Compounds and Elements

The Columbia Encyclopedia,... World Encyclopedia The Oxford Pocket Dictionary... The Columbia Encyclopedia,... Further reading

zirconium

The Columbia Encyclopedia, 6th ed. | 2011 | Copyright

zirconium , metallic chemical element; symbol Zr; at. no. 40; at. wt. 91.224; m.p. about 1,852°C; b.p. 4,377°C; sp. gr. 6.5 at 20°C; valence +2, +3, or +4.

Zirconium is a very strong, malleable, ductile, lustrous silver-gray metal. At ordinary temperatures it has a hexagonal close-packed crystalline structure. Its chemical and physical properties are similar to those of titanium, the element above it in Group 4 of the periodic table . Zirconium is extremely resistant to heat and corrosion. It forms a number of compounds, among them zirconate (ZrO ₃^-2 ) and zirconyl (ZrO ⁺² ) salts.

The most important compound is the oxide zirconia (ZrO ₂ ), used extensively as a refractory material in furnaces and crucibles, in ceramic glazes, and, formerly, in gas mantles. It occurs in nature as the silicate (ZrSiO ₄ ) and is used as a gemstone; it may be clear or colored, and is usually called zircon or hyacinth. Zirconium compounds also have minor uses as catalysts, in the dye, textile, plastics, and paint industries, and in pharmaceuticals such as poison ivy lotions.

The metal also has many other uses, among them in photographic flashbulbs and surgical instruments, in the removal of residual gases from electronic vacuum tubes, and as a hardening agent in alloys, especially steel. A major use of the metal is in nuclear reactors . It is employed in tubes for cladding uranium oxide fuel. It is well suited for this purpose because it is corrosion resistant and does not readily absorb thermal neutrons. It is specially purified to remove hafnium, which absorbs neutrons much more readily. It is usually alloyed with other metals to make it more corrosion resistant for these uses.

Zirconium is a fairly abundant element and is widely distributed in minerals, but it is never found uncombined in nature. It always occurs with hafnium, which has almost identical chemical properties. The chief ore is zircon (the silicate); baddeleyite (the oxide) also has some importance. Zircon is recovered (along with monazite, ilmenite, and rutile) from certain beach sands in New South Wales, Australia, and near Jacksonville, Fla. The metal is produced by the Kroll process. The zircon is treated with carbon in an electric furnace to form a cyanonitride, which is in turn treated with chlorine gas to form the volatile tetrachloride. The tetrachloride is carefully purified by sublimation in an inert atmosphere and is then chemically reduced to metal sponge by reaction with molten magnesium. The spongy metal is cleaned and further processed into ingots.

Special care is taken to exclude hydrogen, nitrogen, and oxygen, which make the metal brittle. If the metal is too brittle to be worked, it can be further purified by the Van Arkel–de Boer process, in which the crude metal is reacted with iodine to form volatile iodides that are thermally decomposed on a hot wire, resulting in pure crystalline zirconium. The commercial metal usually contains between 1% and 3% hafnium; for nuclear reactor use the hafnium is usually removed by solvent extraction from the tetrachloride. Zirconium was discovered as the oxide zirconia in the mineral zircon by M. H. Klaproth in 1789 and was first isolated in impure form by J. J. Berzelius in 1824.

Cite this article
Pick a style below, and copy the text for your bibliography.

MLA
Chicago
APA

"zirconium." The Columbia Encyclopedia, 6th ed.. 2011. Encyclopedia.com. 26 May. 2012 <http://www.encyclopedia.com>.

"zirconium." The Columbia Encyclopedia, 6th ed.. 2011. Encyclopedia.com. (May 26, 2012). http://www.encyclopedia.com/doc/1E1-zirconiu.html

"zirconium." The Columbia Encyclopedia, 6th ed.. 2011. Retrieved May 26, 2012 from Encyclopedia.com: http://www.encyclopedia.com/doc/1E1-zirconiu.html

Learn more about citation styles

zirconium

World Encyclopedia | 2005 | Copyright

zirconium (symbol Zr) Greyish-white, metallic element, one of the transition elements. Zirconium was first discovered (1789) by the German chemist Martin Klaproth, and its chief source is zircon. Lunar rocks collected during the Apollo space missions show a higher content of zirconium than Earth ones, and zirconium exists in meteorites and stars, including the Sun. Chemically similar to titanium, it is used in ceramics, and in alloys for wire and absorption of neutrons in nuclear reactors. Properties: at.no. 40; r.a.m. 91.22; r.d. 6.51; m.p. 1852°C (3366°F); b.p. 4377°C (7911°F); most common isotope Zr⁹⁰ (51.46%).

Cite this article
Pick a style below, and copy the text for your bibliography.

MLA
Chicago
APA

"zirconium." World Encyclopedia. 2005. Encyclopedia.com. 26 May. 2012 <http://www.encyclopedia.com>.

"zirconium." World Encyclopedia. 2005. Encyclopedia.com. (May 26, 2012). http://www.encyclopedia.com/doc/1O142-zirconium.html

"zirconium." World Encyclopedia. 2005. Retrieved May 26, 2012 from Encyclopedia.com: http://www.encyclopedia.com/doc/1O142-zirconium.html

Learn more about citation styles

Zr

The Oxford Pocket Dictionary of Current English | 2009 | Copyright

Zr • symb. the chemical element zirconium.

Cite this article
Pick a style below, and copy the text for your bibliography.

MLA
Chicago
APA

"Zr." The Oxford Pocket Dictionary of Current English. 2009. Encyclopedia.com. 26 May. 2012 <http://www.encyclopedia.com>.

"Zr." The Oxford Pocket Dictionary of Current English. 2009. Encyclopedia.com. (May 26, 2012). http://www.encyclopedia.com/doc/1O999-zr.html

"Zr." The Oxford Pocket Dictionary of Current English. 2009. Retrieved May 26, 2012 from Encyclopedia.com: http://www.encyclopedia.com/doc/1O999-zr.html

Learn more about citation styles

Zr

The Columbia Encyclopedia, 6th ed. | 2011 | Copyright

Zr symbol for the element zirconium .

Cite this article
Pick a style below, and copy the text for your bibliography.

MLA
Chicago
APA

"Zr." The Columbia Encyclopedia, 6th ed.. 2011. Encyclopedia.com. 26 May. 2012 <http://www.encyclopedia.com>.

"Zr." The Columbia Encyclopedia, 6th ed.. 2011. Encyclopedia.com. (May 26, 2012). http://www.encyclopedia.com/doc/1E1-Zr.html

"Zr." The Columbia Encyclopedia, 6th ed.. 2011. Retrieved May 26, 2012 from Encyclopedia.com: http://www.encyclopedia.com/doc/1E1-Zr.html

Learn more about citation styles

ZR

The Oxford Dictionary of Abbreviations | 1998 | | Copyright

ZR Irish vehicle registration for Wexford

Cite this article
Pick a style below, and copy the text for your bibliography.

MLA
Chicago
APA

FRAN ALEXANDER , PETER BLAIR , JOHN DAINTITH , ALICE GRANDISON , VALERIE ILLINGWORTH , ELIZABETH MARTIN , ANNE STIBBS , JUDY PEARSALL , and SARA TULLOCH. "ZR." The Oxford Dictionary of Abbreviations. 1998. Encyclopedia.com. 26 May. 2012 <http://www.encyclopedia.com>.

FRAN ALEXANDER , PETER BLAIR , JOHN DAINTITH , ALICE GRANDISON , VALERIE ILLINGWORTH , ELIZABETH MARTIN , ANNE STIBBS , JUDY PEARSALL , and SARA TULLOCH. "ZR." The Oxford Dictionary of Abbreviations. 1998. Retrieved May 26, 2012 from Encyclopedia.com: http://www.encyclopedia.com/doc/1O25-ZR.html

Learn more about citation styles

Zr

The Oxford Dictionary of Abbreviations | 1998 | | Copyright

Zr Chem., symbol for zirconium

Cite this article
Pick a style below, and copy the text for your bibliography.

MLA
Chicago
APA

FRAN ALEXANDER , PETER BLAIR , JOHN DAINTITH , ALICE GRANDISON , VALERIE ILLINGWORTH , ELIZABETH MARTIN , ANNE STIBBS , JUDY PEARSALL , and SARA TULLOCH. "Zr." The Oxford Dictionary of Abbreviations. 1998. Encyclopedia.com. 26 May. 2012 <http://www.encyclopedia.com>.

FRAN ALEXANDER , PETER BLAIR , JOHN DAINTITH , ALICE GRANDISON , VALERIE ILLINGWORTH , ELIZABETH MARTIN , ANNE STIBBS , JUDY PEARSALL , and SARA TULLOCH. "Zr." The Oxford Dictionary of Abbreviations. 1998. Retrieved May 26, 2012 from Encyclopedia.com: http://www.encyclopedia.com/doc/1O25-Zr.html

Learn more about citation styles

Free newspaper and magazine articles

	Biggest Zirconium Base Established in Jiangsu.(Brief Article) Magazine article from: China Chemical Reporter; 11/6/2001
	China Zirconium Announces its 2008 Annual Results.(Financial report) News Wire article from: JCN Newswires; 4/1/2009
	Synthesis and characterization of zirconium ionomer dispersions.(5th... Magazine article from: Polymer Engineering and Science; 3/1/1999