Über die Trennung der seltenen Erden durch basische Fällung. IV

Abstract

Mit 2Figuren im Text.

The Basicity Characteristics of Scandium, Yttrium, and the Rare Earth Elements.

“…Similar measurements upon lanthanum, praseodymium, neodymium, and samarium nitrate solutions containing ammonium and cadmium nitrates (345) indicated an even greater effect than with zinc and a feasible separation of lanthanum from the other cerium earths in boiling 2-3 N ammonium nitrate solution containing cadmium nitrate.…”

“…Most observations on the relative solubilities of the oxides or hydrous precipitates in acidic solutions have been only qualitative, although Brauner (45) early pointed out that the solubilities in aqueous ammonium nitrate solution of Di205, Di203, and La203 were in the ratio of 1 to 10 to 29. More recently Prandtl and coworkers (335,342,343,344,345,346) have measured the solubilities of a number of hydroxides in ammonium salt solutions in the presence and absence of cations forming ammonia complexes. (and basicity increases) in the order yttrium, samarium, neodymium, praseodymium, lanthanum.…”

“…An interesting series of investigations involving control of the hydroxyl-ion concentration in ammoniacal solutions through the use of ammonium salts and salts giving cations which form complex ammines has been carried out by Prandtl and his coworkers (335,336,337,339,340,342,343,344,345,346). These investigations were based upon the thesis that if the solubility of a hydrous hydroxide in the mother liquor were increased, the absolute solubility differences between neighboring materials would be magnified, and the hydroxyl-ion concentration could be so controlled that even in concentrated solutions only the least soluble material would separate (343).…”