Niobium , formerly known as columbium , is a chemical element with the symbol Nb (formerly Cb) and atomic number 41. It is a soft gray, , crystals, ductile transition metals, often found in pyrochlore and columbite minerals, hence the former name of "columbium". Its name comes from Greek mythology, especially Niobe, which is the daughter of Tantalus, the namesake of tantalum. This name reflects the great similarity between the two elements in their physical and chemical properties, making them difficult to distinguish.
British chemist Charles Hatchett reported a new element similar to tantalum in 1801 and named it columbium. In 1809, the English chemist William Hyde Wollaston incorrectly concluded that tantalum and columbium are identical. The German chemist Heinrich Rose determined in 1846 that tantalum ore contained a second element, which he named niobium. In 1864 and 1865, a series of scientific findings explained that niobium and columbium were the same elements (as distinguished from tantalum), and during the second century the names were used interchangeably. Niobium was formally adopted as an elemental name in 1949, but the name columbium remains in use today in metallurgy in the United States.
It was not until the early 20th century that niobium was first used commercially. Brazil is a major producer of niobium and ferroniobium, an alloy of 60-70% niobium with iron. Niobium is used mostly in alloys, the largest part in special steels as used in gas pipelines. Although this alloy contains a maximum of 0.1%, a small percentage of niobium increases the strength of the steel. Superalloy temperature stability containing niobium is important for use in jet engines and rockets.
Niobium is used in a variety of superconducting materials. These superconducting alloys, also containing titanium and tin, are widely used in magnetic superconducting MRI scanners. Other niobium applications include welding, nuclear industry, electronics, optics, numismatics, and jewelry. In the last two applications, low toxicity and color games generated by anodization are highly desirable properties.
Video Niobium
History
Niobium was identified by the English chemist Charles Hatchett in 1801. He discovered a new element in a mineral sample that had been sent to England from Connecticut, USA in 1734 by John Winthrop F.R.S. (grandson of John Winthrop the Younger) and named the columbite mineral and columbium new elements after Columbia, the poetic name for the United States. The
Furthermore, there is great confusion over the difference between columbium (niobium) and tantalum closely related. In 1809, the English chemist William Hyde Wollaston compared the oxides derived from columbium-columbite, with a density of 5.918 g/cm 3 , and tantalum-tantalite, with a density of more than 8 g/cm 3 , and concludes that two oxides, in spite of significant differences in density, are identical; so he keeps the name of tantalum. This conclusion was debated in 1846 by the German chemist Heinrich Rose, who argued that there were two distinct elements in the tantalite sample, and named them after the children of Tantalus: niobium (from Niobe) and the pelopium (from Pelops). This confusion arises from the minimal difference observed between tantalum and niobium. New elements claimed by pelopium , ilmenium , and dianium are identical to niobium or a mixture of niobium and tantalum.
The distinction between tantalum and niobium was firmly demonstrated in 1864 by Christian Wilhelm Blomstrand and Henri Etienne Sainte-Claire Deville, and Louis J. Troost, who determined the formula of several compounds in 1865 and finally by the Swiss chemist Jean Charles Galissard de Marignac in the year 1866, all of which prove that there are only two elements. The article on ilmenium continued to appear until 1871.
De Marignac was the first to prepare the metal in 1864, when he reduced niobium chloride by heating it in the atmosphere of hydrogen. Although de Marignac was able to produce niobium tantalum-free on a larger scale in 1866, it was not until the early 20th century that niobium was used in incandescent filaments, the first commercial application. This use quickly becomes obsolete through the replacement of niobium with tungsten, which has a higher melting point. The Niobium increased the strength of steel that was first discovered in the 1920s, and this application is still used primarily. In 1961, American physicist Eugene Kunzler and colleagues at Bell Labs found that niobium-tin continued to exhibit superconductivity in the presence of powerful electric currents and magnetic fields, making it the first material to support high currents and fields required for high-useful magnetic power and electric power machine. The invention was activated - two decades later - the production of long-stranded multi-stranded cables twisted into coils to create large, powerful electromagnets for rotating machines, particle accelerators, and particle detectors.
Name the element
Columbium (the "Cb" symbol) is the name originally given by Hatchett after its discovery in 1801. The name reflects that the ore species specimens are from the United States (Columbia). The name is still used in American journals - the last paper published by the American Chemical Society with columbium in its title since 1953 while niobium is used in Europe. To end this confusion, the name niobium was selected for element 41 at the 15th Union of Chemistry Conference in Amsterdam in 1949. A year later the name was officially adopted by the International Union of Pure and Applied Chemicals (IUPAC) after 100 years of controversy, despite the chronological precedence of the name columbium . This is a compromise of sorts; IUPAC receives tungsten instead of tungsten in honor of North American usage; and niobium instead of columbium to respect European usage. While many US chemical societies and government organizations typically use the official name of IUPAC, some metallurgical experts and the metal community still use the original American name, " columbium ".
Maps Niobium
Characteristics
Physical
Niobium is a shiny, gray, ductile, and paramagnetic metal in groups 5 of the periodic table (see table), with an electron configuration in the outer shell which is atypical for group 5. (It can be observed in the ruthenium environment (44), rhodium ( 45), and palladium (46).)
Although it is thought to have a cubic body-centered crystal structure from absolute zero to its melting point, the high-resolution measurements of thermal expansion along three crystallographic axes reveal anisotropy inconsistent with cubic structures. Therefore, further research and discovery in this field is expected.
Niobium becomes superconductor at cryogenic temperature. At atmospheric pressure, it has the highest critical temperature of the elemental superconductor at 9.2Ã, K. Niobium has the greatest magnetic penetration depth of any element. In addition, it is one of three Element II superconducting types, along with vanadium and technetium. The superconductive properties depend heavily on the purity of niobium metal.
When it is very pure, it is relatively soft and ductile, but the dirt makes it more difficult.
Metals have low capture cross-section for thermal neutrons; so it is used in the nuclear industry where a transparent neutron structure is desired.
Chemistry
This metal becomes slightly bluish when exposed to air at room temperature for a long time. Despite its high melting point in elemental form (2.468 Â ° C), it has a lower density than other refractory metals. In addition, corrosion resistance, indicating the nature of superconductivity, and forming a dielectric oxide layer.
Niobium is slightly less electropositive and more compact than its predecessor in the periodic table, zirconium, whereas it is almost identical in size with heavier tantalum atoms, as a result of lanthanide contractions. As a result, the chemical properties of niobium are very similar to those of tantalum, which appear just below niobium in the periodic table. Although corrosion resistance is not as prominent as in tantalum, lower prices and greater availability make niobium attractive for less demanding applications, such as vat coating on chemical plants.
Isotope
Niobium in the Earth's crust consists of one stable isotope, 93 Nb. In 2003, at least 32 radioisotopes had been synthesized, ranging in atomic masses from 81 to 113. The most stable was 92 Nb with 34.7 million years of part time. One of the most stable is 113 Nb, with an estimated half-life of 30 milliseconds. The lighter isotope of the stable 93 Nb tends to decay with the decay of , and the heavier ones tend to decay with decay - . , with some exceptions. 81 Nb, 82 Nb, and 84 Small nb? delayed proton emission delay path, 91 Nb decays by electron capture and positron emission, and 92 Nb decays by decay and? - .
At least 25 nuclear isomers have been described, ranging in atomic masses from 84 to 104. In this range, only 96 Nb, 101 Nb, and 103 Nb does not have an isomer. The most stable of the niobium isomers is 93m Nb with a half-life of 16.13 years. The most unstable isomer is 84m Nb with a half-life of 103 s. All isotopic niobium is decomposed with isomeric transition or beta decay except 92m1 Nb, which has a minor electron capture branch.
Genesis
Niobium is thought to be the 34th most common element in the Earth's crust, with 20 ppm. Some people think that the abundance on Earth is much greater, and that the high density of the element has concentrated it in the Earth's core. The free element is not found in nature, but niobium occurs in combination with other elements in the mineral. Minerals containing niobium often also contain tantalum. Examples include columbite (Fig, Mn) (Nb, Ta) 2 O 6 ) and columbite-tantalite (or coltan , (Fe, Mn) (Ta, Nb) 2 O 6 ). Columbite-tantalite minerals are most commonly found as accessory minerals in pegmatite intrusion, and in alkali intrusive rocks. Less common are niobat calcium, uranium, thorium and rare earth elements. Examples of such niobates are pyrochlore ((Na, Ca) 2 Nb 2 O 6 (OH, F)) and euxenite ((Y, Ca , Ce, U, Th) (Nb, Ta, Ti) 2 O 6 ). These large deposits of niobium have been found to be associated with carbonatite (igneous carbonate-silicate rocks) and as pyrochloric constituents.
The three largest deposits of pirolida today, two in Brazil and one in Canada, were discovered in the 1950s, and are still the major producers of niobium mineral concentrate. The largest deposit is hosted in carbonatite intrusion in AraxÃÆ'¡, state of Minas Gerais, Brazil, owned by CBMM (Companhia Brasileira de Metalurgia e MineraÃÆ'§ÃÆ' £ o); Other active Brazil deposits are located near CatalÃÆ' £ o, the state of GoiÃÆ'¡s, and owned by China Molybdenum, also held in carbonatite intrusion. Together, both mines produce about 88% of the world's supply. Brazil also has large deposits but is still unexploited near SÃÆ' £ o Gabriel da Cachoeira, the state of Amazonas, as well as some smaller deposits, particularly in the state of Roraima.
The third largest niobium producer is the carbonateite Niobec mine, in Saint-Honorà ©, near Chicoutimi, Quebec, Canada, owned by Magris Resources. This yields between 7% and 10% of the world supply.
Production
After separation from other minerals, the tantalum oxide mixture Ta 2 O 5 and niobium Nb 2 O 5 were obtained. The first step in processing is the oxide reaction with hydrofluoric acid:
- Ta 2 O 5 14 HF -> 2 H 2 [TaF 7 ] 5 H 2 O
- Nb 2 O 5 10 HF -> 2 H 2 [Nbof 5 ] 3 H 2 O
The first industrial-scale separation, developed by de Marignac, exploits different solubility of complex niobium and tantalum fluoride, dipotassium oxypentafluoroniobate monohydrate (K 2 [Nbof 5 ] Ã, Â · H 2 O) and dipotassium heptafluorotantalate (K 2 [TaF 7 ]) in water. More recent processes use liquid extraction of fluoride from aqueous solutions by organic solvents such as cyclohexanone. The complex niobium and tantalum fluorides are extracted separately from organic solvents with water and are either precipitated by addition of potassium fluoride to produce potassium fluoride complexes, or precipitated with ammonia as pentoxides:
- H 2 2 KF -> K 2 [Nbof 5 ] ? 2 HF
Diikuti oleh:
- 2 H 2 [NbOF 5 ] 10 NH 4 OH -> Nb 2 O 5 ? 10 NH 4 F 7 H 2 O
Several methods are used for reduction to niobium metal. The electrolysis of the liquid mixture K 2 [NbOF 5 ] and the sodium chloride is one; the other is the reduction of fluoride with sodium. With this method, relatively high purity niobium can be obtained. In large-scale production, Nb 2 O 5 is reduced by hydrogen or carbon. In the aluminothermic reaction, a mixture of iron oxide and niobium oxide is reacted with aluminum:
- 3 Nb 2 O 5 Fe 2 O 3 12 Al -> 6 Nb 2 Fe 6 Al 2 O 3
Small amounts of oxidation such as sodium nitrate are added to increase the reaction. The result is aluminum oxide and ferroniobium, iron and niobium alloys used in steel production. Ferroniobium contains niobium between 60 and 70%. Without iron oxide, an aluminothermic process is used to produce niobium. Further purification is required to achieve the grade for superconductive alloys. Electron beam smelting under vacuum is a method used by two major distributors of niobium.
In 2013, CBMM from Brazil holds 85 percent of the world's niobium production. The United States Geological Survey estimates that production increased from 38,700 tons in 2005 to 44,500 tonnes in 2006. Resources worldwide are estimated at 4,400,000 tonnes. During the ten-year period between 1995 and 2005, production increased more than doubled, starting from 17,800 tons in 1995. Between 2009 and 2011, the production stabilized at 63,000 tons per year, with a slight decrease in 2012 to just 50,000 tons per year..
A lower number is found in Malawi Kanyika Deposit (Kanyika mine).
​​Compound
In many ways, niobium is similar to tantalum and zirconium. It reacts with most non-metals at high temperatures; with fluorine at room temperature; with chlorine and hydrogen at 200 ° C; and with nitrogen at 400 ° C, with products often interstitial and nonstoichiometric. The metal starts to oxidize in air at a temperature of 200 ° C. It is corrosion resistant by fused alkali and by acids, including aqua regia, hydrochloric, sulfuric acid, nitrate and phosphate. Niobium is attacked by hydrofluoric acid and a mixture of hydrofluoric acid/nitrate.
Although niobium exhibits all formal oxidation states of 5 to -1, the most common compounds have niobium in state 5. Characterally, the compound in oxidation states less than 5 indicates the Nb-Nb bond.
Oxides and sulphides
Niobium forms oxide under oxidation state 5, NbO 2 , 4 (NbO 2 ), 3 ( Nb
2 O
3 ), and a more rare oxidation state, 2 (NbO). The most common is pentoxide, a precursor for almost all niobium and alloy compounds. Niobates are produced by dissolving the pentoxide in a basic hydroxide solution or by melting it in an alkali metal oxide. Examples are lithium niobate (LiNbO 3 ) and lanthanum niobate (LaNbO 4 ). In niobate lithium there is a distorted perovskite-like structure, whereas lanthanum niobates contain lone NbO 3 - 4 ion. The niobium sulphide plated (NbS 2 ) is also known.
The material may be coated with a thin film of niobium (V) chemical vapor deposition oxide or an atomic layer deposition process, produced by the thermal decomposition of niobium (V) ethoxide above 350 ° C.
Halide
Niobium forms halides in 5 and 4 oxidation states as well as various substoichiometric compounds. The pentahalides ( NbX
5 ) displays an octahedral Nb center. Niobium pentafluoride (NbF 5 ) is a white solid with a melting point of 79.0 Â ° C and niobium pentachloride (NbCl 5 ) with a melting point 203.4 Â ° C. Both are hydrolysed to produce oxides and oxyacids, such as NbOCl 3 . The pentachloride is a versatile reagent used to produce organometallic compounds, such as niobocene dichloride ( (C
5 H
5 )
2 NbCl
2 ). Tetrahalides ( NbX
4 ) is dark colored polymers with Nb-Nb bonds; eg, black hygroscopic niobium tetrafluoride (NbF 4 ) and chocolate niobium tetrachloride (NbCl 4 ).
The anionic halide compounds of niobium are well known, in part because of Lewis acidity from pentahalides. The most important is [NbF 7 ] 2 - , the intermediate in the separation of Nb and Ta from the ore. These heptafluorides tend to form oxopentafluoride more easily than tantalum compounds. Other halide complexes include octahedral [NbCl 6 ] - :
- Nb 2 Cl 10 2 Cl - -> 2 [NbCl 6 ] -
Like other metals with low atomic numbers, various reduced halide cluster ions are known, the main example being [Nb 6 Cl 18 ] 4 - .
Nitride and carbide
Other binary compounds of niobium include niobium nitride (NbN), which becomes superconducting at low temperatures and is used in detectors for infrared light. The main Niobium carbide is NbC, a very hard, fire-resistant ceramic material, commercially used in cutting chisel bit.
Apps
Of the 44,500 tonnes of niobium mined in 2006, it is estimated that 90% is used in high-grade structural steel. The second largest application is superalloy. Superconducting Niobium alloys and electronic components are a small part of world production.
Steel production
Niobium is an effective microalloying element for steel, where it forms niobium carbide and niobium nitride. This compound enhances grain purification, and inhibits recrystallization and precipitation precipitation. This effect in turn increases the toughness, strength, shape capability, and welding capability. In micro-stainless steels, the niobium content is small (less than 0.1%) but an important addition to the high strength low alloy steel that is widely used structurally in modern cars. Niobium is sometimes used in much higher quantities for highly wear-resistant engine components and knives, as high as 3% in S110V CPM stainless steels.
This same niobium alloy is often used in pipe construction.
Superalloys
The amount of niobium is used in nickel-, cobalt-, and iron-based superalloys in proportions of 6.5% for applications such as jet engine components, gas turbines, rocket sub-assemblies, turbo charger systems, heat retardants and combustion appliances. Niobium precipitating phase hardening? '' - in the superalloy grain structure.
One example of the superalloy is the Inconel 718, which comprises about 50% nickel, 18.6% chromium, 18.5% iron, 5% niobium, 3.1% molybdenum, 0.9% titanium, and 0.4% aluminum. This superalloy is used, for example, in advanced airframe systems for Gemini programs. Other niobium alloys are used for Apollo Service Module nozzles. Since niobium is oxidized at temperatures above 400 Â ° C, a protective layer is required for this application to prevent alloys from becoming brittle.
Niobium based alloy
The alloy C-103 was developed in the early 1960s jointly by Wah Chang Corporation and Boeing Co. DuPont, Union Carbide Corp, General Electric Co. and several other companies are developing Nb-base alloys simultaneously, largely driven by the Cold War and Space Race. It consists of 89% niobium, 10% hafnium and 1% titanium and is used for liquid rocket booster nozzles, such as the main engine of Apollo Lunar Module.
Nozzle from the Merlin Vacuum series engine developed by SpaceX for the upper stage of its Falcon 9 rocket is made of niobium alloy.
The niobium reactivity with oxygen requires it to work in a vacuum or inert, which significantly increases the costs and production difficulties. Vacuum arc remelting (VAR) and electron beam melting (EBM), a new process at the time, allow the development of niobium and other reactive metals. The project that produced the C-103 began in 1959 with as many as 256 experimental niobium alloys in "C-series" (possibly from c olumbium) that could be melted as buttons and rolled into sheets. Wah Chang has a hafnium supply, which is refined from a nuclear-grade zirconium alloy, which wants to be used commercially. The 103rd experimental composition of the C-series alloy, Nb-10Hf-1Ti, has the best combination of formability and high temperatures. Wah Chang fabricated the first 500-lb C-103 heat in 1961, ingot into the sheet, using EBM and VAR. Such applications include turbine engines and liquid metal heat exchangers. The competitive niobium alloys of that era include FS85 (Nb-10W-28Ta-1Zr) from Fansteel Metallurgical Corp., Cb129Y (Nb-10W-10Hf-0.2Y) from Wah Chang and Boeing, Cb752 (Nb-10W-2.5Zr) from Union Carbide, and Nb1Zr from Superior Tube Co.
Superconducting magnets
Niobium-germanium ( Nb
3 Ge ), niobium-tin ( Nb
3 Sn ), as well as niobium-titanium alloys are used as superconducting type II wires for superconducting magnets. This superconducting magnet is used in magnetic resonance imaging and nuclear magnetic resonance instruments as well as in particle accelerators. For example, the Large Hadron Collider uses 600 tons of superconducting strands, while the International Thermonuclear Experimental Reactor uses about 600 tons of Nb 3 Sn and 250 tons of NbTi strands. In 1992 alone, more than US $ 1 billion of magnetic resonance imaging systems were clinically constructed with niobium-titanium wire.
Other superconductors
The superconducting radio frequency cavity (SRF) used in electron-free FLASH lasers (the result of a canceled TESLA linear accelerator project) and XFEL are made of pure niobium. A cryomodule team at Fermilab uses the same SRF technology from the FLASH project to develop a 1,3 GHz nine cell SRF cavity made of pure niobium. The cavity will be used in a 30-kilometer linear particle accelerator of the International Linear Collider. The same technology will be used in LCLS-II at SLAC National Accelerator Laboratory and PIP-II in Fermilab.
High-sensitivity superconductors of the niobium nitride caliber make them the ideal detector for electromagnetic radiation in the THz frequency band. These detectors were tested at the Submillimeter Telescope, the South Pole Telescope, the Lab Telescope Receiver, and at APEX, and are now used in HIFI instruments aboard the Herschel Space Observatory.
Other uses
Electroceramics
Lithium niobate, which is ferroelectric, is widely used in cellular phones and optical modulators, and for the manufacture of surface acoustic wave devices. It belongs to ABO 3 ferroelectric structures such as lithium tantalate and barium titanate. Niobium capacitors are available as an alternative to tantalum capacitors, but tantalum capacitors still dominate. Niobium is added to the glass to obtain a higher refractive index, thus allowing thinner and lighter corrective sunglasses.
The hypoallergenic app: drugs and jewelry
Niobium and some niobium alloys are physiologically inert and hypoallergenic. For this reason, niobium is used in prosthetics and implant devices, such as pacemakers. Niobium treated with sodium hydroxide form a porous layer that helps osseointegration.
Like titanium, tantalum, and aluminum, niobium can be heated and anodized ("reactive metal anodizing") to produce a variety of colors for jewelry, where the hypoallergenic properties are highly desirable.
Numismatic
Niobium is used as a precious metal in warning coins, often with silver or gold. For example, Austria produced a series of silver Niobium silver coins starting in 2003; the color in this coin is made by the diffraction of light by a thin anodized oxide layer. In 2012, ten coins are available that show the various colors in the center of the coin: blue, green, brown, purple, purple, or yellow. Two more examples are the commemorative coins of the Austrian Railway Railway EUR25 150 The Alpine Semmering year, and the commemorative coin of Europe's European EUR25 Satellite Navigation 2006. Austrian Mint produced for Latvia a series of similar coins starting in 2004, with the following one in 2007. In 2011, The Royal Canadian Mint commenced the production of $ 5 sterling silver and niobium coins called Hunter's Moon where niobium has been selectively oxidized, thus creating a unique ending in which no two coins are exactly alike.
More
The arc-tube seal of a high pressure sodium sodium lamp is made of niobium, sometimes mixed with 1% zirconium; niobium has a very similar thermal expansion coefficient, suitable for sintered alumina arc sintered tubes, translucent materials that resist chemical attack or reduction by hot sodium liquid and sodium vapor contained in operating lamps.
Niobium is used in arc welding rods for several stainless steel and anode levels for cathodic protection systems in some water tanks, which are usually coated with platinum.
Niobium is an important component of high-performance heterogene catalysts for the production of acrylic acid with selective propane oxidation.
Precautions
Niobium has no known biological role. While niobium dust is the eye and skin irritation and potential fire hazard, the niobium element on a larger scale is physiologically inert (and thus hypoallergenic) and harmless. These are often used in jewelry and have been tested for use in some medical implants.
Compounds containing Niobium are rare for most people, but some are toxic and should be treated with caution. Short and long-term exposures to niobate and niobium chloride, two water-soluble chemicals, have been tested in mice. Mice treated with one injection of niobium pentachloride or niobat showed median lethal dose (LD 50 ) between 10 and 100 mg/kg. For oral administration, the toxicity is lower; a study with mice yielded LD 50 after seven days 940 mg/kg.
References
External links
- Los Alamos National Laboratory - Niobium
- Tantalum-Niobium International Study Center
- Niobium for particle accelerators eg ILC. 2005
- Ã, "Columbium". EncyclopÃÆ'Â|dia Britannica (issue 11). 1911.
- Ã, Gilman, D. C.; Peck, H. T.; Colby, F. M., eds. (1905). "Columbium". New International Encyclopedia (issue 1). New York: Dodd, Mead.
- Niobium on Periodic Video Table (University of Nottingham)
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