Heterogeneous Equilibria in Systems M~(II)(AsUO_(6))_(2)(centre dot)nH_(2)O-Aqueous Solution (M~(II) velence Mg~(2+), Ca~(2+), Sr~(2+), Ba~(2+))

摘要

A comprehensive study of the state of alkaline-earth metal uranoarsenates in saturated aqueous solutions in a wide range of solution acidity was made. A physicochemical model based on the experimental solubility data and on principles of equilibrium thermodynamics was suggested for quantitative description of the state of the heterogeneous system crystalline uranoarsenate M~(II)(AsUO_(6))_(2)(centre dot)nH_(2)O-aqueous solution. The model was applied to calculation of the solubility products and Gibbs energies of formation of alkaline-earth metal uranoarsenates, and also of distribution diagrams of equilibrium aqueous solutions and bottom phases.