Yttrium solubility constants

There have been very few studies on the hydrolytic reactions of actinium(III). There is only one study on the solubility of Ac(OH)3(s) (Ziv and Shestakova, 1965). These authors studied the solubility in a medium of 0.001 moll NH4NO3 and at 22 "C. They corrected for the activities of the ions in the solution and obtained a solubility constant of log A jio = 21.10 0.05. This value appears consistent with the solubility constants obtained for scandium(lll), yttrium(III) and lanthanum(III), with actinium(III) hydroxide as expected being the most basic. The solubility constant obtained by Ziv and Shestakova is retained in the present study for zero ionic strength and 25 C, namely,... 

Borchardt (1964) studied the oxidation of Y metal between 900-1400°C with the following results. The immediate rapid reaction is an appreciable solubility of oxygen in the metal to the extent of 5.1 and 28% for 900 and 1400 C. Diffusion coefficients of oxygen in yttrium metal are approximately 1.3 x 10 (900°C) and 2x 10" (1400 C) cm sec". This phase is followed by a parabolic oxidation with rate constants k = 1.43 x lO exp(-445(X)/J T)g cm sec". The Y metal was observed to have unusual stability due to a protective oxide scale up to a thickness of 100/im. This high temperature oxidation resistance exceeds that of any other elemental base metal. Brett and Seigle (1966) studied the oxidation of liquid rare earth metals. They observed diffusivities of about 10 cmVsec at 1600°C. It must be appreciated that experiments on rare earth metal oxidation... 

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