State of Uranovanadates of d-Transition Elements in Heterogeneous Aqueous-Salt Systems

The state of uranovanadates AII(VUO6)2·nH2O (AII = Mn, Fe, Co, Ni, Cu, Zn, Cd) in aqueous solutions in a wide range of solution acidity was studied. The solubility of AII(VUO6)2·nH2O and the acid–base intervals of the existence of compounds in aqueous solutions were determined, and the conversion products were identified. From the data obtained, the Gibbs functions of formation of uranovanadates and the solubility curves of the compounds were calculated, and the speciation diagrams of U(VI) and V(V) in aqueous solutions and equilibrium solid phases were constructed.