Calciumhypochlorit

BeschreibungCalcium hypochlorite, is an oxysalt; it is a crystalline solid and an oxidizer that decomposes at 212°F (100°C). Calcium hypochlorite is a dangerous fire risk in contact with organic materials. It is also a common swimming pool chlorinator and decomposes in contact with water, releasing chlorine into the water. If a container of calcium hypochlorite becomes wet in storage, the result can be an exothermic reaction. If combustible materials are present, a fire may occur. The chlorine in the compound will be released by contact with the water and will then accelerate the combustion process. The four-digit UN identification number for dry mixtures with not less than 39% available chlorine (8.8% oxygen) is 1748; hydrated with not less than 5.5% and not more than 10% water, the number is 2880; mixtures that are dry, with not less than 10% but not more than 39% available chlorine, are numbered as 2208. The NFPA 704 designation for calcium hypochlorite is health 3, flammability 0, and reactivity 1. The white section at the bottom of the diamond has the prefix “oxy,” indicating an oxidizer. The primary uses are as a bleaching agent, a swimming pool disinfectant, a fungicide, in potable-water purification, and as a deodorant.

VerwendenBleaching powder is actually a mixture of calcium hypochlorite (Ca(ClO)2) and the basic chloride CaCl2, H2O with some slaked lime, Ca(OH)2. The product is generally called “bleaching powder”. It consists of a mixture of calcium chloride (CaCl2), calcium hypochlorite (Ca(OCl)2), and calcium chloride hypochlorite (CaCl(OCl)). Ca(ClO)2 is used in industrial wastewater treatment, sanitation and cleaning, epidemic prevention and household sanitation facilities, as well as for disinfection and sterilization of swimming pools, drinking water, cleaning vegetables, and sanitizing fishponds. Calcium hypochlorite has been used for bleaching of cotton, hemp, fiber, pulp and starch, disinfection of surfaces, and as a sterilant for water treatment. It has also been proposed as a solid fire extinguisher.

synthetischeCalcium hypochlorite is manufactured by two main processes, the socalled “calcium process” and the “sodium process”. These are essentially the same as described for the Mg(ClO)2 salt method given above except that a sodium hypochlorite salt is used in one case and a calcium chloride salt in the other. The products are nearly the same. Calcium hypochlorite is manufactured by the calcium process: 2Ca(OH)2＋2Cl2→Ca(ClO)2＋CaCl2＋2H2O In another method developed for the manufacture of Ca(ClO)2, chlorine gas is reacted with calcium hydroxide: Ca(OH)2＋ 2Cl2→Ca(ClO)2＋ 2HCl In this method, it is claimed that the excess HCl is neutralized by excess Ca(OH)2 to form CaCl2. The product is said to be more “neutral” chemically and more stable than that produced by other methods.