Kinetics of cerium(IV) and fluoride extraction from sulfuric solutions using bifunctional ionic liquid extractant (Bif-ILE) [A336][P204]

The extraction kinetics of Ce(IV) and Ce(IV)-F− mixture systems from sulfuric solutions to n-heptane solution containing Bif-ILE [A336][P204] ([trialkylmethylammonium][di-2-ethylhewanxylphosphinate]) with a constant interfacial area cell with laminar flow were studied, just to elucidate the extraction mechanism and the mass transfer models. The data were analyzed in terms of pseudo-first-order constants. The effects of stirring speed, specific interfacial area and temperature on the extraction rate in both systems were discussed, suggesting that the extractions were mixed bulk phases-interfacial control process. Supported by the experimental data, the corresponding rate equations for Ce(IV) extraction system and Ce(IV)-F− mixture extraction system were obtained. The experimental results indicated the rate-controlling step. The kinetics model was deduced from the rate-controlling step and consistent with the rate equation.