Separation of neptunium (IV) from actinides by solid phase extraction using a resin containing Aliquat 336.

An extraction chromatographic resin material containing Aliquat 336 as the liquid anion exchanger extractant and Chromosorb W as the solid support was prepared and tested for the uptake of UO2 2+ , Np4+ , Pu4+ , and Pu3+ from nitric acid feed solutions. The resin beads were characterized by thermogravimetry/differential thermogravimetry (TG/DTG) and scanning electron microscopy (SEM) surface morphology analysis. The uptake trend for the metal ions from 3 M HNO3 was found to be Pu4+ > Np4+ > UO2 2+ > Pu3+ which clearly followed the trend of their ionic potentials. In view of the significant difference in the uptake of Np4+ with respect to those of UO2 2+ and Pu3+ , a separation scheme was developed for the selective separation of Np from feeds containing U, Np and Pu in nitric acid. The purity of the product was verified by alpha spectrometry.