|Jmol-3D images||Image 1|
|Molar mass||80.102 g/mol|
|Appearance||White solid (Often gray or black from impurities)|
|Melting point||1340 °C |
|Boiling point||1150-1200 °C (sublim.)|
|Solubility in water||Reacts|
|EU classification||Harmful (Xn)
|R-phrases||R22 R37 R41|
|S-phrases||(S2) S22 S26 S36/37/39|
|Except where noted otherwise, data are given for materials in their standard state (at 25 °C (77 °F), 100 kPa)|
|(what is: / ?)|
Calcium cyanamide or CaCN2 is a calcium compound used as fertilizer, first synthesized in 1898 by Adolph Frank and Nikodem Caro (Frank-Caro process). It is formed when calcium carbide reacts with nitrogen. It is commercially known as Nitrolime.
- CaC2 + N2 → CaCN2 + C
The reaction takes place in large steel chambers. An electric carbon element heats the reactants to red heat. Nitrogen is pressurised at 2 atmospheres.
Calcium cyanamide is prepared from calcium carbide. The carbide powder is heated at about 1,000°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 → CaCN2 + C (ΔHƒ°= –69.0 kcal/mol at 25°C)
- CaCN2 + 3 H2O → 2 NH3 + CaCO3
- CaCN2 + Na2CO3 + 2C → 2 NaCN + CaO + 2CO
Through hydrolysis, calcium cyanamide produces cyanamide.
- CaCN2 + H2O + CO2 → CaCO3 + H2NCN
The conversion is conducted on slurries, consequently most commercial cyanamide is sold as an aqueous solution.
Calcium cyanamide is also used as a wire-fed alloy in steelmaking, in order to introduce nitrogen into the steel.
- Pradyot Patnaik. Handbook of Inorganic Chemicals. McGraw-Hill, 2002, ISBN 0-07-049439-8
- Auchmoody, L.R.; Wendel, G.W. (1973). "Effect of calcium cyanamide on growth and nutrition of plan fed yellow-poplar seedlings". U.S. Department of Agriculture, Forest Service. Retrieved 2008-07-18.
- "History of Degussa: Rich harvest, healthy environment". Retrieved 2008-07-18.
- F. Brezina, J. Mollin, R. Pastorek, Z. Sindelar. Chemicke tabulky anorganickych sloucenin (Chemical tables of inorganic compounds). SNTL, 1986.
- Bernd Mertschenk, Ferdinand Beck, Wolfgang Bauer "Thiourea and Thiourea Derivatives" in Ullmann's Encyclopedia of Industrial Chemistry 2002 by Wiley-VCH Verlag GmbH & Co. KGaA. All rights reserved. doi:10.1002/14356007.a26_803
- NIOSH Pocket Guide to Chemical Hazards 0091
- History of calcium cyanamide
- Bioassay of Calcium Cyanamide for Possible Carcinogenicity (CAS No. 156-62-7)
- Entry at Classical Encyclopedia