VERFAHREN ZUR STUFENWEISEN MEMBRAN-ELEKTROLYSE VON ALKALISULFATHAELTIGEN, WAESSERIGEN LOESUNGEN SOWIE VORRICHTUNG ZUR DURCHFUEHRUNG DES VERFAHRENS

For the step-wise membrane electrolysis of alkali-sulphate- containing solutions, said solutions are passed through a multiplicity of 3-chamber electrolysis cells which operate in series and which each have an anode chamber, a central chamber and a cathode chamber which are separated from one another by ion exchanger membranes, and the alkali-sulphate-containing solutions are introduced at least partially into the central chamber of the first electrolysis cell. The electrolyte solutions are dialysed solely by cation exchange membranes in a first group of the electrolysis cells forming the series, the electrolyte solution is removed from the central chamber of the last cell in the series and fed back to the anode chamber of the first cell. This process achieved current yields of at least 80%.