The Collaborative Dictionary

Zirconium \Zir*co"ni*um\, n. [NL.] (Chem.) A rare element of the carbon-silicon group, intermediate between the metals and nonmetals, obtained from the mineral zircon as a dark sooty powder, or as a gray metallic crystalline substance. Symbol Zr. Atomic weight, 90.4. [1913 Webster]

Word Net

zirconium n : a lustrous gray strong metallic element resembling titanium; it is used in nuclear reactors as a neutron absorber; it occurs in baddeleyite but is obtained chiefly from zircon [syn: Zr, atomic number 40]

English

Etymology

From a New Latin coinage, from zircon.

Noun

1. a metallic chemical element (symbol Zr) with an atomic number of 40.

Derived terms

• cubic zirconium oxide
• potassium zirconium fluoride
• zircaloy, zircalloy
• zirco-, zirconio-, zircono-
• zirconium carbide
• zirconium dioxide
• zirconium nitride
• zirconium oxide
• zirconium tetrachloride

Related terms

• zircon
• zircona
• zirconia
• zirconic
• zirconolite

Translations

• Afrikaans: sirkonium
• Albanian: zirkonium
• Arabic: (zirkúnyum)
• Armenian: ցիրկոնիում (ts‘irkonium)
• Basque: zirkonioa
• Belarusian: цырконiй (tsyrkónij)
• Breton: zirkoniom
• Bulgarian: цирконий (tsirkónij)
• Catalan: zirconi
• Chinese: 鋯 (gào)
• Cornish: zerconyum
• Croatian: cirkonij
• Czech: zirkonium
• Danish: zirkonium
• Dutch: zirkonium
• Esperanto: zirkonio
• Estonian: tsirkoonium
• Faroese: zirkon
• Finnish: zirkonium
• French: zirconium
• West Frisian: zirkonium
• Galician: circonio
• Georgian: ცირკონიუმი (tsirkoniumi)
• German: Zirkon , Zirkonium
• Greek, Modern: ζιρκόνιο (zirkónio)
• Hebrew: זירקוניום (zirkónyum)
• Hungarian: cirkónium
• Icelandic: sirkon
• Interlingua: zirconium
• Irish: siorcóiniam
• Italian: zirconio
• Japanese: ジルコニウム (jirukoniumu)
• Kazakh: цирконий (tsirkoniy)
• Korean: 지르코늄 (jireukonyum)
• Latvian: cirkonijs
• Lithuanian: cirkonis
• Macedonian: циркониум (tsirkónium)
• Malay: zirkonium
• Maltese: żirkonju
• Mongolian: циркони (tsirkoni)
• Norwegian: zirkonium
• Polish: cyrkon
• Portuguese: zircónio (Port.); zircônio (Brazil)
• Romanian: zirconiu
• Russian: цирконий (tsirkónij)
• Scottish Gaelic: siorcòiniam
• Serbian: циркониjум (cirkonijum)
• Slovak: zirkón
• Slovene: cirkonij
• Spanish: circonio
• Swedish: zirkonium
• Tajik: cirkoni'
• Tamil: வன்தங்கம் (van-thangam)
• Thai: (soekhōniam)
• Turkish: zirkonyum
• Ukrainian: цирконiй (tsyrkónij)
• Uzbek: цирконий (tsirkoniy)
• Vietnamese: ziriconi
• Welsh: zirconiwm

External links

For further etymology and more information refer to: http://elements.vanderkrogt.net/elem/zr.html (A lot of the translations were taken from that site with permission from the author)

See also

• baddeleyite
• hyacinth
• jacinth
• jargon
• ligure

Zirconium (, /ˌzɝˈkoʊniəm/) is a chemical element with the symbol Zr and atomic number 40. It is a lustrous, gray-white, strong transition metal that resembles titanium. Zirconium is used as an alloying agent due to its high resistance to corrosion. It is never found as a native metal, but is instead obtained mainly from the mineral zircon, which can be purified by chlorine. Zirconium was first isolated in an impure form in 1824 by Berzelius.

Zirconium has no known biological role. Zirconium forms both inorganic and organic compounds, such as zirconium dioxide and zirconocene dibromide, respectively. There are five naturally-occurring isotopes, three of which are stable. Short-term exposure to zirconium powder causes minor irritation, and inhalation of zirconium compounds can cause skin and lung granulomas.

Characteristics

Zirconium is a lustrous, grayish-white, soft, ductile, and malleable metal which is solid at room temperature, though it becomes hard and brittle at lower purities. However, it will dissolve in hydrochloric and sulfuric acid, especially when fluorine is present. Alloys with zinc become magnetic below 35 K. Zirconium has an electronegativity of 1.33 on the Pauling scale. Of the elements within d-block, Zirconium has the fourth lowest electronegativity after yttrium, lutetium, and hafnium.

Applications

Because of Zirconium's excellent resistance to corrosion, it is often used as an alloying agent in materials that are exposed to corrosive agents, such as surgical appliances, explosive primers, vacuum tube getters and filaments. Zirconium dioxide (ZrO2) is used in laboratory crucibles, metallurgical furnaces, and as a refractory material. 90% of all zirconium produced is used in nuclear reactors because of its low neutron-capture cross-section and resistance to corrosion. Zirconium alloys are used in space vehicle parts for their resistance to heat, an important quality given the extreme heat associated with atmospheric reentry. Zirconium is also a component in some abrasives, such as grinding wheels and sandpaper.

Refining

Upon being collected from coastal waters, the solid mineral zircon is purified by spiral concentrators to remove excess sand and gravel and by magnetic separators to remove ilmenite and rutile. The byproducts can then be dumped back into the water safely, as they are all natural components of beach sand. The refined zircon is then purified into pure zirconium by chlorine or other agents, then sintered until sufficiently ductile for metalworking. Arabic zarkûn from Persian zargûn زرگون meaning "gold like")

Occurrence

Geological

Zirconium has a concentration of about 130 mg/kg within the earth's crust and about .026 μg/L in sea water, and annual worldwide zirconium production is approximately 900,000 metric tons.

Zircon is a by-product of the mining and processing of the titanium minerals ilmenite and rutile, as well as tin mining. From 2003 to 2007, zircon prices have steadily increased from $360 to $840 per metric ton. This metal is commercially produced mostly by the reduction of the zirconium(IV) chloride with magnesium metal in the Kroll process. These properties make zirconia useful as a thermal barrier coating, though it is also a common diamond substitute. Other inorganic zirconium compounds include zirconium (II) hydride, zirconium nitride, and zirconium tetrachloride (ZrCl4), which is used in the Friedel-Crafts reaction.

Organozirconium chemistry is the study of compounds containing a carbon-zirconium bond. These organozirconium compounds are often employed as polymerization catalysts. The first such compound was zirconocene dibromide, prepared in 1952 by John M. Birmingham at Harvard University. Schwartz's reagent, prepared in 1970 by P. C. Wailes and H. Weigold, is a metallocene used in organic synthesis for transformations of alkenes and alkynes.

Isotopes

Naturally-occurring zirconium is composed of five isotopes. 90Zr, 91Zr, and 92Zr are stable. 94Zr has a half-life of 1.10 × 1017 years. 96Zr has half-life of 2.4 × 1019 years, making it the longest-lived radioisotope of zirconium. Of these natural isotopes, 90Zr is the most common, making up 51.45% of all zirconium. 96Zr is the least common, comprising only 2.80% of zirconium.

28 artificial isotopes of zirconium have been synthesized, ranging in atomic mass from 78 to 110. 93Zr is the longest-lived artificial isotope, with a half-life of 1.53 × 106 years. 110Zr, the heaviest isotope of Zirconium, is also the shortest-lived, with an estimated half-life of only 30 milliseconds. Radioactive isotopes at or above mass number 93 decay by β-, whereas those at or below 89 decay by β+. The only exception is 88Zr, which decays by ε. Inhalation of zirconium compounds can cause skin and lung granulomas. Zirconium aerosols can cause pulmonary granulomas. Persistent exposure to zirconium tetrachloride resulted in increased mortality in rats and guinea pigs and a decrease of blood hemoglobin and red blood cells in dogs. OSHA recommends a 5 mg/m3 time weighted average limit and a 10 mg/m3 short-term exposure limit.

See also

• Zirconium compounds

Notes

External links

• WebElements.com – Zirconium
• Los Alamos National Laboratory – Zirconium