Calcium cyanamide

 

Calcium cyanamide

Chemical formula	{{#Chem:CaCN2}}
OTP appearance	white solid
Molar Mass(g/mol)	80.102
Density(g/cc)	2.29
Melting Point(°C)	1340
Solubility in water(g/L)	reacts
NFPA 704	0 0 0

Uses

Other

• Production of sodium cyanide
• Production of ammonia
• Production of cyanamide

Natural occurrence

• Does not occur naturally.

Production

Synthesis

from urea

1. Add calcium oxide to molten urea and maintain heat until it is a (mostly) anhydrous solid calcium cyanate

   {{#Chem: CaO + 2 CO(NH2)2 = Ca(OCN)2 + 2 NH3 + H2O }}

2. Calcine at 800 °C in the absence of oxygen, converting the cyanate to cyanamide

   {{#Chem: Ca(OCN)2 { = 800 °C } CaCN2 + CO2}}

   {{#Chem: Ca(OCN)2 + 3O2{ = 800 °C } 2 CaCO3 + 2 N2 + 2 CO2 // incorrect: oxygen available }}

from air nitrogen

• Calcium carbide powder is heated at about 1,100 °C in an electric furnace into which nitrogen is passed for several hours. The product is cooled to ambient temperatures and any unreacted carbide is leached out cautiously with water.

{{#Chem: CaC2 + N2 { = 1100°C } CaCN2 + C }}

• A similar process, called the "Tunnel Kiln" process uses calcium chloride as a coreactant occurs at a much lower temperature

{{#Chem: CaC2 + N2 { CaCl2 = 700°C } CaCN2 + C }}

Storage

Watertight dry container