Extraction of Some Actinide Ions from Nitric Acid Feeds Using N, N-di-n-hexyloctanamide (DHOA) in an Ionic Liquid


Liquid–liquid extraction studies of \({\text{UO}}_{2}^{{2 + }} \), \( {\text{NpO}}_{2}^{{2 + }} \), Pu(IV), Np(IV), and Pu(III) were carried out from nitric acidic feeds using N,N-di-n-hexyloctanamide (DHOA) in 1-butyl-3-methylimidazolium bis(trifluoromethane sulfonyl)imide (C4mim·NTf2). The distribution studies indicated strikingly different trends in the extraction of tetra- and hexa-valent actinide ions with varying nitric acid concentration. While the distribution ratio values for \({\text{UO}}_{2}^{{2 + }} \) and \( {\text{NpO}}_{2}^{{2 + }} \) were found to decrease with increasing HNO3 concentration up to 1 mol·L−1 HNO3 and did not change thereafter, those obtained for Pu4+ and Np4+ showed monotonic increases over the entire range of acidity. On the other hand, Pu3+ was poorly extracted in the lower acidity range up to 4 mol·L−1, beyond which a sharp increase in the extraction was seen. The nature of the extracted species was obtained using several studies where the ligand and nitrate ion concentrations were varied while keeping the others constant using slope analysis.

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The authors thank Dr. P.K. Pujari, Head, Radiochemistry Division and Director, Radiochemistry & Isotope Group for his support and constant encouragement.

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Correspondence to P. K. Mohapatra.

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Mahanty, B., Verma, P.K. & Mohapatra, P.K. Extraction of Some Actinide Ions from Nitric Acid Feeds Using N, N-di-n-hexyloctanamide (DHOA) in an Ionic Liquid. J Solution Chem 49, 763–776 (2020). https://doi.org/10.1007/s10953-020-00970-8

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  • Actinides
  • DHOA
  • Ionic liquid
  • Extraction
  • Separation