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==Applications==
==Applications==
[[File:Velp-thermitewelding-1.jpg| thumb| left|rail track welding by thermite]]
[[File:Velp-thermitewelding-1.jpg| thumb| left|Rail track welding by thermite]]
A common use of this reaction is the welding of [[rail tracks]] on-site, useful for complex installations or local repairs that cannot be done using continuously welded rail.
A common use of this reaction is the welding of [[rail tracks]] on-site, useful for complex installations or local repairs that cannot be done using continuously welded rail.


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The aluminothermic reaction is also used for the production of most of the [[ferroalloys]], for example [[ferroniobium]] from [[niobium pentoxide]].<ref>{{cite web | title = The Production of Ferroniobium at the Niobec Mine MINE 1981-2001 | author = Claude Dufresne and Ghislain Goyette | url = http://www.cbmm.com.br/portug/sources/techlib/science_techno/table_content/sub_1/images/pdfs/start.pdf | accessdate = 2008-09-02}}</ref> Other metals can be produced in the same way.<ref name="alalloy">{{cite book | url = http://books.google.com/?id=2PAarkWieIQC&pg=PA387 | title = Aluminum and Aluminum Alloys: Aluminum and Aluminum Alloys | first = Joseph R. | last = Davis | publisher =ASM International | year = 1993 | isbn = 978-0-87170-496-2}}</ref><ref name="gupta">{{cite book | url = http://books.google.com/?id=2PAarkWieIQC&pg=PA387 | title = Chemical Metallurgy: Principles and Practice | first = Chiranjib Kumar | last = Gupta | publisher = Wiley-VCH | year = 2006 | isbn = 978-3-527-60525-5}}</ref><ref>{{cite journal | title = Thermite reactions: their utilization in the synthesis and processing of materials | journal = Journal of Materials Science | volume = 28 | issue = 14 | year = 1993 | doi = 10.1007/BF00353167 | pages = 3693&ndash;3708 | first = L. L. | last = Wang | coauthors = Munir Z. A.; Maximov,Y. M.|bibcode = 1993JMatS..28.3693W }}</ref>
The aluminothermic reaction is also used for the production of most of the [[ferroalloys]], for example [[ferroniobium]] from [[niobium pentoxide]].<ref>{{cite web | title = The Production of Ferroniobium at the Niobec Mine MINE 1981-2001 | author = Claude Dufresne and Ghislain Goyette | url = http://www.cbmm.com.br/portug/sources/techlib/science_techno/table_content/sub_1/images/pdfs/start.pdf | accessdate = 2008-09-02}}</ref> Other metals can be produced in the same way.<ref name="alalloy">{{cite book | url = http://books.google.com/?id=2PAarkWieIQC&pg=PA387 | title = Aluminum and Aluminum Alloys: Aluminum and Aluminum Alloys | first = Joseph R. | last = Davis | publisher =ASM International | year = 1993 | isbn = 978-0-87170-496-2}}</ref><ref name="gupta">{{cite book | url = http://books.google.com/?id=2PAarkWieIQC&pg=PA387 | title = Chemical Metallurgy: Principles and Practice | first = Chiranjib Kumar | last = Gupta | publisher = Wiley-VCH | year = 2006 | isbn = 978-3-527-60525-5}}</ref><ref>{{cite journal | title = Thermite reactions: their utilization in the synthesis and processing of materials | journal = Journal of Materials Science | volume = 28 | issue = 14 | year = 1993 | doi = 10.1007/BF00353167 | pages = 3693&ndash;3708 | first = L. L. | last = Wang | coauthors = Munir Z. A.; Maximov,Y. M.|bibcode = 1993JMatS..28.3693W }}</ref>

==See also==
* [[Thermic reaction]]


==References==
==References==
{{Reflist}}
{{Reflist}}

==See also==
* [[Thermic reaction]]
* [[List of Russian inventions]]
* [[Timeline of Russian inventions and technology records]]


[[Category:Inorganic reactions]]
[[Category:Inorganic reactions]]

Revision as of 09:36, 5 September 2012

An aluminothermic reaction using iron(III) oxide. The sparks flying outwards are globules of molten iron trailing smoke in their wake.

Aluminothermic reactions are exothermic chemical reactions using aluminium as the reducing agent at high temperature. The most prominent example is the thermite reaction between aluminium and iron oxides:

Fe2O3 + 2 Al → 2 Fe + Al2O3

History

Aluminothermy started from the experiments of Russian scientist Nikolay Beketov, who proved that aluminium restored metals from their oxides under high temperatures. The reaction was first used for the carbon-free reduction of metal oxides. The reaction is highly exothermic, but it has a high activation energy since strong interatomic bonds in the solids must be broken first. The oxide was heated with aluminium in a crucible in a furnace. The runaway reaction made it possible to produce only small quantities of material. Hans Goldschmidt improved the aluminothermic process between 1893 and 1898, by igniting the mixture of fine metal oxide and aluminium powder by a starter reaction without heating the mixture externally. The process was patented in 1898 and used extensively in the later years for rail track welding.

Applications

Rail track welding by thermite

A common use of this reaction is the welding of rail tracks on-site, useful for complex installations or local repairs that cannot be done using continuously welded rail.

Another common use is the welding of copper cables (wire) for use in direct burial (grounding/earthing) applications. It is still the only type of electrical connection recognized by the IEEE (IEEE, Std 80-2001) as continuous un-spliced cable.

The aluminothermic reaction is also used for the production of most of the ferroalloys, for example ferroniobium from niobium pentoxide.[1] Other metals can be produced in the same way.[2][3][4]

References

  1. ^ Claude Dufresne and Ghislain Goyette. "The Production of Ferroniobium at the Niobec Mine MINE 1981-2001" (PDF). Retrieved 2008-09-02.
  2. ^ Davis, Joseph R. (1993). Aluminum and Aluminum Alloys: Aluminum and Aluminum Alloys. ASM International. ISBN 978-0-87170-496-2.
  3. ^ Gupta, Chiranjib Kumar (2006). Chemical Metallurgy: Principles and Practice. Wiley-VCH. ISBN 978-3-527-60525-5.
  4. ^ Wang, L. L. (1993). "Thermite reactions: their utilization in the synthesis and processing of materials". Journal of Materials Science. 28 (14): 3693–3708. Bibcode:1993JMatS..28.3693W. doi:10.1007/BF00353167. {{cite journal}}: Unknown parameter |coauthors= ignored (|author= suggested) (help)

See also