| Abstract: | Equilibrium studies were made at 25°C in the extraction of zirconium(IV) from sulfuric acid solutions with di(2-ethylhexyl)phosphoric acid (D2EHPA, HR) dissolved in kerosene. The reaction stoichiometry was numerically determined and the compositions of the extracted species were found to be ZrR4 and ZrR4(HR) at low loading ratios of D2EHPA (α < 0.09), but became ZrR4 and ZrR4(HR)3 at relatively higher loading ratios (0.10 < α < 0.32). The equilibrium constants for the formation of these species were also obtained. Furthermore, numerical treatment of the experimental data excluded the existence of polynuclear complexes under the conditions studied (α < 0.32). |
