The transport fluxes of Al(III), Fe(III), Ti(IV) and Na(I) ions from red mud through charged heterogeneous and Neosepta CMB and CMX cation exchange membranes has been studied as a function of H+ ion concentration in stripping phase. In this process, the feed solutions is initially red mud aqueous solution or half-diluted solution which contains Al(III), Fe(III), Ti(IV) and Na(I) ions and other side is HCl solutions at different concentrations (0.05, 1.0 M). It was shown that the fluxes and recovery factor value of metal ions were enhanced with increasing concentration in feed phase and H+ ion concentration in stripping phase. © 2003 Elsevier B.V. All rights reserved.