PURPOSE: To keep the environment safe and healthy and to simpilfy the device by treating an aq. soln of sodium chlorite with an H-type cation-exchange resin and a C1-type anion-exchange resin.
CONSTITUTION: A granular H-type cation-exchange resin, a C1-type anion- exchange resin or their mixture is added to an about 4% aq. soln. of sodium chlorite and agitated at ordinary temp. for 20-30 min, and the soln. is separated, passed through the resin bed or electrodialyzed with a membrane-shaped resin to bring about a reaction shown by formula I or II or both reactions. The by-produced chlorate ion and the remaining chlorite ion are brought into contact with the C1-type anion-exchange resin and exchanged with harmless chlorine ion. The spent two kinds of ion-exchange resins are treated with about 2 N hydrochloric acid of about five times the amt. of the resin and reused.
HASEGAWA TAKAO
HASHIMOTO KATSUHIRO
