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Title: Relation Between the Uptake by Anion Exchanges and the Value of the Complex Formation Constants of Ethylene-diaminetetraacetic Acid Complexes of Rare Earths; UBER DEN ZUSAMMENHANG ZWISCHEN DER AUFNAHME DURCH ANIONENAUSTAUSCHER UND DER GROSSE DER KOMPLEXBILDUNGSKON-STANTEN VON ATHYLENDIAMINTE-TRAESSIGSAURE-KOMPLEXEN DER SELTEN ERDEN

Technical Report ·
OSTI ID:4839087

The exchange behavior of EDTA complexes of the rare earths on the strongly basic anion exchanger Dowex 1X4 was investigated with the radioisotopes La/sup 140/, Ce/sup 144/, Nd/sup 147/, Pm/sup 147/,Eu/sup 152//sup -15//sup 4/, Tb/sup 160/, ER/sup / 1>s/sup 69/, Tm/sup 170/, and Yb/sup 175/. The distribution coefficients of these complexes between EDTAcharged exchangers and EDTA-solutions and between extensively charged nitrate exchangers and EDTA- containing nitrate solutions were measured. In earlier works it was shown that between the intensity of the uptake of metal-EDTA complexes in a strongly basic anion exchanger and the magnitude of the stability constants of these complexes no direct relationship exists. The rare earth--EDTA complexes appear to be especially suitable for testing this hypothesis. In both the systems investigated it was found that the uptake of the rare earth --EDTA complexes up to europium (possibly up to the uninvestigated gadolinium) increases, then decreases abruptly notwithstanding the increasing values of the stability constants. The measurements refer to the pH range from 4.5 to 5; at higher pH values the separation factor increases for La and Nd. Infrared spectra of the free complex acids H(Rh(enta)) x H/sub 2/0 were obtained for Nd, Sm, Ho, and Er. Possible origins of the exchange behavior of the Ln--EDTA complexes were discussed and traced back to the configuration changes of the chelates. A radiochemical separation of some rare earth metals in the form of their EDTA complexes on adion exchangers was described. (tr-auth)

Research Organization:
Polish Academy of Sciences. Inst. of Nuclear Research, Warsaw
NSA Number:
NSA-15-027600
OSTI ID:
4839087
Report Number(s):
PAN-217/V
Resource Relation:
Other Information: Orig. Receipt Date: 31-DEC-61
Country of Publication:
Country unknown/Code not available
Language:
English