文摘
Binodal data for the 1-butyl-3-methylimidazolium tetrafluoroborate ([C4mim]BF4) + salt (MgCl2/Na2WO4) + H2O systems were experimentally determined at T = (288.15, 298.15, and 308.15) K, respectively. The binodal data were successfully correlated by an empirical equation with four parameters. The liquid–liquid equilibrium data were given and satisfactorily correlated by the Othmer–Tobias and Bancroft equations, as well as a two-parameter equation. Additionally, the Chen-NRTL model, the Pitzer-Debye–Hückel equation, and the Flory–Huggins equation were used to determine and correlate the liquid–liquid equilibrium data for the studied systems, and good agreement was obtained with these thermodynamic models. The influences of the two salts and temperature on the phase equilibrium were investigated. The phase-separation ability of MgCl2 is stronger than that of Na2WO4. As the temperature of the systems decreases, the two-phase region shows an expansion trend.