The effect of acetohydroxamic acid on the distribution of Np(IV) and Np(VI) between 30% TBP and nitric acid

Abstract Distribution ratios of Np(IV) and Np(VI) between 30 vol.% TBP/ n -dodecane and 1 M nitric acid were measured with varying concentrations of acetohydroxamic acid (AHA). Distribution experiments were undertaken by contacting a 1:1 (v/v) of 30% TBP/ n -dodecane with a simulated solution, which contained a variety of elements such as Ce, Nd, Mo, Zr, Fe, Sr, Ni, Pd and Ru. Distribution ratio values of Np(IV) and Np(VI) in a 1.0 M nitric acid concentration were about D Np(IV)  ≅ 1.0 and D Np(VI)  ≅ 6.4, respectively. But, the addition of AHA brought about a remarkable reduction in the Np extraction with the AHA concentration.