On the solubility of radium and other alkaline earth sulfate and carbonate phases at elevated temperature
Journal article, 2019

Solubility constant data for alkaline earth sulfate and carbonate phases were collated. Thermodynamic data for these phases were determined by assuming that the solubility (log K-s) of each phase is a function of the inverse of absolute temperature with a constant, but non-zero, heat capacity change. The solubility for all phases, both sulfate and carbonate, exhibits a maximum at a particular temperature, with the temperature at which the maximum solubility occurs increasing as the alkaline earth metals become heavier (for both sulfate and carbonate phases). The heat capacity change was found to be a quadratic function of the square root of the ionic radius. The enthalpy of reaction, at 25 degrees C, is related to the temperature at which the maximum solubility occurs. Combination of these behaviours allows the solubility of the alkaline earth sulfate and carbonate phases to be determined across a temperature range of 0 to 300 degrees C. These relationships allow solubility data to be determined for the same temperature range for radium sulfate and carbonate for which very few literature data are available, particularly for radium carbonate.

Radium carbonate

Temperature dependence

Solubility

Alkaline earth metals

Thermodynamic parameters

Radium sulfate

Author

Paul L. Brown

Rio Tinto

Christian Ekberg

Chalmers, Chemistry and Chemical Engineering, Energy and Material

Artem Matyskin

Chalmers, Chemistry and Chemical Engineering, Energy and Material

Geochimica et Cosmochimica Acta

0016-7037 (ISSN) 0046-564X (eISSN)

Vol. 255 88-104

Subject Categories

Inorganic Chemistry

Materials Chemistry

Metallurgy and Metallic Materials

DOI

10.1016/j.gca.2019.04.009

More information

Latest update

7/17/2019