PRODUCTION OF CAUSTIC ALKALI

摘要

PURPOSE:To obtain stable a product having high purity and high concn. with a low electrolytic cell voltage with a titled method using a vertical type bipolar diaphragm method electrolytic cell mounted with a cation exchange membrane by specifying the supply of an electrolyte, withdrawal of the resultant product and the level of the catholyte and anolyte. CONSTITUTION:Electrolysis of alkali chloride is accomplished by exchanging and mounting a cation exchange membrane as a diaphragm to the installed asbestos diaphragm type electrolytic cell. Brine is supplied through, for example, a field nozzle 15 provided in the lower part of an anode chamber or a nozzle 16 provided in the upper part by using an insertion pipe 17. The formed gaseous Cl2 and thin salt water 19 are withdrawn from the corner in the upper part. Water or thin aq. NaOH soln. is supplied through a nozzle 20 into the lower part of the cathode chamber and the formed NaOH and gaseous H2 in a gas-liquid mixed state is taken out of an upper nozzle 21. The level of the catholyte is maintained at the level in the nozzle 21 or the height above said level and the level of the anolyte is maintained at the level of the cathode or below.