Kinetics of Co(II) Extraction in Co(II) -SO₄^2-( H⁺, Na⁺)-[C₈H₁₇NH₃][Cyanex 272]-sulfonated Kerosene System Using the Single Drop Falling Technique

Abstract

In this research, the kinetics of Co(II) extraction from sulfate medium by the system of “[C₈H₁₇NH₃][Cyanex 272]+diluent sulfonated kerosene” were investigated using the single drop falling technique. The time of drop formation and coalescence was determined for calculating the Co(II) transfer flux. The influences of aqueous pH, Co(II) concentration and [C₈H₁₇NH₃][Cyanex 272] concentration on the revised Co(II)-transfer flux (F') were investigated with aim of obtaining reaction orders for extraction rate equations. With the conditions of Co(II) concentration of 0.24 mol/L, [C₈H₁₇NH₃][Cyanex 272] concentration of 0.24 mol/L, extraction temperature of 298 ± 0.5 K and the normal atmospheric pressure, activation energies (E_a) of extraction reaction for the aqueous pH of 3.0, 4.0 and 5.0 are 3.45, 3.83 and 5.17 kJ/mol, respectively. The equations of extraction rate were calculated and listed in our research based on the different aqueous pH of 3.0, 4.0 and 5.0. The extraction reaction is a diffusion control process according to the values of E_a. The details studies on the kinetics of Co(II) extraction from simulated aqueous solution are significant to optimize its extraction processes.