Nomenclature
CAS number: 156-62-7
Calcium carbimide; “cyanamide”; nitrolime.
CCaN
2; mol wt 80.10.
C 14.99%, Ca 50.03%, N 34.97%.
N≡CN=Ca.
Description and references
Prepn: Kastens, McBurney, Ind. Eng. Chem. 43, 1020 (1951); Franck, Heimann, Angew. Chem. 44, 372 (1931); Owen, Trans. Faraday Soc. 57, 670 (1961);
Dedman, Owen, ibid. 678.
Properties
Commercial grades may occur as grayish-black lumps
of powder. While pure calcium cyanamide is nonvolatile and noncombustible,
commercial grades may contain small amounts of calcium carbide which
will produce acetylene in containers and processing vessels. Other
contaminants are carbon, Ca(OH)2, CaO, and CaCO3. Pure calcium cyanamide occurs as glistening, hexagonal crystals
belonging to the rhombohedral system. mp ≈1340°; d420 2.29. Sublimes at 1150-1200°.
Heat of formn from CaC2 + N2: -69.0 kcal/mole
(25°). Heat of fusion 1.29 cal/g. Essentially insol in water, but
undergoes partial hydrolysis to the sol calcium hydrogen cyanamide,
a source of cyanamide ions. No known solvent will bring about soln
without decompn.Caution
Potential symptoms of overexposure
are irritation of eyes, skin, respiratory system; headache, vertigo,
rapid breathing, low blood pressure, nausea, vomiting; skin burns
and sensitization; cough; Antabuse-like effects. See NIOSH Pocket Guide to Chemical Hazards (DHHS/NIOSH
97-140, 1997) p 46.Use
As fertilizer, defoliant, herbicide, pesticide;
manuf and refining of iron; manuf of calcium cyanide, melamine, dicyandiamide.
Therapeutic Category (Veterinary)
Has been used as an anthelmintic.