The separation of an HNO3 + Fe(NO3)(3) mixture using an anion-exchange membrane Neosepta-AFN has been investigated in a two-compartment dialysis cell with stirrers. The experiments have proved that this membrane is a very good separator for this mixture, because nitric acid permeates well through the membrane and ferric nitrate is efficiently rejected. The separation is very efficient at high acid concentrations or low content of the salt in the mixture to be dialyzed. (c) 2011 Elsevier B.V. All rights reserved.