The kinetics of Ti(IV)-extraction by Cyanex 302 (H(2)A(2)) were investigated by measuring initial Ti(IV)-transfer flux, using a constant interfacial area stirring cell, operated at 3 Hz. The empirical flux equation, at 293 K, is: F = 10(-4.40) [Ti(IV)] (1 + 233[H+])(-1) [H(2)A(2)]((o))(0.5) (1 + 3.20[SO42-])(-1) (F in kmol/m(2) s and [ ] terms are in kmol/m(3)). The activation energy, E-a is measured to be (36-58) x 10(3) kJ/kmol depending on experimental conditions. The enthalpy change on activation, Delta S-+/-, is always highly negative. Analysis of the flux equation has been done, at various concentration regions of H+ and SO42-, to elucidate the mechanism of extraction. The rate-determining chemical reaction step, irrespective of extraction condition, appears as: TiO2+ + A(-) -> TiOA(+). This step occurs in the bulk aqueous phase via an S(N)2 mechanism. The pseudo first order rate constant for the system is 7.5-55 times smaller than the maximum mass transfer coefficient attainable in a Lewis cell. This indicates that the process is chemically controlled or at least mixed controlled.