Bleaching calcium hypochlorite

Potassium chlorate Potassium chloride, Bleach (Calcium hypochlorite) Low explosive, lED filler, Black powder weapon propellant, Oxidizer... 

Ammonia alum Ammonium chloride, hydroxide, and molybdate Ammonium compounds, except for fertilizer Ammonium perchlorate Ammonium thiosulfate Barium compounds Bauxite, refined Beryllium oxide Bleach (calcium hypochlorite), industrial... 

Really, gold is soluble in any solution that contains both a chloride ion and an oxidizing agent. Even common salt (NaCl) or laundry bleach (calcium hypochlorite) will provide a free chloride ion. 

Dichloranrine-T (p-toluenesulphondichloramide). Prepare about 200 ml. of a saturated solution of calcium hjrpochlorite by grinding a fresh sample of bleaching powder with water and filtering with shght suction. Dissolve 5 g. of p-toluenesulphonamide in as small a volume of the calcium hypochlorite solution as possible (about 150 ml.) and filter the solution if necessary. Cool in ice, and add about 50 ml. of a mixture of equal volumes of glacial acetic acid and water slowly and with stirring until precipitation is complete. The dichloramine T separates out first as a fine emulsion, which rapidly forms colourless crystals. Filter the latter... 

Miscellaneous. Both whiting and hydrated lime are used as diluents and carriers of pesticides, such as lime—sulfur sprays, Bordeaux, calcium arsenate, etc. The most widely used bleach and sterilizer, high test calcium hypochlorite, is made by interacting lime and chlorine (see Bleaching AGENTS). Calcium and magnesium salts, such as dicalcium phosphate, magnesium chloride, lithium salts, etc, are made directly from calcific and dolomitic lime and limestone. 

Calcium Hypochlorite. This chemical, marketed since 1928, is one of the most widely used swimming-pool water sanitizers. Calcium hypochlorite, a crystalline sofld, is a convenient source of available chlorine and is sold in granular or tablet form for use in home, semiprivate, and commercial pools. When dissolved in water, Ca(OCl)2 forms hypochlorous acid and hypochlorite ion similar to NaOCl. It contains small amounts of stabilizing Ca(OH)2, which has a very small effect on pool pH (7). Calcium hypochlorite has superior storage stabiUty and much higher available CI2 concentration than Hquid bleach, which reduces storage requirements and purchasing frequency. 

After World War I, other chlohne-based bleaches were developed. In 1921 the use of chlorine dioxide for bleaching fibers was reported followed by the development of the commercial process for large-scale production of sodium chlorite. In 1928 the first dry calcium hypochlorite containing 70% available chlorine was produced in the United States. This material largely replaced bleaching powder as a commercial bleaching agent. 

The largest use of calcium hypochlorite is for water treatment. It is also used for I I and household disinfectants, cleaners, and mildewcides. Most of the household uses have been limited to in-tank toilet bowl cleaners. In areas where chlorine cannot be shipped or is otherwise unavailable, calcium hypochlorite is used to bleach textiles in commercial laundries and textile mills. It is usually first converted to sodium hypochlorite by mixing it with an aqueous solution of sodium carbonate and removing the precipitated calcium carbonate. Or, it can be dissolved in the presence of sufficient sodium tripolyphosphate to prevent the precipitation of calcium salts. However, calcium hypochlorite is not usually used to bleach laundry and textiles because of problems with insoluble inorganic calcium salts and precipitation of soaps and anionic detergents as their calcium salts. 

Bleach Liquor. Bleach Hquor or lime bleach Hquor is an aqueous solution of calcium hypochlorite and calcium chloride. It typically contains 30—35 g/L of available chlorine, though it may be as high as 85 g/L. It has been used in pulp bleaching, when it can be made more cheaply than sodium hypochlorite. It is prepared on site by chlorinating lime solutions. 

Historically, bleaching powder and tropical bleach were significant sources of available chlorine but very Httle are used today. This is because of the greater availabiUty of sodium hypochlorite solutions and the development of calcium hypochlorite. They are stiU used to sanitize fields, drainage ditches, and reservoirs where its insoluble portion is not important. And, they are important sources of available chlorine within some less developed tropical countries. 

A study of the North American bleaching agent market was completed in June 1988 and includes consumption quantities for the year 1986 (156). Chlorine consumption for 1986 was 1.86 x 10 t. The North American consumption volume of other chlorine-containing bleaching compounds including sodium and calcium hypochlorite, chlorinated isocyanurates, and hydantoins was 286,000 t. The 1986 North American consumption of sodium chlorate was estimated at 5.5 x 10 t. 

Dichlorine monoxide is an intermediate in the manufacture of calcium hypochlorite. It has been used in sterilization for space appHcations (70) (see Sterilization techniques). Its use in the preparation of chlorinated solvents (71) and chloroisocyanurates has been described. Chlorine monoxide has been shown to be effective in bleaching of pulp (qv) and textiles (72—74). 

Calcium hypochlorite is the principal commercial soHd hypochlorite it is produced on a large scale and marketed as a 65—70% product containing sodium chloride and water as the main diluents. A product with a significantly higher available chlorine, av CI2, (75—80%) has been introduced by Olin. Calcium hypochlorite is also manufactured to a smaller extent as a hemibasic compound (- 60% av Cl ) and to a lesser extent in the form of bleaching powder (- 35% av CI2). Lithium hypochlorite is produced on a small scale and is sold as a 35% assay product for specialty appHcations. Small amounts of NaOCl ate employed in the manufacture of crystalline chlorinated ttisodium phosphate [56802-99-4]. 

Calcium Hypochlorite (Bleach Liquor). Bleach hquor is a solution of Ca(OCl)2 and CaCl2 containing some dissolvedhme. The av CI2... 

Because of the simplicity of the manufactuting process it is cheaper than neutral calcium hypochlorite, and because of its higher av CI2 and better stabiHty, it is a superior alternative to bleaching powder [64175-94-6J. 

Applications. Because of its high lime content, the use of hemibasic calcium hypochlorite ia geaeral sanitatioa is limited. It is used primarily ia Japan and lesser developed countries as an alternative to bleaching powder. 

Bleaching Powder. This material, known siace 1798, is made by chlorination of slightly moist hydrated lime, calcium hydroxide [1305-62-0] Ca(OH)2- It has the empirical formula Ca(OCl)2 CaCl2 Ca(OH)2 2H20. Its compositioa, loag a subject of coatroversy, was estabHshed by phase studies, microscopy, and x-ray diffraction techniques (241). The initial chlorination products are monobasic calcium chloride [14031-38-4] and dibasic calcium hypochlorite [12394-14-8] ... 

About 93% of the CaCOs mud is dried and lecalcined in rotary kilns to recover the CaO. Calcium hypochlorite bleaching liquor (p. 860) for paper pulp is obtained by reacting lime and CI2. 

Discussion. Most hypochlorites are normally obtained only in solution, but calcium hypochlorite exists in the solid form in commercial bleaching powder which consists essentially of a mixture of calcium hypochlorite Ca(OCl)2 and the basic chloride CaCl2,Ca(0H)2,H20 some free slaked lime is usually present. The active constituent is the hypochlorite, which is responsible for the bleaching action. Upon treating bleaching powder with hydrochloric acid, chlorine is liberated ... 

Sodium hypochlorite is one of the best disinfectants known, capable of killing bacteria, yeasts, fungus, spores, and even viruses. Because it is an excellent disinfectant as well as a bleaching agent, it is used in many household cleaners. Sodium hypochlorite is also used to disinfect water supplies and swimming pools (although calcium hypochlorite in powder or pellet form is often used as a substitute, due to the convenience of its solid form). 

While pure chlorine gas will certainly bleach colors, laundry bleaches use sodium hypochlorite or calcium hypochlorite, which works by releasing oxygen, not chlorine. The chlorine remains in solution, either as sodium chloride (table salt), or calcium chloride. These bleaches are made by bubbling chlorine gas through a solution of sodium hydroxide (lye) or calcium hydroxide (quicklime). 

The calcium hypochlorite or sodium dichloroisocyanurate used to disinfect swimming pools also bleaches hair, although contrary to popular belief it does not turn the hair green. It simply allows the green copper sulfate from the water to show up in the hair. The copper sulfate comes from the reaction of the copper pipes in the plumbing to the sulfuric acid used to neutralize the alkalies in the chlorination chemicals. 

Oxidizing bleaches kill microbes by reacting with cell membranes and cell proteins. The most widely used is sodium hypochlorite for household and hospital uses, and calcium hypochlorite for drinking water and swimming pool disinfecting. 

The oxygen either bubbles out of the solution or attacks oxidizable material. Calcium hypochlorite is the main component of bleach powders and is used for purifying the water in home swimming pools. It is used for swimming pools in preference to sodium hypochlorite because the Ca2+ ions form insoluble calcium carbonate, which is removed by filtration sodium would remain in solution and make the water too salty. 

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