Abstract
Solvent extraction equilibria of $FeCl_3$ from chloride solutions with TBP were analyzed by considering chemical reaction, mass balance, charge balance and extraction reaction. The activity coefficients of solutes in the aqueous phase were calculated by Bromley equation. Extraction reaction of $FeCl_3$ with TBP in the experimental range of this study was determined from the dependence of the distribution coefficient of $FeCl_3$ on the chloride ion concentration. By applying ionic equilibria to the results of solvent extraction, equilbrium constant of the extraction reaction was estimated to be $3.43{\times}10^2$. The equilibrium concentrations of solutes in both phases after extraction could be calculated with the ionic equilibria developed in this study. The predicted concentrations of Fe in the aqueous phase after extraction agreed well with those experimentally measured.