Calcium nitrite
Description
Calcium nitrite (Ca(NO₂)₂) is a white to light yellow, odorless crystalline powder or deliquescent solid, highly soluble in water, serving primarily as a corrosion inhibitor and accelerator in concrete admixtures.
Properties
It has a density of about 2.23–2.26 g/cm³, decomposes around 390°C (anhydrous form), and forms hydrates like Ca(NO₂)₂·4H₂O; as a strong oxidizer, it reacts with reducing agents and is stable under normal storage but incompatible with combustibles.
Production
Typically prepared by absorbing NOx gases (from nitric acid production or ammonia oxidation) into lime milk (Ca(OH)₂ slurry), followed by filtration, evaporation, cooling, and crystallization of the nitrite-rich solution.
Main uses
Widely added to reinforced concrete (1–4% by cement weight) to passivate steel rebar against chloride-induced corrosion, promote early strength at low temperatures (down to -20°C), and act as antifreeze; also used in fertilizers, dyes, and metallurgy.
Specifications
| Model No. | N-CH1520 |
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