Elastic strain energy and the distribution coefficient of radium in solid solutions with calcium salts

Natural radionuclide mobility and its influence on U–Th–Pb dating of secondary minerals from the unsaturated zone at Yucca Mountain, Nevada

“…Both elements should behave similarly during distribution-coefficient-driven coprecipitation with Ca (Gnanapragasam and Lewis, 1995;Curti, 1999). However, the absence of correlation between measured 206 Pb/ 207 Pb ratios and Ba concentrations in calcite from coating HD2089A (subsamples Ba1-Ba7; Table EA1) suggests that Ba and the excess Pb in the UZ calcite probably originate from different sources.…”

Radium geochemistry of ground waters in Paleozoic carbonate aquifers, midcontinent, USA

“…Similarly, Andrews et al (1989) Langmuir and Riese (1985) calculated a value for D Ra-barite of 1.8 at 258C and 0.9 at 1008C. A value of 0.013 for D Ra-calcite was calculated by Gnanapragasam and Lewis (1991). These data indicate that Ra is excluded from calcite relative to Ca, but Ra is neither strongly preferred nor excluded by barite relative to Ba.…”

Co-precipitation of radium in high ionic strength systems: 2. Kinetic and ionic strength effects

“…The similar ionic radii of Ra 2+ and Ba 2+ , their electronegativities and electronic configuration and the identical crystallographic structure of pure RaSO 4 and (1925); (2) Gordon and Rowley (1957); (3) Marques (1934); (4) Goldschmidt (1940) in Gnanapragasam and Lewis, 1995); (5) Data from Hahn (1926), calculated by Gnanapragasam and Lewis (1995); (6) Gnanapragasam and Lewis (1995); (7) Doerner and Hoskins (1925) as representing the thermodynamic value. b Extrapolated in this study based on the temperature dependence expression for K 0 D presented by Gordon and Rowley (1957).…”

“…Instead, Ra 2+ co-precipitates with a phase that can reach saturation (henceforth referred to as the host mineral phase). Minerals considered to be appropriate hosts for Ra or that have been found to contain Ra include rock-forming minerals such as gypsum (CaSO 4 Á2H 2 O), anhydrite (CaSO 4 ), calcite (CaCO 3 ) and aragonite (CaCO 3 ) (Langmuir and Riese, 1985;Chan and Chung, 1987;Gnanapragasam and Lewis, 1995;Yoshida et al, 2009) and minor and trace minerals such as barite (BaSO 4 ) (e.g., Doerner and Hoskins, 1925;Gordon, 1955;Gordon and Rowley, 1957), celestine (SrSO 4 ) (Langmuir and Melchior, 1985), Mn and Fe hydrous oxides (Kronfeld et al, 1991), alunite (KAl 3 (SO 4 ) 2 (OH) 6 ) and jarosite (KFe (III) 3 (OH) 6 (SO 4 ) 2 ) (Dickson and Herczeg, 1992a).…”