PRODUCTION OF AQUEOUS SOLUTION OF SODIUM HYPOCHLORITE HAVING LOW COMMON SALT CONTENT

摘要

PROBLEM TO BE SOLVED: To provide a method for producing an aqueous solution of sodium hypochlorite having low common salt content, capable of suppressing perchlorination decomposition reaction of sodium hypochlorite in a production step as much as possible and readily constituting continuous production process. ;SOLUTION: This method for producing an aqueous solution of sodium hypochloricie has a first chlorination step for chlorinating an aqueous solution of caustic soda which is a raw material and a second chlorination step for further chlorinating the first reaction solution obtained in this step. In the first chlorination step, a raw material caustic soda aqueous solution in 40-48 wt.% concentration is introduced into the first reaction solution obtained by the first chlorination step and the resultant first mixed solution is subject to vapor-liquid contact with high-concentration chlorine gas in 40-65 vol.% concentration in the same flow direction and ≥100 flow ratio (L/G) to carry out chlorination reaction and in the second chlorination step, the first mixed solution pulled out from the first chlorination step is subjected to vapor-liquid contact with a low-concentration chlorine gas in 10-20 vol.% concentration in the same flow direction and ≥200 flow ratio (L/G) flow ratio to carry out chlorination reaction.;COPYRIGHT: (C)1999,JPO