Solubility Isotherms of Gypsum, Hemihydrate, and Anhydrite in the Ternary Systems CaSO4 + MSO4 + H2O (M = Mn, Co, Ni, Cu, Zn) at T = 298.1 K to 373.1 K
The solubilities of anhydrite in the ternary systems CaSO4 + MSO4 + H2O (M = Co, Ni) were determined through isothermal solution saturation at 348.1 K and 363.1 K. At low bivalent metal sulfate concentrations, anhydrite solubility decreases until it eventually reaches a minimum. Anhydrite solubility subsequently increases with the amount of heavy metal sulfate to a maximum. At this point, further increases in the concentration of metal sulfate decreases the solubility of anhydrite until saturation of the added bivalent metal sulfate. A Pitzer thermodynamic model was selected to predict isopiestic data including calcium sulfate solubilities of the ternary systems CaSO4 + MSO4 + H2O (M = Mn, Co, Ni, Cu, Zn) from 298.1 K to 373.1 K. The functional dependencies of the MSO4 (M = Ni, Cu, Zn) ion interaction parameters with temperature were determined, and the third virial parameters were given. The calculated solubilities are in agreement with the available experimental data. Using the Pitzer model and parameters, the solubility isotherms of metastable solid-phase hemihydrate, as well as gypsum and anhydrite, in the CaSO4 + MSO4 + H2O (M = Mn, Co, Ni, Cu, Zn) systems were predicted over a wide range of temperatures and concentrations.
Compounds
#
Formula
Name
1
CaO4S
calcium sulfate
2
CoO4S
cobalt(II) sulfate
3
NiO4S
nickel monosulfate
4
H2O
water
Datasets
The table above is generated from the ThermoML associated json file (link above).
POMD and RXND refer to PureOrMixture and Reaction Datasets. The compound numbers are included in properties, variables, and phases, if specificied;
the numbers refer to the table of compounds on the left.