Abstract: A process for reducing the concentration of perchlorate in an aqueous concentrated multi-component salt solution comprising treating the salt solution with an amphoteric ion-exchange resin to provide an adsorbed perchlorate and multi anion-containing resin and a perchlorate depleted solution; and removing the perchlorate depleted solution. The multi-anion are selected from chloride, chlorate, perchlorate, sulphate, and dichromate, present in electrolytic processes for the production of sodium chlorate.

Abstract: A process for reducing the concentration of perchlorate in an aqueous concentrated multi-component salt solution comprising treating the salt solution with an amphoteric ion-exchange resin to provide an adsorbed perchlorate and multi anion-containing resin and a perchlorate depleted solution; and removing the perchlorate depleted solution. The multi-anion are selected from chloride, chlorate, perchlorate, sulphate, and dichromate, present in electrolytic processes for the production of sodium chlorate.

Abstract: A process for making calcium hypochlorite from caustic soda calcium hydroxide and chlorine by feeding to a stirred reactor an aqueous solution of the total required amount of caustic soda and an aqueous suspension of up to 80% by weight of the total required amount of calcium hydroxide, passing chlorine through the mixture until a redox potential of 650 to 800 mV is reached and while continuing chlorination adding the remaining of the calcium hydroxide at such rate with respect to chlorine that redox potential gradually increases to between 850 and 950 mV. This process prevents thickening and caking which are a recognized problem with conventional batch processes.

Abstract: A process for the continuous preparation of a slurry of calcium hypochlorite wherein a solution of sodium hydroxide is fed to one end of an elongated tubular reaction and a calcium hydroxide slurry and chlorine are introduced through a number of injection sites along the length of the reactor. The redox potential of the reaction mixture at any injection site must not be inferior to that at the immediately preceding site and must be in the range 900 to 950 mV at the exit end of the reactor. The process permits easy control of the reaction temperature and of the viscosity of the reaction mixture.