The separation of a mixture of sulfuric acid and copper sulfate is experimentally investigated in a two-compartment countercurrent dialyzer at steady state using an anion-exchange membrane. The dialysis process is characterized by the recovery yield of acid, the rejection coefficient of salt, and the permeability coefficient of the membrane. The simultaneous transport of sulfuric acid and copper sulfate is quantified by four phenomenological coefficients, which are dependent on the acid and salt concentrations in the feed. They are determined by a procedure consisting of (i) the numerical integration of the basic differential equations describing the concentration profiles of both components on both sides of the membrane and (ii) the optimizing method.