Solubility and stability of liebigite, Ca2UO2(CO3)3·10H2O(cr), in dilute to concentrated NaCl and NaClO4 solutions at T = 22–80 °C

Abstract The solubility and thermodynamic stability of a synthetic liebigite was investigated in NaCl and NaClO4 solutions within a wide range of ionic strength (0.03 m ≤ Im ≤ 5.61 m), pH (7 ≤ pHm ≤ 9, with pHm = –log [H+]) and temperature (22 °C ≤ T ≤ 80 °C) conditions. A comprehensive characterization of the synthetic solid phase using XRD, quantitative chemical analysis, TG–DTA, SEM–EDS, IR and Raman spectroscopy confirmed the stoichiometry of Ca2UO2(CO3)3·10H2O(cr). At room temperature, liebigite remains stable and controls the solubility of U(VI) in the investigated NaCl and NaClO4 systems with Im ≤ 0.51 m. For the same temperature but high ionic strength (5.61 m NaCl), liebigite trans…