Philippe Dagard

Sulfuric acid concentration with an electro-electrodialysis process

Abstract Commercial anion-exchange membranes exhibit a strong proton leakage which makes them unsuitable for use in the recovery of sulphuric acid from sulphate containing solutions resulting from some hydrometallurgy processes. Experiments are reported which compare membrane permeabilities under electro-electrodialysis conditions. With most commercial membranes, the permeability to sulphate ions decreases rapidly when the acid concentration increases in the anolyte. The highest sulphuric acid concentration is obtained with a prototype membrane which will be shortly produced on an industrial scale.