Ali Ghanadzadeh Gilani - Department of Chemistry, University of Guilan, Rasht, Iran
Hosein Ghanadzadeh Gilani - Department of Chemical Engineering, University of Guilan, Rasht, Iran
Sina Shekarsaraee - Department of Chemistry, University of Guilan, Rasht, Iran

Experimental tie-line results and phase diagrams were obtained for the ternary systems of {water + phosphoric acid + hydrocarbonic solvent (n-hexane, methylcyclohexane and toluene)} at T = 298.2 K and atmospheric pressure. The hydrocarbonic solvents were one linear aliphatic hydrocarbon (i.e., n-hexane), a cycloaliphatic hydrocarbon (methylcyclohexane), and an aromatic hydrocarbon (toluene). The experimental tie-lines values were also compared with those calculated by the NRTL model. The consistency of the values of the experimental tie-lines was determined through the Othmer–Tobias and Hands plots. Distribution coefficients and separation factors were evaluated over the immiscibility regions and a comparison of the extracting capabilities of the solvents was made with respect to distribution coefficients and separation factors.

Keywords: Liquid–liquid equilibrium, Ternary mixture, Phosphoric acid, NRTL model