Calcium Hypochlorite Overview

Calcium hypochlorite is a chemical compound with the chemical formula of Ca(ClO)2. Calcium hypochlorite is also referred as Calcium Salt, Lime chloride and chloride of lime. Calcium hypochlorite is widely used for a water treatment and bleaching agent. Different grades of calcium hypochlorite are available depends upon its applications in different industries.

Preparation
Calcium hypochlorite is commercially prepared by means of sodium process and calcium process. Calcium hydroxide and sodium hydroxide are the main reactants for the production of commercial calcium hypochlorite production.

2 Ca(OH)2 + 2 Cl2 → Ca(OCl)2 + CaCl2 + 2 H2O
2 Ca(OH)2 + 3 Cl2 + 2 NaOH → Ca(OCl)2 + CaCl2 + 2 H2O + 2 NaCl

Bleaching powder is a mixture obtained from the above reaction with a composition of calcium hypochlorite, calcium chloride, water and untreated slaked lime.


Properties

  • Calcium hypochlorite is a yellowish white stable solid.
  • Calcium hypochlorite is not soluble in water and is more preferably in soft to medium hard water.
  • Calcium hypochlorite is commercially occurring in two forms such as calcium hypochlorite hydrate and calcium hypochlorite unhydrate forms.
  • Calcium hypochlorite is to be kept in a cool, dry place for a safety concern.
  • Calcium hypochlorite is noncombustible, but Calcium hypochlorite will induce the burning of combustible materials.
  • Calcium hypochlorite is a strong oxidizing agent, particularly in the presence of water at higher temperatures.
  • Calcium hypochlorite is decomposed by water with evolution of chlorine gas and heat.
  • Calcium hypochlorite produces toxic gaseous chlorine gas in the presence of concentrated acids.

Water treatment industry
In wastewater treatment, Calcium hypochlorite is used for effluent water treatment from various chemical industries. It is an effective chemical compound for purifying water for commercial purposes and for treatment of wells, reservoirs, filters and chemical equipments. Calcium hypochlorite is used an a sanitizer in outdoor swimming pools in combination with acyanuric acid stabilizer, which reduces the loss of chlorine due to ultraviolet radiation. Calcium hypochlorite is utilized in the sewage water treatment effluent to reduce Biological Oxygen Demand, control odors, and aid in sewage coagulation.

Pharmaceutical industry
Calcium hypochlorite is extensively used in the pharmaceutical industry for the preparation of tablets and capsules. Calcium hypochlorite tablets are available in different forms such as granular, briquette and versatile tablet forms. Calcium hypochlorite is used in the pharmaceutical industry for preventing powdering, control the dosage of each product, enhances dissolving features and stop moisture from being absorbed readily.

Other applications
Calcium hypochlorite is also proven powerful germicide and biocide capable of killing harmful pathogenic like bacteria, algae and fungus. Calcium hypochlorite is used as reacting agent for the manufacture of chloroform and bleaching powders. Calcium hypochlorite is used as a sanitizing food and beverage products for hospital purposes. Calcium hypochlorite is utilized as an important feedstock in the production of chloroform. Calcium hypochlorite is an effective alternative chlorination for water supplies in an emergency situations.
 

PRODUCT IDENTIFICATION
CAS NO. 7778-54-3
EINECS NO. 231-908-7
FORMULA Ca(OCl)2
MOL WT. 142.98
H.S. CODE 2828.10
TOXICITY Oral rat LD50: 850 mg/kg
SYNONYMS
Calcium hypochloride; Hypochlorous Acid, Calcium Salt; Losantin; Hy-Chlor; Chlorinated lime; Lime chloride; Chloride of lime;
PHYSICAL AND CHEMICAL PROPERTIES
PHYSICAL STATE White or grayish-white powder with chlorine-like odor
MELTING POINT 177 C (Decomposes with release of heat and oxygen)
SPECIFIC GRAVITY 2.35
SOLUBILITY IN WATER Soluble with release of chlorine gas
VAPOR DENSITY 6.9
NFPA RATINGS Health: 3; Flammability: 0; Reactivity: 1; Other: Oxidizer
FLASH POINT Not combustible but thermally unstable at higher temperature.
STABILITY Rapidly decomposes on expsure to air, heat or sunlight.
SALES SPECIFICATION
65% GRADE
APPEARANCE White Powder or Granule
CHLORINE CONTENT

65% min

MOISTURE 4.0% max
Fe 0.03% max
Mn 40ppm max
INSOLUBLES IN WATER 25.0% max
70% GRADE
APPEARANCE White Powder or Granule
CHLORINE CONTENT 70% min
MOISTURE 5-10%
Fe 0/03% max
Mn 40ppm max
INSOLUBLES IN WATER 18.0% max
PARTICLE SIZE 90% (10 – 50 mesh)