An improved process for calcium hypochlorite production.

摘要

A process for producing neutral calcium hypochlorite comprising admixing lime, an alkali metal hypochlorite and dibasic calcium hypochlorite crystals in a mixing zone slurry. The mixing zone slurry is reacted with chlorine to form a paste of neutral calcium hypochlorite. The paste is then separated into a cake of neutral calcium hypochlorite and a paste liquor. A slurry of lime is fed to a crystallizer to react with the paste liquor to form a slurry of dibasic calcium hypochlorite crystals in a mother liquor. Crystals of dibasic calcium hypochlorite are then separated from the dibasic mother liquor and recycled to the mixing zone. In a modification, the invention provides a process including the preliminary steps of reacting an aqueous slurry of lime containing insoluble impurities with chlorine in a first crystallizer to form a first slurry of dibasic calcium hypochlorite crystals and insoluble impurities in a calcium chloride mother liquor. The insoluble impurities are separated from the first slurry of dibasic calcium hypochlorite crystals by employing separation means for classifying solids with respect to particle size. Dibasic calcium hypochlorite crystals are then separated from the calcium chloride mother liquor and admixed with a alkali metal hypochlorite and recycle dibasic calcium hypochlorite crystals in the mixing zone to form the mixing zone slurry.