Chemically based model to predict distribution coefficients in the Cu--LIX 65N and Cu-KELEX 100 systems

A chemically based thermodynamic model to predict the distribution coefficients have been developed for the Cu-LIX 65N and Cu-KELEX 100 systems. The predictive model makes use of the aqueous phase cupric sulfate complex stoichiometric stability constant expressed as its degree of formation, their extraction mechnism, and the equilibrium constant for the extraction reaction. The distribution coefficient of copper can be predicted by the equation K/sub d/ = k1α/sub o/phi2, where phi is the ratio of the equilibrated organic concentration to the equilibrated hydrogen ion concentration in the aqueous phase, k1 is the effective equilibrium constant containing the quotient of the activity coefficients of the reacting species and α0 is the degree of formation of the free cupric ion in the equilibrated aqueous phase. Excellent agreement between the experimental data and the predicted values was obtained. 6 figures, 4 tables