Where Found (Encyclopedia of Global Resources)
Niobium is most often found as niobium pentoxide in the mineral niobite (also called columbite or tantalite), which in the United States is found in Colorado, Connecticut, Maine, North Carolina, South Dakota, and Virginia. This mineral is also found in Australia, Brazil, Canada, Madagascar, South Africa, the Democratic Republic of the Congo, Nigeria, Norway, and Russia.
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Primary Uses (Encyclopedia of Global Resources)
Niobium is used to toughen and harden steel. It is also used to make low- and high-temperature superconductors. In its Mineral Commodity Summaries (January, 2009), the U.S. Geological Survey reported that approximately 78 percent of U.S. end use of niobium is in manufacturing of steels, with the remaining 22 percent devoted to production of superalloys.
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Technical Definition (Encyclopedia of Global Resources)
Niobium (symbol Nb), or columbium (symbol Cb), has an atomic number of 41, an atomic weight of 92.9064, and sixteen isotopes. It is a hard, lustrous metal, gray or silver-white in color, malleable (capable of being bent or flattened), and ductile (capable of being stretched). It has a melting point of 2,468° Celsius, a boiling point of 4,742° Celsius, and a specific gravity of 8.4.
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Description, Distribution, and Forms (Encyclopedia of Global Resources)
Niobium is named for Niobe, the mythical daughter of the Greek god Tantalus. The designation niobium was officially adopted by the International Union of Pure and Applied Chemistry in 1949. However, an alternative name, columbium, is still used by many metallurgists in the United States and, to a lesser degree, England.
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History (Encyclopedia of Global Resources)
Niobium was discovered by the English chemist Charles Hatchett in 1801, and it was first prepared in 1864 when Christian Wilhelm Blomstrand of Sweden isolated it from niobium chloride by reduction in a stream of hydrogen. Niobium is easily welded and resists tarnish. It exhibits a variable valency of +2, +3, +5, and possibly +4. At high temperatures, it reacts with oxygen, carbon, nitrogen, sulfur, chlorine, fluorine, bromine, iodine, and other nonmetals.
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Obtaining Niobium (Encyclopedia of Global Resources)
Niobite forms in pegmatite (exceptionally coarse-grained igneous rocks typically made of granite), often with tin and tungsten minerals. Ores of niobium are also sometimes found in placer deposits. Niobium is rarely found without a similar element called tantalum. Eighty-five percent of all niobium reserves are located in Brazil. The element niobium is extracted from niobite by reducing the complex alkali fluoride with sodium, or the oxide with calcium, aluminum, or hydrogen.
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Uses of Niobium (Encyclopedia of Global Resources)
Because niobium has excellent gas-absorbing qualities and a high melting point, it is used in the manufacture of vacuum tubes. Niobium is used as an alloying agent in carbon and alloy steels. In the preparation of stainless steel, it is used to prevent corrosion at high temperatures and to permit fabrication without added heat treatment. Niobium adds strength, toughness, and ductility to chrome steel. Niobium alloys are used in jet and rocket engines. In the form of a carbide, niobium is used in making cutting tools. Combined with selenium and hydrogen, it forms a low-temperature superconductor (a material that can conduct electricity without any resistance), which is used in the construction of superconducting magnets. Applications include monorail trains, where the tracks are made of superconductor material and the trains are magnetized and glide along without any resistance. It is also combined with other elements to form high-temperature superconductors. Since niobium allows neutrons to pass through it without interference, it is used in nuclear reactors, particularly in the walls of experimental fusion reactors.
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Further Reading (Encyclopedia of Global Resources)
Natural Resources Canada. Canadian Minerals Yearbook, 1994: Niobium. http://www.nrcan.gc.ca/smm-mms/busi-indu/cmy-amc/content/1994/43.pdf
U.S. Geological Survey. Mineral Information: Niobium (Columbium) and Tantalum Statistics and Information. http://minerals.usgs.gov/minerals/pubs/commodity/niobium/
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Niobium (Chemical Elements)
Niobium is a transition metal in Group 5 (VB) of the periodic table. The periodic table is a chart that shows how chemical elements relate to one another.
Niobium has a very interesting history. It was discovered by English chemist Charles Hatchett (1765-1847) in 1801. Hatchett found the element in a stone sent from North America. He named the element columbium. For years, scientists argued about the correct name for the element. Some still call the element columbium, although the official name is now niobium.
Niobium is used in many alloys. An alloy is made by melting and mixing two or more metals. The mixture has properties different from those of the individual metals. Niobium alloys are used in items that come into contact with the human body, such as rings for pierced ears, nose, and other body parts. Niobium is used in this kind of jewelry because it does not cause allergies or other problems.
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