The rates of extraction of Cu(II)–EDTA (ethylenediaminetetraacetic acid) chelated anions from aqueous solutions across microporous hollow fibers to kerosene solutions of Aliquat 336 (a quaternary amine) were measured. Experiments were performed as a function of aqueous pH, the chelated anion concentration, the organic amine concentration, and temperature. From experiments performed on the temperature dependence of extraction rate, it was shown that the resistance of interfacial chemical reaction was negligible. It was shown that the extraction rate increased with increasing concentrations of both the chelated anions and the amine. However, the aqueous pH had little effect on extraction rate under the ranges studied. The mass transfer mechanism of this extraction process was also discussed.© 2000 Society of Chemical Industry