13780-06-8 Usage
Description
Calcium nitrite, with the chemical formula Ca(NO2)2, is a white or yellowish crystalline compound known for its hygroscopic properties and ability to act as a corrosion inhibitor. It is commonly used in various industrial applications due to its unique properties and benefits.
Uses
1. Used in Construction Industry:
Calcium nitrite is used as an anti-freeze in concrete during winter months. It promotes the hydration of minerals in cement at negative temperatures and reduces the freezing point of operative temperature to -25°C.
2. Used in Steel Industry:
Calcium nitrite is used as a steel rust inhibitor, cleaning steel and protecting it from rust. It extends the useful life of concrete in buildings and structures by protecting steel material from corrosion.
3. Used in Concrete Industry:
Calcium nitrite acts as a coagulator in concrete, improving its early strength and compressive resistance. It is free of chlorine and alkali, reducing alkali aggregation and protecting steel reenforcing bars from chloride-induced corrosion.
4. Used in Lubricants Industry:
Calcium nitrite is used as a corrosion inhibitor when added to lubricating agents, enhancing their performance and durability.
5. Used in Pharmaceutical, Dyes, and Metallurgy Industries:
Calcium nitrite is used as a mild reducing agent in various applications across these industries.
Physical Properties:
Calcium nitrite occurs as yellow-white crystals and has a density of 2.23 g/cm3. It decomposes at 392°C to form nitrogen oxides and CaO. The compound is slightly soluble in alcohol and loses its water of hydration at various temperatures, becoming unstable and oxidizing to the nitrate in air above 220°C.
Chemical Properties:
Calcium nitrite is prepared from nitric oxide and a mixture consisting of calcium ferrate and calcium nitrate. It forms a tetrahydrate that is isomorphous with the strontium and barium salts. The compound is white or yellowish, deliquescent, and exists as hexagonal crystals. It is used to inhibit corrosion in lubricants and concrete.
Preparation
Industrially, calcium nitrite is manufactured by reacting
“NOX” gas with “lime”:
Ca(OH)2 + NO +NO2?Ca(NO2)2 +H2O
By carefully controlling calciumnitrite conditions, the
selectivity on converted lime, on a molar basis, is over
95% pure. It is soluble in water (98.2 g/100 ml at
20 °C) and the solution must be evaporated at low
temperature to obtain the tetrahydrate. If heated with
NO2 gas, it also form the nitrate:
Ca(NO2)2 + NO2?Ca(NO3)2 + NO
Anhydrous calcium nitrite is unstable and slowly
oxidizes in air to form the nitrate. It is also soluble in
alcohol at 0.97 g/100 ml at 20 °C.
Flammability and Explosibility
Notclassified
Purification Methods
Crystallise it from hot water (1.4mL/g) by adding ethanol and cooling to give the hydrate. It is deliquescent. [Ray & Ogg J Am Chem Soc 79 265 1957.]
Check Digit Verification of cas no
The CAS Registry Mumber 13780-06-8 includes 8 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 5 digits, 1,3,7,8 and 0 respectively; the second part has 2 digits, 0 and 6 respectively.
Calculate Digit Verification of CAS Registry Number 13780-06:
(7*1)+(6*3)+(5*7)+(4*8)+(3*0)+(2*0)+(1*6)=98
98 % 10 = 8
So 13780-06-8 is a valid CAS Registry Number.
InChI:InChI=1/Ca.HNO2/c;2-1-3/h;(H,2,3)/q+2;/p-1
