Calcium nitrate

Calcium nitrate, also called Norgessalpeter (Norwegian saltpeter), is the inorganic compound with the formula Ca(NO₃)₂. This colourless salt absorbs moisture from the air and is commonly found as a tetrahydrate. It is mainly used as a component in fertilizers but has other applications. Nitrocalcite is the name for a mineral which is a hydrated calcium nitrate that forms as an efflorescence where manure contacts concrete or limestone in a dry environment as in stables or caverns. A variety of related salts are known including calcium ammonium nitrate decahydrate and calcium potassium nitrate decahydrate.

Production and reactivity

Norgessalpeter was the first synthetic nitrogen fertilizer compound to be manufactured. Production began at Notodden, Norway in 1905 by the Birkeland–Eyde process. Most of the world's calcium nitrate is now made in Porsgrunn.

It is produced by treating limestone with nitric acid, followed by neutralization with ammonia:

It is also an intermediate product of the Odda Process: