Actinide ion uptake from acidic radioactive feeds using an extraction chromatographic resin containing a branched dialkyl amide.

A dialkyl amide with branched alkyl group, viz. N,N-di(2-ethylhexyl)-propionamide (D2EHPrA) was used as the organic extractant in an extraction chromatographic resin prepared for the first time and evaluated for the separation of uranium from acidic feeds. The distribution coefficient measurements, carried out at varying HNO concentrations, indicated an increase in the UO ion sorption with increasing nitric acid concentration. The UO ion sorption kinetics and sorption isotherms with this resin were investigated in details. The column studies indicated that 8.3 mg of uranium could be loaded on a 2.1 cm column bed volume containing 0.35 g resin. Batch distribution data for other actinides such as Np and Pu indicated that the resin can also be used for effective separation of these metal ions from acidic feeds. Though the resin showed effectiveness for Np and Pu, detailed investigations dealing with macro concentrations of metal ions (in gm quantities) were restricted to uranium only due to hazardous nature of plutonium and limited availability of neptunium. The encouraging results reported in this work is an indication of the possible application of this resin for the recovery or pre-concentration of UO, Np and Pu ions from large volumes of aqueous solutions of moderate acidity.