Niobium

Notable characteristics

Niobium is a shiny gray, ductile periodic table.

When it is processed at even moderate temperatures niobium must be placed in a protective atmosphere. The metal begins to oxidation states are +3, and +5, although others are also known.

Niobium has a number of uses: it is a component of some alloy of other nonferrous metals. It is also a very important alloy addition in HSLA steels, which are widely used as structural components in modern automobiles. These alloys are strong and are often used in pipeline construction. Other uses;

• The metal has a low capture cross-section for thermal neutrons and so finds use in the nuclear industries.
• It is also the metal used in arc welding rods for some stabilized grades of stainless steel.
• Appreciable amounts of niobium in the form of high-purity ferroniobium and superalloys for such applications as jet engine components, rocket subassemblies, and heat-resisting and combustion equipment. For example, advanced air frame systems such as those used in the Gemini program used this metal.
• Niobium is being evaluated as an alternative to tantalum in capacitors.
• Because niobium and some niobium alloys are physiologically inert (and thus hypoallergenic), they are used in jewelry and in medical devices such as pacemakers. Niobium treated with sodium hydroxide forms a porous layer that aids osseointegration.^[4]
• Along with anodized to a wide array of colors using a process known as reactive metal anodizing. This makes it very attractive for use in jewelry.
• Niobium is also added to glass in order to attain a higher refractive index, a property used in the optical industry to make thinner corrective glasses.
• In 2005, the country of Sierra Leone made a coin honoring Pope John Paul II that contained a disc of 24 carat (100%) gold surrounded by a ring of purple-tinted Niobium.

Niobium becomes a superconducting magnets capable of producing exceedingly strong magnetic fields. Niobium is also used in its pure form to make superconducting accelerating structures for particle accelerators.

History

Niobium (Greek mythology: Niobe, daughter of Tantalus) was hydrogen atmosphere.

Columbium (symbol Cb) was the name originally given to this element by Hatchett, but the International Union of Pure and Applied Chemistry (IUPAC) officially adopted "niobium" as the name for element 41 in 1950 after 100 years of controversy. This was a compromise of sorts; the IUPAC accepted tungsten instead of wolfram, in deference to North American usage; and niobium instead of columbium, in deference to European usage. Not everyone agreed, however, and while many leading chemical societies and government organizations refer to it by the official IUPAC name, many leading metallurgists, metal societies, and most leading American commercial producers still refer to the metal by the original "columbium."

Occurrence

  The element is never found as a free element but does occur in the minerals silicate igneous rocks) and as a constituent of pyrochlore. Brazil and Canada are the major producers of niobium mineral concentrates and extensive ore reserves are also in Nigeria, Democratic Republic of Congo, and in Russia. A large producer in Brazil is CBMM located in Araxá, Minas Gerais.

Isotopes

Main article: isotopes of niobium

Naturally occurring niobium is composed of one stable neutron emission occurring in the first mode of the two mode decay of Nb-104, 109 and 110.

Only Nb-95 (35 days) and Nb-97 (72 minutes) and heavier isotopes (halflives in seconds) are used nuclear fuel is slower than would be expected from its own 35 day halflife alone.. Tiny amounts of the other isotopes may be produced as direct fission products.

Precautions

Niobium-containing compounds are relatively rarely encountered by most people, but many are highly toxic and should be treated with care. Metallic niobium dust is an eye and skin irritant and also can be a fire hazard. Niobium has no known biological role.

See also

• Niobium compounds
• Niobium minerals

References

1. ^ Niobium: niobium(IV) fluoride compound data. WebElements.com. Retrieved on 2007-12-10.
2. ^ Niobium: niobium(II) oxide compound data. WebElements.com. Retrieved on 2007-12-10.
3. ^ Niobium: niobium(I) chloride compound data. Bernath.UWaterloo.ca. Retrieved on 2007-12-10.
4. ^ Godley, Reut; David Starosvetsky, and Irena Gotman (2004). "Bonelike apatite formation on niobium metal treated in aqueous NaOH" (PDF). Journal of Materials Science: Materials in Medicine 15: 1073–1077. doi:10.1023/B:JMSM.0000046388.07961.81. Retrieved on 2006-09-07.

• Los Alamos National Laboratory – Niobium