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ON THE STUDY OF CO-PRECIPITATION OF THORIUM AND RARE EARTHS WITH CALCIUM SULPHATE ON A TRACER SCALE

Journal Article · · Journal of the Indian Chemical Society (India) Absorbed Indian J. Appl. Chem.
OSTI ID:4119604

Coprecipitation of thorium (Th/sup 234/) and rare earths (Ce/sup 144/ Pm/ sup 147/, Eu/sup 152/, Eu/sup 154/, and Y/sup 91/) with calcium sulfate was i nvestigated. Thorium and rare-earth tracers were taken up through mixed crystal formation by an unstable form of calcium sulfate that subsequently changes to stable monoclinic gypsum. The range of mixed crystal formation in all these cases was, however, very narrow. When the concentration of the tracer ion exceeded that range, the uptake obeyed an adsorption isotherm. It was found that the presence of one rare earth, the concentration of which is just beyond the range of mixed crystal formation, causes the uptake of another rare earth (in tracer concentration) to obey the Freundlich adsorption isotherm. Uptake of yttrium and thorium, however, differs in this respect from that of rare earths. These two in finite quantity do not exert any influence on the uptake of tracer rare earths and vice versa. A comparative study of the lambda values for different rare earths indicated that mixed crystal formation in these cases is through double-salt formation. (auth)

Research Organization:
Sara Inst. of Nuclear Physics, Calcutta
NSA Number:
NSA-18-006892
OSTI ID:
4119604
Journal Information:
Journal of the Indian Chemical Society (India) Absorbed Indian J. Appl. Chem., Journal Name: Journal of the Indian Chemical Society (India) Absorbed Indian J. Appl. Chem. Vol. Vol: 40; ISSN JICSA
Country of Publication:
Country unknown/Code not available
Language:
English