THE RECOVERY, PURIFICATION, AND CONCENTRATION OF PLUTONIUM BY ANION EXCHANGE IN NITRIC ACID

A detailed experimental study has shown absorption of plutenium(IV) from 7 M HNO/sub 3/ solutions by strongbase (quaternary amine) anion exchange resins to be a very powerful and versatile processing method for plutonium. The simple expedient of operating at 50 to 60 deg C relieves most of the objections of former anion exchange processes for plutonium in that it permits adequate processing rates and efficiency to be obtained with four per cent cross-linked resins. Commercially available strong-base anion exchange resins Dowex-1, X-4 (50 to 100 mesh), among 50 to 100 mesh resins, and Permutit SK (20 to 50 mesh), among 20 to 50 mesh resins, are markedly superior for most process applications. The anion exchange process consists of an absorption or loading step in which plutonium is absorbed out of a feed solution by the resin, washing step in which impurities are removed by washing the plutonium-laden resin with an appropriate wash solution, and an elution step in which plutonium is stripped off the resin in an appropriate aqueous solution The effects of the pertinent variables in each of these steps have been studied in some detail, yielding informatlon which can be readily extrapolated to new processing applications. (auth)