Olin Corporation

John P Faust

Walter C Saeman

Noel N Coe

Henry R Cramer

John M Casberg

A coated, rounded, solid calcium hypochlorite granule is described which is comprised of granular calcium hypochlorite encapsulated with a plurality of layers of an inorganic salt other than calcium hypochlorite. The inorganic salt is admixed with sufficient alkaline material to form a coating which has a pH in dilute aqueous solution at ambient temperature of at least about nine or higher. The inorganic salt is selected from a group consisting of the chloride, chlorate, nitrate, bromide, bromate and sulfate of an alkali metal. The alkaline material is selected from the group consisting of calcium hydroxide, strontium hydroxide, barium hydroxide, magnesium hydroxide and mixtures thereof. The inorganic salt coating comprises from about 4 to about 45 percent by weight of the calcium hypochlorite granule. The coated, rounded, solid granule of this invention is highly stable and resists chemical decomposition and dusting during storage.

Granular calcium hypochlorite coated with an inorganic salt

A process is described in which granular calcium hypochlorite particles are encapsulated with a plurality of layers of an inorganic salt other than calcium hypochlorite. In this process granular calcium hypochlorite particles are placed in a moving bed and a portion of the moving bed is lifted to the upper part of a distributing zone and released to fall downwardly through the distributing zone to the moving bed. An aqueous medium of the inorganic salt is sprayed onto the falling particles at a temperature sufficiently high to simultaneously evaporate and remove water from the aqueous medium and to provide a coating of a plurality of layers of inorganic salt in solid form on each calcium hypochlorite particle.

Granular calcium hypochlorite coated with an inorganic salt by spray

Novel compositions comprising calcium hypochlorite and a proportion of a polyacrylic acid compound have been produced. the compositions provide accurately controlled concentrations of available chlorine to bodies of water such as swimming pools by reducing the solubility off the calcium hypochlorite. In addition, when employing dispensers for water soluble chemicals in treating very hard or highly alkaline water, inhibition of scale formation and prevention of scale build-up in the dispenser is achieved when the novel compositions are used.

Method of inhibiting scale formation

Novel compositions comprising calcium hypochlorite and a hydrazide of a monocarboxylic acid containing from about 10 to about 24 carbon atoms have been produced. The compositions provide accurately controlled concentrations of available chlorine to bodies of water such as swimming pools by reducing the solubility of the calcium hypochlorite.

Calcium hypochlorite compositions

Calcium hypochlorite compositions, suitable for bleaching and sanitation uses, are provided which have improved resistence to exothermic decomposition. These novel compositions are granules comprised of a core of calcium hypochlorite encapsulated with a coating comprised of a mixture of calcium hypochlorite dihydrate and a water soluble inorganic salt which is non-reactive with and stable in contact with calcium hypochlorite. Generally the coating comprises from about 5 to about 60 percent by weight of each granule and the proportion of water soluble salt ranges from about 0.1 to about 15 percent by weight of each granule. The granular product also resists dusting and caking and has improved retention of its available chlorine on storage.

Growing community of inventors

Hamden, CT, United States of America

John P Faust