A study of the treatment of an acidic mine drainage to extract its Cu(II) content by emulsion liquid membranes is made. Copper was removed using 5-nonylsalicylaldoxime (LIX-860 N-IC) dissolved in aviation kerosene. The effects of various factors, such as pH and metal content in the feed solution, carrier concentration and surfactant content in the membrane, acidity of the stripping solution, and stirring speed to prepare the primary and the double emulsion, are reviewed. The experimental data were analyzed in terms of a metal transport mechanism based on a facilitated transport model, which takes account the chemical reaction between the metal and the oximic extractant and the diffusion processes in the aqueous phase close to the external interface of membrane. The results indicate that with adequate control and adjustment of these experimental conditions the extraction extent of metal through the membrane as well their degree of enrichment in the stripping liquor can be favored. (C) 2008 The Institution of Chemical Engineers. Published by Elsevier B.V. All rights reserved.