Effect of TBP on Solvent Extraction of Np(V) with M-Octyl(phenyl)-, N-N Diisobutylcarbamoylmethylphosphine Oxide

Abstract

Solvent extraction of Np(V) from mtnc acid solution by n-octyl(phenyl)-N, N-diisobutylcarbamoylmethylphosphine oxide (CMPO) in the presence and absence of tri-n-butyl phosphate (TBP) has been studied using decalin and n-dodecane as diluents. Without the TBP, Np(V) can be extracted using CMPO in decalin with extraction equation:Np0icaJ+N03caJ+2CMPOcoJ=Np02(N0,)2CMPOco>. The maximum N p( V) distribution ratio using 0.65 M CMPO in decalin from 2M nitric acid is 4. The net effect of TBP to CMPO at 2M nitric acid is slight suppression of Np(V) distribution ratio. However, at low CMPO concentration (0.2M::2) after the Np(V) distribution ratio reaches the minimum value, the distribution ratio gradually increases as the TBP concentration increases. No synergistic interaction of CMPO and TBP has been observed.

Sorption equilibrium and kinetics of NpO2+on dispersed particles of Na-montmorillonite

“…CMPO can extract Np(IV), Np(VI), and daughter nuclides from 1 M HNO 3 solution with high distribution ratios, but cannot extract Np(V) sufficiently, which remains in HNO 3 solution [5][6][7]. Hence, by this procedure, we could prepare the pure Np(V) solution [5][6][7]. Detailed description of extraction procedure is shown in [5].…”

“…Hence, by this procedure, we could prepare the pure Np(V) solution [5][6][7]. Detailed description of extraction procedure is shown in [5]. Then, the pH of the Np stock solution was adjusted with NaOH to pH 6.…”

Batch Tests for Optimisation of Solvent Composition and Process Flexibility of the CHALMEX FS-13 Process

“…Increasing the ratio of TBP to FS-13 in the solvent can therefore account for an increase in Am distribution ratio with increasing TBP ratio. Wisnubroto et al, [44] theorised that the activity of uncomplexed CMPO is reduced by hydrogen bonds with TBP through H + or H 2 O. CyMe 4 -BTBP contains N-donor atoms available for such hydrogen bonds. This theory explains the role that not only increased TBP fraction plays on the solubility of CyMe 4 -BTBP, but also that of acid extraction.…”

Extraction of Np(V) by N,N'-dimethyl-N,N'-dihexyl-3-oxapentanediamide

“…For use in actinide speciation studies, Saito and Choppin [5] have proposed an extraction process, which separates the actinides from (III) to (VI). Although there are many published studies of the extraction of Np(IV) and (VI) [6][7][8][9], there is much less information on the reactions involved in Np(V) extraction [10,11], due to its weak complexation with an organic extractante.…”