Calcium cyanamide
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| Names | |
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IUPAC name
Calcium cyanamide
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| Other names
Cyanamide calcium salt, Lime Nitrogen, UN 1403, Nitrolime
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| Identifiers | |
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3D model (Jmol)
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| ChemSpider | |
| ECHA InfoCard | 100.005.330 |
| EC Number | 205-861-8 |
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PubChem CID
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| RTECS number | GS6000000 |
| UNII | |
| UN number | 1403 |
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| Properties | |
| CaCN2 | |
| Molar mass | 80.102 g/mol |
| Appearance | White solid (Often gray or black from impurities) |
| Odor | odorless |
| Density | 2.29 g/cm3 |
| Melting point | 1,340 °C (2,440 °F; 1,610 K) |
| Boiling point | 1,150 to 1,200 °C (2,100 to 2,190 °F; 1,420 to 1,470 K) (sublimes) |
| Reacts | |
| Hazards | |
| Safety data sheet | ICSC 1639 |
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EU classification (DSD) (outdated)
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Harmful (Xn) Irritant (Xi) |
| R-phrases (outdated) | R22 R37 R41 |
| S-phrases (outdated) | (S2) S22 S26 S36/37/39 |
| NFPA 704 | |
| Flash point | Non-flammable |
| US health exposure limits (NIOSH): | |
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PEL (Permissible)
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none |
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REL (Recommended)
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TWA 0.5 mg/m3 |
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IDLH (Immediate danger)
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N.D. |
| Related compounds | |
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Related compounds
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Cyanamide Calcium carbide |
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Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
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 (what is   ?) |
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| Infobox references | |
Calcium cyanamide is the inorganic compound with the formula CaCN2. This calcium derivative of cyanamide (CN22−) is used as fertilizer, first synthesized in 1898 by Adolph Frank and Nikodem Caro (Frank-Caro process). It is commercially known as nitrolime.
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.
The reaction is conducted in large steel chambers. An electric carbon element heats the reactants to red heat. Nitrogen gas is pressurised at 2 atmospheres.
It crystallizes in hexagonal crystal system with space group R3m and lattice constants a = 3.67, c = 14.85 (.10−1 nm).
The main use of calcium cyanamide is in agriculture as a fertilizer. In contact with water it decomposes and liberates ammonia:
It was used to produce sodium cyanide by fusing with sodium carbonate:
Sodium cyanide is used in cyanide process in gold mining. It can also be used in the preparation of calcium cyanide and melamine.
Through hydrolysis, calcium cyanamide produces cyanamide:
The conversion is conducted on slurries, consequently most commercial cyanamide is sold as an aqueous solution.
Thiourea can be produced by the reaction of hydrogen sulfide with calcium cyanamide in the presence of carbon dioxide.
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