Calcium hypochlorite(CHC), with the molecular formula of Ca(CIO)2, is one of the main active ingredients of bleaching powder. With the characteristics of sterilizing and oxidizing, it is mainly used in water treatment or as a bleaching agent. Exposing to the air, it is easy to absorb moisture and carbon dioxide to release hypochlorous acid and chlorine gas. Hypochlorous acid then decomposes to generate hydrogen chlorine and nascent oxygen. The oxidizing power of the nascent oxygen is very strong, and it has the ability to destroy the pigment clusters, so that the colored substances are faded to achieve the bleaching effect. In addition, it has disinfection and sterilization capabilities.
| Item | Calcium Hypochlorite 70 |
| Color | White or Light grey |
| Effective chlorine % | ≥70.0 |
| Moisture% | 4-10 |
| Insolubility | ≤3.0 |
| CaCL2 | ≤9.0 |
| Yearly loss of chlorine | ≤8.0 |
| Granularity(14-50 mesh)% | ≥90.0 |
Calcium hypochlorite is one of the commonly used disinfectant for swimming pools, which is suitable for disinfection of various swimming pools. Calcium hypochlorite tablets, calcium hypochlorite granular and powder are several common forms. It can generate hypochlorous acid through hydrolysis, which has the same disinfection and oxidation effect as chlorine. The disinfection effect is good, and it has the ability of continuous disinfection and the function of removing algae and stains. It can be used in water with different water quality conditions and has a good sterilization effect. For soft water areas, each time chlorination is added, it can also bring calcium into water, thereby reducing the corrosion of the pipeline system and the erosion of the pool wall. For hard water areas, additional calcium can also extend the service life of metal pipe fittings and prevent the erosion of the pool wall. Chlorine, sodium hypochlorite and trichloroisocyanuric acid will drastically change the PH of the pool water. Compared with these chemicals, CHC disinfectant is more neutral, the chemicals to adjust the PH are greatly reduced, which also reduces the total dissolved solids.
It acts like a bactericide, it can kill all kinds of harmful organisms in the water, and it can also eliminate all organic substances in the water to make the water more suitable for human drinking.
Cooling towers, cooling pools and reservoirs usually have the problem of being costed with slime, which can be solved by mixing a CHC solution with an appropriate concentration under close supervision. It is used to prevent the growth of algae in the cooling tower, keep piping and cooling equipment in good condition when improving the process.
Proportioning calcium hypochlorite to an appropriate concentration can be used for disinfection of fruits and vegetables before packaging, which helps to control the contamination of fruits and vegetables by bacteria and fungi, improve the preservation of fruits and vegetables, protect edible fungi from pathogens. It can also be used to prevent soft rot in potatoes and sweet potatoes.
Directly soaking the clothes with the diluted calcium hypochlorite solution can not only disinfect, kill viruses, remove peculiar smells, but also clean and bleach.
Various leather products are prone to mold during the rainy season. Scrub with diluted calcium hypochlorite solution, and then store it after cooling dry can effectively prevent the leather from mouldy and hairy.
Stain pen ink or other non-oily dyes on white clothes, spray or soak them directly with calcium hypochlorite solution to remove stains.
Long-term white clothing or supplies have some maculas, soaking them with a diluted calcium hypochlorite solution can make them white as new.
Used for the bleaching of pulp in the paper industry and the bleaching of cotton, hemp and silk fabrics in the textile industry.
In the chemical industry, used for the purification of acetylene, chloroform and the manufacture of other organic chemical raw materials.
Also can be used as wool shrink-proof agent, deodorant, etc.
Calcium hypochlorite disinfectant has a bactericidal effect by breaking the bond between bacteria and algae proteins. It has a strong inhibitory and killing effect on common bacteria, fungi and algae in circulating water. After contact with microorganism, it can quickly inhibit its growth, which leads to the death of biological cells. It can also penetrate the biofilm attached to the wall of the slime and play a biological peeling effect. It has the advantages of high killing efficiency. Good degradability of active ingredients, no residue, safe operation, good compatibility, and strong stability.
Calcium hypochlorite is made by reacting chlorine gas with calcium hydroxide. Because absolutely dry calcium hydroxide doesn’t react with chlorine gas, chlorine can only be adsorbed by calcium hydroxide. For this reason, in the industry, slaked lime containing free moisture below 1% is used for chlorination, and the chlorine used also contains moisture below 0.06%. The free moisture in these raw materials is used to hydrolyze the chlorine to generate acids (HClO, HCl), and the generated acids are neutralized by slaked lime. Subsequently, relying on the moisture precipitated by the calcium hydroxide during the chlorination reaction, the chlorine continues to be hydrolyzed, so that more calcium hydroxide participates in the reaction process, and a series of compounds are formed. Bleaching powder is a complex composed of these compounds.