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Observations on the rare earths. I. Ion exchange studies on thorium-rare earth mixtures. II. X-ray diffraction studies on certain rare earths salts

Book ·
OSTI ID:6144422

Separation of Th and Nd ions was studied by passing solutions of thorium nitrate and neodymium chloride and mixtures of these two solutions through beds of Amberlite IR-100H contained in glass tubes. The following eluting agents were investigated: 0.5, 5, and 10% hydrochloric acid solutions; 5 and 10% citric acid solutions; saturated ammonium oxalate solutions; saturated ammonium carbonate solutions; 5% ammonium chloride solution; 5% ammonium acetate solution; and 5% acetylacetone solution. It was found that all except ammonium chloride, ammonium acetate, and acetylacetone solutions elute thorium to some extent and that ammonium oxalate and ammonium carbonate solutions do not elute neodymium. Since materials like citric acid elute both ions, only certain agents could be used. Separation of neodymium from thorium was effected by using 0.5 and 5% hydrochloric acid solutions, in the pH range 2.60-2.88, while thorium was separated from neodymium by using saturated ammonium carbonate solutions, pH 8.56, and saturated ammonium oxalate solutions, pH 5.15, 6.28, and 8.70.For separate elution, it was necessary to change to another eluting agent after one species of ions had been eluted. The elution of the thorium ions was never complete, and it is possible that the thorium is bound in the interior of the resin particle or molecule by a coordinate linkage. Part II. A brief discussion of the crystal structures of the rare earth elements, oxides, and halides is given, and a list compiled of those rare earth elements and compounds whose crystal structures have been determined, together with references. The author also prepared powder patterns for neodymium bromate ennea-hydrate, neodymium sulfate octa-hydrate, and praseodymium, neodymium, and thorium acetylacetonates. Praseodymium and neodymium acetylacetonates are isomorphous. The crystal structure of neodymium acetylacetonate was determined and found to be monoclinic, with four molecules per unit cell.

OSTI ID:
6144422
Country of Publication:
United States
Language:
English