Continuous manufacture of sodium dithionite solutions by cathodic reduction

摘要

Concentrated dithionite solutions are produced by cathodic reduction of an aqueous solution, containing sulfite and/or bisulfite, which is circulated by pumping. The cathode and anode chambers are separated from one another by a permselective cation exchanger membrane. The catholyte must be circulated at least 10 times per hour and the selective catholyte volume outside the cell, defined as a = Vtotal -VC/Vtotal, SHOULD BE LESS THAN 0.9.