Process for preparing granular calcium hypochlorite in a fluidized bed

Abstract

Granular calcium hypochlorite particles having a core of calcium hypochlorite encapsulated in a plurality of layers of calcium hypochlorite are produced from an aqueous slurry of calcium hypochlorite by spraying a pumpable and sprayable slurry of calcium hypochlorite particles onto suspended particles of solid calcium hypochlorite above a moving bed of said particles in a fluidized bed. The solid particles coated with the slurry are heated to simultaneously evaporate and remove water from the slurry whereby said particles are coated with a layer of solid calcium hypochlorite. A portion of the moving bed of coated particles is removed from the spraying zone and further processed, if desired. In one embodiment, the coated particles with or without sizing are further dried to produce granular particles having the desired moisture content. In another embodiment, the withdrawn portion is conveyed to another spraying zone where the particles are coated with a slurry of calcium hypochlorite having a lower available chlorine content than the particles which form the core material. In another embodiment, the withdrawn portion of calcium hypochlorite particles is conveyed to another spraying zone where the particles are coated with a plurality of layers of an inorganic salt. The resulting coated or layered granular particles of calcium hypochlorite have a high level of integrity and resist degradation and dusting when subjected to rather severe handling conditions. In addition, the novel granular calcium hypochlorite particles of this invention are highly stable when contacted with lighted cigarettes, organic materials and the like.

Dependencies are inferred from the claim text.