Calcium cyanamide

 

Calcium cyanamide

Chemical formula	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

   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

   Ca(OCN)₂

   {

   →

   800 °C}

   CaCN₂ + CO₂

   Ca(OCN)₂ + 3 O₂

   {

   →

   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.

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

CaC₂ + N₂

{CaCl₂

→

700°C}

CaCN₂ + C

Storage

Watertight dry container