# Direct Extraction of Uranium Oxides with N,N-Di(2-ethylhexyl)isobutyramide

## TL;DR

This paper studies a new method to extract uranium oxides using a specific organic solvent, which could simplify nuclear fuel reprocessing and reduce waste.

## Contribution

The study verifies the direct extraction of uranium oxides using N,N-di(2-ethylhexyl)isobutyramide and provides insights into reaction stoichiometry and byproduct formation.

## Key findings

- Uranium oxides can be directly extracted into 1.5 M DEHiBA in n-dodecane.
- Water generated during dissolution forms a separate aqueous phase.
- Reaction stoichiometries for uranium oxides are confirmed through concentration analysis.

## Abstract

The direct extraction of uranium from voloxidized nuclear
fuel
into an organic solvent offers several potential advantages over conventional
hydrometallurgical reprocessing, including reducing the reprocessing
plant footprint, providing an initial degree of decontamination from
fission products, and minimizing the amount of secondary waste from
nitric acid. In this work, the direct extraction of uranium oxides
into 1.5 M N,N-di(2-ethylhexyl)isobutyramide (DEHiBA)
in n-dodecane is examined. UV–vis spectra
and distribution ratios of HNO2 in 1.5 M DEHiBA as well
as the equilibrium organic phase H2O concentrations in
HNO3-loaded 1.5 M DEHiBA are also reported. Hypothesized
reaction stoichiometries for the direct extraction of uranium from
UO2, α-U3O8, and ε-UO3 are verified through analysis of organic-phase U, HNO2, and HNO3 concentrations after dissolution. Water
generated by the dissolution results in the formation of a separate
aqueous phase, which will need to be accounted for in future flowsheet
design.