Rare Earth and Yttrium Phosphate Solubilities in Aqueous Solution

Authors

Xuewu Liu, University of South FloridaFollow
Robert H. Byrne, University of South FloridaFollow

Document Type

Article

Publication Date

1997

Digital Object Identifier (DOI)

https://doi.org/10.1016/S0016-7037(97)00037-9

Abstract

Rare earth and yttrium phosphate solubility products range over more than 1 order of magnitude. Minimum solubilities are observed for light rare earths between Ce and Sm. For the elements Ce, Pr, Nd, and Sm solubility products (log K_sp⁰ (M) = log ([M_i³⁺] [PO₄³⁻])) at zero ionic strength and 25°C can be approximated as log K_sp⁰,(M) = −26.3 ± 0.2. Rare earth phosphate solubility products for well-aged, coarse precipitates increase substantially between Sm and Lu, with log K_sp⁰(Lu) estimated as −24.7. The solubility product of Y is similar to that of Ho (log K_sp⁰ (Y) = −25.0) and is much higher than those of all light rare earths. The solubility product of La is substantially larger than that of Cc (log K_sp⁰(La) − log K_sp⁰ (Ce) ≈ 0.5). Solubility products are strongly dependent on the conditions of solid phase formation. Fresh precipitates are much more soluble than slowly formed, well-aged, coarse precipitates. The pattern of rare earth and yttrium phosphate solubility products is generally similar to the fractionation patterns which are developed during phosphate coprecipitation.

Was this content written or created while at USF?

Yes

Citation / Publisher Attribution

Geochimica et Cosmochimica Acta, v. 61, issue 8, p. 1625-1633

Scholar Commons Citation

Liu, Xuewu and Byrne, Robert H., "Rare Earth and Yttrium Phosphate Solubilities in Aqueous Solution" (1997). Marine Science Faculty Publications. 1711.
https://digitalcommons.usf.edu/msc_facpub/1711