Process for the electrochemical dissociation of alkali sulfates and ammonium sulfate in free alkali and sulfuric acid with simultaneous anodic oxidation of sulfur dioxide

摘要

Process for the electrochemical dissociation of alkali metal sulphates and ammonium sulphate into relatively highly concentrated solutions of alkali metal hydroxide, ammonia and sulphuric acid by use of an electrodialysis cell, divided into three parts, having an anode, which is depolarised by sulphur dioxide, and a cathode, which is depolarised by oxygen, at temperatures of /= 70 to /= 110 DEG C and current densities of 0.5 to 15 kA/m2 and use of an anion exchanger membrane in front of the anode, the polymeric ion exchanger matrix of which comprises a styrene/divinyl benzene copolymer having highly basic quaternary ammonium groups and a hydronium ion blocker.