the purpose of this reaserch is to measure the phase equilibrium data of the ternary system (water + phosphoric acid + 1-nonanol) at different temperatures. experimental solubility curves and tie-line points for the system were obtained at t = 298.2, 308.2 and 318.2 k and ambient pressure. the binodal curve data were detected by the cloud point method. the mass fractions of each layer were achi...