| Popis: |
The transplutonium elements and the rare earths, or lanthanides, are so similar chemically that what is true for one group is generally true for the other. The methods and equipment developed with rare earth separations are applied directly to heavy actinide production separations. Two basic approaches are used to separate those elements, namely, elution development and displacement development chromatography. The first application of pressurized ion exchange to lanthanide and actinide separations was initiated in 1967 to examine this technique for the final separation of trivalent actinides in the TRU facility. Elution development was used at TRU because the preliminary partial separation (LiCl anion exchange) yielded a product containing all the transcurium elements along with only a small fraction of the Am, Cm, and rare earths. With displacement development the metal complexes are eluted at essentially a constant concentration, and the different elements are eluted sequentially one after the other. Other applications for the displacement development were included. Some applications for extraction chromatography are discussed. Future developments were briefly discussed. 3 figures. (DP) |
