Electrolysis of alkali metal chloride solution with subsequent production of alkali metal carbonates and hypochlorites

摘要

A process for the production of chlorine by the electrolysis of aqueous sodium chloride solution in which a gaseous stream containing chlorine and carbon dioxide is passed into a first reaction vessel and thence into a second reaction vessel and aqueous sodium hydroxide solution is charged to the first reaction vessel and aqueous sodium hydroxide solution is separately charged to the second reaction vessel, an aqueous solution containing sodium hypochlorite being removed from the first reaction vessel and an aqueous solution containing an alkali metal carbonate being removed from the second reaction vessel. The process enables saleable alkali metal hypochlorite to be produced which may be substantially free of sodium carbonate, and also aqueous sodium carbonate solution which may be used to precipitate polyvalent metal salts in the purification of the aqueous sodium chloride solution.