Reduction of Neptunium(VI) by Butyraldehyde Isomers in Nitric Acid Solution

The kinetics of the reaction between Np(VI) and butyraldehyde isomers in nitric acid solution was studied to find flow-sheet conditions of the Np separation process from U and Pu. Iso-butyraldehyde was found to have a higher reduction rate than n-butyraldehyde. The former reduction rate at T = 283 to 323 K is described by the following equation:

-d[Np(VI)]/dt
= 6.0 × 10⁶exp(-4.1 × 10³/T)
× [Np(VI)][iso-C₃H₇CHO]₀[H⁺] (M/min).

The latter reduction rate is described by the following equation:

-d[Np(VI)]/dt
= 4.2 × 10⁴exp(-3.4 × 10³/T)
× [Np(VI)][n-C₃H₇CHO]₀[H⁺] (M/min).