In the present work, the quaternary systems of liquid–liquid equilibrium data of ethanol + 2-propanol + (NH4)2SO4 + water at T = (308.15, 318.15 and 328.15) K and ethanol + 2-propanol + Na2SO4 + water at T = 308.15 K were experimentally determined. The binodal curves were fitted to three-parameter empirical equations, , and the tie-lines were described by the Setschenow-type equation as well as another two-parameter equation. Meanwhile, affecting factors such as the temperature, mass fraction of ethanol in the alcohol mixture and type of salt to the phase-forming abilities of the investigated systems were also studied. What’s more, we use excluded volume values (EEV) to evaluate the phase separation abilities of investigated systems. All of the models were successfully correlated with the experimental data, and these data can be used for the development and design of extraction processes utilizing such systems.