The extraction kinetics of Fe-III by di-(2-ethylhexyl) phosphoric acid (D2EHPA) were investigated using a Y-Y shaped microfluidic device. Finite-volume simulations were used to examine the accuracy of a single-step dimeric reaction mechanism in fitting the experimental data. Results demonstrate the validity of the proposed mechanism and show that Fe-III extraction occurred at a slow rate (second-order forward rate constant of k(1) = (3.0 +/- 0.1) x 10(-6) m(4)/mols) under a mixed reaction-diffusion resistance regime. The present study provides insight for the control of Fe-III extraction rates in hydrometallurgical processes. (C) 2013 The Institution of Chemical Engineers. Published by Elsevier B.V. All rights reserved.