Physicochemcial Analysis of the Phase Diagram of the Ternary Liquid System [Y(NO3)(3)(TBP)(3)]-Tetradecane-[UO2(NO)(3))(2)(TBP)(2)]

The phase diagram of the ternary liquid system (TLS) [Y(NO3)(3)(TBP)(3)]-tetradecane-[UO2 center dot (NO3)(2)(TBP)(2)] (TBP is tri-n-butyl phosphate) at 298.15 K is constructed. The TLS is characterized by an area of homogeneous solutions and an area of two-phase liquid systems with one of the phases (I) enriched in [Y(NO3)(3)(TBP)(3)] and [UO2(NO3)(2)(TBP)(2)] and the other phase (II), in tetradecane. The intermolecular interaction parameters and excess Gibbs energies (g(E)) for the binary systems and TLS along the binodal curve were calculated from data on the mutual solubility in the binary system [Y(NO3)(3)(TBP)(3)]-tetradecane and the ternary liquid system, using equations of the NRTL theory. For the binary system [Y(NO3)(3)(TBP)(3)] [UO2(NO3)(2)(TBP)(2)], g(E) < 0, and for the other binary systems, g(E) > 0. An algorithm is given for computer calculation of the binodal curve and nodes for the TLS within the framework of NRTL equations using the intermolecular interaction parameters.