ya mean Epsom salt?
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:
CaCO3 + 2 HNO3 → Ca(NO3)2 + CO2 + H2O
It is also an intermediate product of the
Odda Process:
Ca3(PO4)2 + 6 HNO3 + 12 H2O → 2 H3PO4 + 3 Ca(NO3)2 + 12 H2O
It can also be prepared from an aqueous solution of
ammonium nitrate, and
calcium hydroxide:
2 NH4NO3 + Ca(OH)2 → Ca(NO3)2 + 2 NH4OH
Like related
alkaline earth metal nitrates, calcium nitrate decomposes upon heating (starting at 500 °C) to release nitrogen dioxide:
[2]
2 Ca(NO3)2 → 2 CaO + 4
NO2 + O2 ΔH = 369 kJ/mol