No abstract

In this study, solvent extraction experiments of Sm from a chloride solution with PC88A and with partially saponified PC88A were performed. The extraction reaction of Sm with PC88A was identified from the experimental data using a graphical method. A chemical model was then developed to predict the distribution coefficients of Sm for its extraction with the saponified PC88A. In the experimental ranges conducted in this study, the equilibrium constants for the solvent extraction of Sm with PC88A and with the saponified PC88A were estimated through an analysis of the ionic equilibria.

Solvent extraction equilibria of FeCl 3 with TPB from chloride solutions were analyzed by considering chemical equilibria, extraction reaction, mass and charge balance equations. The activity coefficients of solutes in aqueous phase were calculated by Bromley equation while ideal behavior was assumed for species in organic phase. Extraction reaction of FeCl 3 with TBP in the experimental range of this study was determined from the dependence of the distribution coefficient of iron on the concentration of chloride ions. By applying ionic equilibria to the results of solvent extraction experiments, equilbrium constant of the extraction reaction was estimated to be 4:5 Â 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 distribution coefficients of iron agreed well with those measured.

Solvent extraction experiments of Gd from chloride solution with PC88A were conducted at different extraction conditions. Solvent extraction reaction was identified from the experimental results using a graphical method, and the corresponding effective equilibrium constant was determined by analyzing the ionic equlibria in a GdCl 3 solution. In the experimental ranges investigated in this study, i.e., ½GdCl 3 0:3 kmol/m 3 , ½PC88A org 3:0 kmol/m 3 and initial pH 2:3, solvent extraction reaction of Gd with PC88A and the corresponding effective equilibrium constant were obtained as follows Gd 3þ þ 2H 2 A 2,org ¼ GdA 3 HA org þ 3H þ ; K ex,eff ¼ 2:8 Â 10 À1 .