This work reports on a study of copper extraction from ammoniacal aqueous solution by emulsion liquid membranes. Several experiments were conducted to assess the effect of the membrane composition on copper recovery. The beta-diketone reagent LIX 54 was selected as the carrier in examining the permeation of solute. The modelling of solute extraction was done by taking into account the mass transfer in the external phase and globule, and the reaction between the solute-carrier complex and the stripping reagent. The batch extraction of copper was carried out under various experimental conditions such as stirring speed, treatment ratio, solute concentration in the feed phase, carrier concentration in membrane, and stripping agent concentration. The agreement between the calculated results and the experimental data was found to be satisfactory. (c) 2007 Elsevier B.V. All rights reserved.