Calcium Carbide


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calcium carbide

[′kal·sē·əm ′kär‚bīd]
(inorganic chemistry)
CaC2 An alkaline earth carbide obtained in the pure form as transparent crystals that decompose in water; used to make acetylene gas.

Calcium Carbide

 

CaC2 a compound of calcium and carbon; one of the most important carbides used in technology. Chemically pure calcium carbide is colorless; industrial calcium carbide varies in color from light brown to black. Calcium carbide has a density of 2.2 g/cm3, and a melting point of 2300°C. Calcium carbide interacts with water to form acetylene: CaC2+ 2H2O = C2H2 + Ca(OH)2; the process is carried out in an excess of water for withdrawal of the liberated heat (30.4 kcal/mole, that is, 127.3 kilojoules per mole). Upon heating, calcium carbide interacts with nitrogen to form calcium cyana-mide: CaC2 + N 2 = CaCN2 + C.

Calcium carbide is prepared in electric furnaces at temperatures ranging from 1900° to 1950°C according to the reaction CaO + 3C = CaC2 + CO, in which a large quantity of heat (450.5 kilojoules per mole) is absorbed. Lime and anthracite or coke serve as raw material for the process. Most of the operating carbide furnaces have an opening at the top; CO is burned down to CO2 after its discharge from the furnace. Closed furnaces with CO extraction have also been constructed. Calcium carbide has found wide application in technology, primarily in the manufacture of acetylene and calcium cynamide and in the reduction of alkali metals.

REFERENCES

Kuznetsov, L. A. Proizvodstvo karbida kaVtsiia. Moscow-Leningrad, 1950.
Strizhevskii, I. I., S. G. Guzov, and V. A. koval’skii. Atsetilenovye stantsii, 2nd ed. Moscow, 1959.
References in periodicals archive ?
He claimed that calcium carbide had been used for ages and was not harmful.
The lag period observed regarding ethylene synthesis might be due to decomposition of calcium carbide (after reacting with water) into acetylene and subsequently biotransformation (enzymatically) of acetylene into ethylene gas which caused a gradual buildup of ethylene in soil.
METHODS TO ARTIFICIALLY RIPEN MANGOES About half a closed fist of calcium carbide is wrapped in a newspaper and placed in the bottom of a big container.
Mean squares from analysis of variance of data for growth and yield parameters of three tomato cultivars (Rio Grande, Tenzila and F-1 3560-S) with calcium carbide application in different rates
Similarly, during the reduction reaction (1), calcium carbide CaC2 is formed on the interface with graphite [5].
Petrochemicals & Other Industries: The chemical sector in Dubai started off with a small acetylene and calcium carbide plant at Jebel Ali in 1985.
The government has decided to impose anti dumping import duties on calcium carbide from China and Malaysia.
NORDIC BUSINESS REPORT-5 March 2002-Odda Smelteverk AS plans to terminate calcium carbide production (C)1994-2002 M2 COMMUNICATIONS LTD http://www.
The Sino-Pak Electro Chemical Industries, manufacturer of calcium carbide has defended the fixation of Import Trade Price (ITP) by the Customs valuation department at $410 per tonne, and said that the ITP for the item had been correctly and fairly fixed.
From their tests the calcium carbide industry was born.
For instance, it has designed and delivered electric reduction furnaces that cover more than 50% of the world's electro-metallurgical production capacity for ferroalloys, pig iron, calcium carbide and copper/nickel mattes.