| Calcium carbide | |
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| IUPAC name | Calcium Carbide |
| Identifiers | |
| CAS number | [75-20-7] |
| Properties | |
| Molecular formula | CaC2 |
| Molar mass | 64. IUPAC Nomenclature is a system of naming Chemical compounds and of describing the science of Chemistry in general CAS registry numbers are unique numerical identifiers for Chemical compounds Polymers biological sequences mixtures and Alloys They are also referred to A chemical formula is a way of expressing information about the Atoms that constitute a particular Chemical compound, and how the relationship between those atoms changes Molar mass, symbol M, is the Mass of one mole of a substance ( Chemical element or Chemical compound) 1 g/mol |
| Appearance | Gray-black crystals |
| Density | 2. The density of a material is defined as its Mass per unit Volume: \rho = \frac{m}{V} Different materials usually have different 22 g/cm³, solid (industrial grade) |
| Melting point |
2300 °C |
| Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 100 kPa) Infobox disclaimer and references |
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Calcium carbide is a chemical compound with the chemical formula of CaC2. The melting point of a solid is the temperature range at which it changes state from solid to Liquid. In Chemistry, the standard state of a material is its state at 1 bar (100 Kilopascals exactly A chemical compound is a substance consisting of two or more different elements chemically bonded together in a fixed proportion by Mass. A chemical formula is a way of expressing information about the Atoms that constitute a particular Chemical compound, and how the relationship between those atoms changes Calcium (ˈkælsiəm is the Chemical element with the symbol Ca and Atomic number 20 For the Software development tool targeting the Symbian OS, see Carbide The material is colorless, but most samples appear black through to grayish white lumps, depending on the grade. Its main use industrially is in the production of acetylene. Acetylene ( IUPAC name ethyne), C2H2 is a Hydrocarbon belonging to the group of Alkynes It is the simplest of all alkynes
Contents |
Production
Calcium carbide is produced industrially in an electric arc furnace loaded with a mixture of lime and coke at approximately 2000 °C. An electric arc furnace (EAF is a Furnace that heats charged material by means of an Electric arc. Lime is a general term for various naturally occurring Minerals and materials derived from them in which Carbonates Oxides and Hydroxides of Coke is a solid Carbonaceous material derived from Destructive distillation of low-ash low-sulfur Bituminous coal. This method has not changed since its invention in 1888:
- CaO + 3C → CaC2 + CO
The high temperature required for this reaction is not practically achievable by traditional combustion, so the reaction is performed in an electric arc furnace with graphite electrodes. The Mineral graphite, as with Diamond and Fullerene, is one of the Allotropes of carbon. The carbide product produced generally contains around 80% calcium carbide by weight. The carbide is crushed to produce small lumps that can range a few mm up to 50mm. The impurities are concentrated in the finer fractions. The CaC2 content of the product is assayed by measuring the amount of acetylene produced on hydrolysis. As an example the British and German standards for the content of the coarser fractions are 295 L/kg and 300 L/kg respectively. Impurities present in the carbide include phosphide, which produces phosphine when hydrolysed. Phosphine is the common name for phosphorus hydride (PH3 also known by the IUPAC name phosphane and occasionally phosphamine. [1]
This reaction was an important part of the industrial revolution in chemistry. The Industrial Revolution was a period in the late 18th and early 19th centuries when major changes in agriculture manufacturing and transportation had a profound effect on the In the USA this occurred as a product of massive amounts of cheap hydro-electric power liberated from Niagara Falls before the turn of the 20th century. Hydroelectricity is electricity generated by Hydropower, ie the production of power through use of the gravitational force of falling water The Niagara Falls are massive Waterfalls on the Niagara River, straddling the international border separating the Canadian province of Ontario The twentieth century of the Common Era began on
The method for the production in an electric arc furnace was discovered independently by T. An electric arc furnace (EAF is a Furnace that heats charged material by means of an Electric arc. L Willson and H. Moissan in 1888 and 1892. Ferdinand Frederick Henri Moissan ( September 28, 1852 &ndash February 20, 1907) was a French Chemist who won the [2][3]
Crystal structure
Pure calcium carbide is a colourless solid. The common crystalline form at room temperature is a distorted rock salt structure with the C22− units lying parallel. [4]
Applications
Production of acetylene
The reaction of calcium carbide with water was discovered by Friedrich Wohler in 1862. Friedrich Wöhler (31 July 1800 - 23 September 1882 was a German Chemist, best-known for his synthesis of Urea, but also the first to isolate several
- CaC2 + 2H2O → C2H2 + Ca(OH)2
This reaction is the basis of the industrial manufacture of acetylene, and is the major industrial use of calcium carbide. Acetylene ( IUPAC name ethyne), C2H2 is a Hydrocarbon belonging to the group of Alkynes It is the simplest of all alkynes In China, acetylene derived from calcium carbide remains a feedstock for the chemical industry, in particular for the production of polyvinyl chloride, PVC. The chemical industry comprises the companies that produce industrial chemicals Locally produced acetylene is more economic than using imported oil. [5] Production of calcium carbide in China has been increasing. In 2005 output was 8. 94 million tons with capacity to produce 17 million tons. [6] In the USA, Europe and Japan consumption is generally declining. [7] Production levels in the USA in 1990 were 236,000 tons pa. [4]
Production of calcium cyanamide
Calcium carbide reacts with nitrogen at high temperature to form calcium cyanamide:
- CaC2 + N2 → CaCN2 + C
Calcium cyanamide is used as fertilizer. It is hydrolysed to cyanamide, H2NCN. Cyanamide ( C[[Nitrogen N]]2 H 2 is an Amide of Cyanogen, a white crystalline compound [4]
Steelmaking
Calcium carbide is used:
- in the desulfurisation of iron (pig iron, cast iron and steel)[1]
- as a fuel in steelmaking to extend the scrap ratio to liquid iron depending on economics. Desulfurisation is a chemical reaction involving the removal of Sulfur from a molecule ( e
- as a powerful deoxidizer at ladle treatment facilities. A deoxidizer is a chemical used in a reaction or process to remove Oxygen. In Foundry work a ladle is a container used to transport and pour out molten metals
Carbide lamps
Calcium carbide was used in carbide lamps, in which water drips on carbide and the formed acetylene is ignited. Carbide lamps, also known as acetylene gas lamps, are simple lamps that produce and burn Acetylene (C2H2 which is created by the reaction Carbide lamps, also known as acetylene gas lamps, are simple lamps that produce and burn Acetylene (C2H2 which is created by the reaction These lamps were unusable in coal mines where the presence of the explosive gas methane made them a serious hazard. The presence of explosive gases in coal mines led to the miner safety lamp. A safety lamp is any of several types of lamp, which are designed to be safe to use in Coal mines These lamps are designed to operate in air that may contain However carbide lamps were used extensively in slate, copper and tin mines, but most have now been replaced by electric lamps. Carbide lamps are still used by some cavers exploring caves and other underground areas,[8] though they are increasingly being replaced in this use by LED lights. Caving or spelunking is the recreational Sport of exploring Caves In contrast Speleology is the scientific study of caves and the cave Caving or spelunking is the recreational Sport of exploring Caves In contrast Speleology is the scientific study of caves and the cave They were also used extensively as head lights in early automobiles, although in this application they are also obsolete, having been replaced entirely by electric lamps.
Other uses
In the ripening of fruit, it is used as source of acetylene gas, which is a ripening agent (similar to ethylene). [9]
It is still used in the Netherlands and Belgium for a traditional custom called Carbidschieten (Shooting Carbide). The Netherlands ( Dutch:, ˈnedərlɑnt is the European part of the Kingdom of the Netherlands, which consists of the Netherlands the Netherlands The Kingdom of Belgium is a Country in northwest Europe. It is a founding member of the European Union and hosts its headquarters as well as those To create an explosion, carbide and water are put in a milk churn with a lid. Ignition is usually done with a torch. Some villages in the Netherlands fire multiple milk churns in a row as a New Year's Eve tradition. The old tradition comes from the old pagan religion to chase off spirits. Paganism (from Latin paganus, meaning "country dweller rustic" is a word used to refer to various religions and religious beliefs from across the world
It is used in toy cannons (see Big-Bang Cannon), as well as in bamboo cannons. The Big-Bang Cannon is a unique early 20th century American toy that is still manufactured to this day Meriam buluh or bamboo cannon is a type of home-made Firecracker which is popular during the Hari Raya festive season in Malaysia.
Together with calcium phosphide, calcium carbide is used in floating, self-igniting naval signal flares (see Holmes' Marine Life Protection Association). Calcium phosphide ( CP, Ca3P2 is a chemical that has uses in Incendiary bombs It has the appearance of red-brown crystalline powder or grey lumps A flare, also sometimes called a fusee, is a type of Pyrotechnic that produces a brilliant light or intense heat without an Explosion. The Holmes' Marine Life Protection Association was a United Kingdom company set up in the 19th century to produce marine signal lights and Foghorns It was
Calcium carbide is also used in small carbide lamps called carbide candles, which are used for blackening rifle sights to reduce glare. These "candles" are used due to the sooty flame produced by acetylene.
External links
References
- ^ a b Calcium Carbide, Bernhard Langhammer, Ullmann's Encyclopedia of Industrial Chemistry, Wiley Interscience. (Subscription required)
- ^ J. T. Morehead, G. de Chalmot (1896). "The Manufacture of Calcium carbide". Journal of The American Chemical Society 18 (4): 311 - 331. doi:. A digital object identifier ( DOI) is a permanent identifier given to an Electronic document.
- ^ H. Moissan (1892). "Chimie Mindérale.- Description d'un nouveau four électrique". Comptes rendus hebdomadaires des séances de l'Académie des sciences 115: 1031.
- ^ a b c Greenwood, N. N. ; Earnshaw, A. (1997). Chemistry of the Elements, 2nd Edition, Oxford:Butterworth-Heinemann. ISBN 0-7506-3365-4.
- ^ Ya Dun (23 January 2006). Troubles in the PVC industry. Hong Kong Trade Development Council.
- ^ "Govt takes measures to curb development of calcium carbide sector", BusyTrade. com, 16 May 2007.
- ^ Jamie Lacson, Stefan Schlag and Goro Toki (December 2004). Calcium Carbide. SRI Consulting.
- ^ Caving equipment and culture (from Te Ara Encyclopedia of New Zealand)
- ^ F. Te Ara - the Encyclopedia of New Zealand is an Online encyclopedia created by the Ministry for Culture and Heritage of the New Zealand Government. B. Abeles and H. E. Gahagan, III (1968). "Abscission: The Role of Ethylene, Ethylene Analogues, Carbon Dioxide, and Oxygen". Plant Physiol. 43 (8): 1255-1258. Plant Physiology is a peer-reviewed scientific journal that publishes articles on the physiology, biochemistry cellular and molecular biology genetics biophysics
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