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Rhenium



 
 
Rhenium is a chemical element
Chemical element

A chemical element is a type of atom that is distinguished by its atomic number; that is, by the number of protons in its atomic nucleus. The term is also used to refer to a pure chemical Chemical substance composed of atoms with the same number of protons....
 with the symbol Re and atomic number
Atomic number

In chemistry and physics, the atomic number is the number of protons found in the atomic nucleus of an atom. It is conventionally represented by the symbol Z....
 75. A rare silvery-white, heavy, polyvalent
Polyvalent

Polyvalent is a synonym for multivalent and denotes something which has many values, meanings or appeals. The metaphoric origin of...
 transition metal
Transition metal

In chemistry, the term transition metal has two possible meanings:*It commonly refers to any element in the d-block of the periodic table, including the group 12 element elements zinc, cadmium and Mercury ....
, rhenium resembles manganese
Manganese

Manganese is a chemical element, designated by the symbol Mn. It has the atomic number 25. It is found as a Oxidation state in nature , and in many minerals....
 chemically, and is used in some alloy
Alloy

An alloy is a partial or complete solid solution of one or more chemical element in a metallic matrix. Complete solid solution alloys give single solid phase microstructure, while partial solutions give two or more phases that may be homogeneous in distribution depending on thermal history....
s. Rhenium is obtained as a by-product
By-product

A by-product is a secondary or incidental product deriving from a manufacturing process, a chemical reaction or a biochemical pathway, and is not the primary product or service being produced....
 of molybdenum
Molybdenum

Molybdenum , is a Group 6 element chemical element with the symbol Mo and atomic number 42. It has the List of elements by melting point melting point of any element....
 refinement, and rhenium-molybdenum alloys are superconducting
Superconductivity

Superconductivity is a phenomenon occurring in certain materials generally at very low temperatures, characterized by exactly zero electrical resistance and the exclusion of the interior magnetic field ....
. It was the last naturally occurring stable element to be discovered and is among the ten most expensive metals on Earth, at times exceeding US$ 12,000 per kilogram
Kilogram

The kilogram or kilogrammeThe spelling kilogram is used by the International Committee for Weights and Measures and the U.S....
.

ium (Latin
Latin

Latin is an Italic language, historically spoken in Latium and Ancient Rome. Through the Military history of the Roman Empire, Latin spread throughout the Mediterranean and a large part of Europe....
 Rhenus meaning "Rhine
Rhine

File:Swiss Grand Canyon.jpgThe Rhine is one of the longest and most important rivers in Europe, at , with an average discharge of more than ....
") was the next-to-last naturally occurring element to be discovered and the last element to be discovered having a stable isotope.






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Encyclopedia


Rhenium is a chemical element
Chemical element

A chemical element is a type of atom that is distinguished by its atomic number; that is, by the number of protons in its atomic nucleus. The term is also used to refer to a pure chemical Chemical substance composed of atoms with the same number of protons....
 with the symbol Re and atomic number
Atomic number

In chemistry and physics, the atomic number is the number of protons found in the atomic nucleus of an atom. It is conventionally represented by the symbol Z....
 75. A rare silvery-white, heavy, polyvalent
Polyvalent

Polyvalent is a synonym for multivalent and denotes something which has many values, meanings or appeals. The metaphoric origin of...
 transition metal
Transition metal

In chemistry, the term transition metal has two possible meanings:*It commonly refers to any element in the d-block of the periodic table, including the group 12 element elements zinc, cadmium and Mercury ....
, rhenium resembles manganese
Manganese

Manganese is a chemical element, designated by the symbol Mn. It has the atomic number 25. It is found as a Oxidation state in nature , and in many minerals....
 chemically, and is used in some alloy
Alloy

An alloy is a partial or complete solid solution of one or more chemical element in a metallic matrix. Complete solid solution alloys give single solid phase microstructure, while partial solutions give two or more phases that may be homogeneous in distribution depending on thermal history....
s. Rhenium is obtained as a by-product
By-product

A by-product is a secondary or incidental product deriving from a manufacturing process, a chemical reaction or a biochemical pathway, and is not the primary product or service being produced....
 of molybdenum
Molybdenum

Molybdenum , is a Group 6 element chemical element with the symbol Mo and atomic number 42. It has the List of elements by melting point melting point of any element....
 refinement, and rhenium-molybdenum alloys are superconducting
Superconductivity

Superconductivity is a phenomenon occurring in certain materials generally at very low temperatures, characterized by exactly zero electrical resistance and the exclusion of the interior magnetic field ....
. It was the last naturally occurring stable element to be discovered and is among the ten most expensive metals on Earth, at times exceeding US$ 12,000 per kilogram
Kilogram

The kilogram or kilogrammeThe spelling kilogram is used by the International Committee for Weights and Measures and the U.S....
.

History

Rhenium (Latin
Latin

Latin is an Italic language, historically spoken in Latium and Ancient Rome. Through the Military history of the Roman Empire, Latin spread throughout the Mediterranean and a large part of Europe....
 Rhenus meaning "Rhine
Rhine

File:Swiss Grand Canyon.jpgThe Rhine is one of the longest and most important rivers in Europe, at , with an average discharge of more than ....
") was the next-to-last naturally occurring element to be discovered and the last element to be discovered having a stable isotope. The existence of a yet undiscovered element at this position in the periodic table
Periodic table

The periodic table of the chemical elements is a table method of displaying the chemical elements. Although precursors to this table exist, its invention is generally credited to Russian chemist Dmitri Mendeleev in 1869....
 had been predicted by Henry Moseley
Henry Moseley

Henry Gwyn Jeffreys Moseley was an England physics. His main contributions to science were the quantitative justification of the previously empirical concept of atomic number, and Moseley's law....
 in 1914. It is generally considered to have been discovered by Walter Noddack
Walter Noddack

Walter Noddack was a German chemist. He, Ida Tacke , and Otto Berg reported the discovery of Technetium and Rhenium in 1925....
, Ida Tacke, and Otto Berg
Otto Berg (scientist)

Otto Berg was one of the scientists who is considered to have discovered rhenium, the next-to-last naturally occurring element to be discovered and the last element to be discovered having a stable isotope....
 in Germany
Germany

Germany , officially the Federal Republic of Germany , is a country in Central Europe. It is bordered to the north by the North Sea, Denmark, and the Baltic Sea; to the east by Poland and the Czech Republic; to the south by Austria and Switzerland; and to the west by France, Luxembourg, Belgium, and the Netherlands....
. In 1925 they reported that they detected the element in platinum ore and in the mineral columbite. They also found rhenium in gadolinite
Gadolinite

Gadolinite is a mineral of a nearly black color and vitreous Lustre , and consisting principally of the Silicate minerals of cerium, lanthanum, neodymium, yttrium, beryllium, and iron with formula: 2ironberyllium2silicon2oxygen10....
 and molybdenite
Molybdenite

Molybdenite is a mineral of molybdenum disulfide, molybdenumsulfur2. Similar in appearance and feel to graphite, molybdenite has a lubricating effect that is a consequence of its layered structure....
. In 1928 they were able to extract 1 g of the element by processing 660 kg of molybdenite. The process was so complicated and the cost so high that production was discontinued until early 1950 when tungsten-rhenium and molybdenum-rhenium alloys were prepared. These alloys found important applications in industry that resulted in a great demand for the rhenium produced from the molybdenite fraction of porphyry copper
Copper

Copper is a chemical element with the symbol Cu and atomic number 29.It is a ductile metal with very high thermal and electrical conductivity....
 ores.

In 1908, Japan
Japan

Japan is an island country in East Asia. Located in the Pacific Ocean, it lies to the east of the Sea of Japan, People's Republic of China, North Korea, South Korea and Russia, stretching from the Sea of Okhotsk in the north to the East China Sea and Taiwan in the south....
ese chemist Masataka Ogawa
Masataka Ogawa

was a Japanese chemist known for the discovery of rhenium, which he named nipponium.After graduating from the University of Tokyo, he studied under William Ramsay in London, where he worked on the analysis of the rare mineral thorianite....
 announced that he discovered the 43rd element, and named it nipponium (Np) after Japan
Japan

Japan is an island country in East Asia. Located in the Pacific Ocean, it lies to the east of the Sea of Japan, People's Republic of China, North Korea, South Korea and Russia, stretching from the Sea of Okhotsk in the north to the East China Sea and Taiwan in the south....
 (which is Nippon in Japanese). However, later analysis indicated the presence of rhenium (element 75), not element 43
Technetium

Technetium is the lightest chemical element with no stable isotope. It is a synthetic element with the atomic number 43 and is given the symbol Tc....
. The symbol Np was later used for the element neptunium
Neptunium

Neptunium is a chemical element with the symbol Np and atomic number 93. A radioactivity metallic element, neptunium is the first transuranic element and belongs to the actinide series....
.

Characteristics

Rhenium is a silvery white metal with one of the highest melting point
Melting point

The melting point of a solid is the temperature range at which it changes states of matter from solid to liquid. At the melting point the solid and liquid phase exist in equilibrium....
s of all elements, exceeded by only tungsten
Tungsten

Tungsten , also known as wolfram , is a chemical element that has the symbol W and atomic number 74.A steel-gray metal, tungsten is found in several ores, including wolframite and scheelite....
 and carbon
Carbon

Carbon is a chemical element with chemical symbol C and atomic number 6. As a member of group 14 on the periodic table, it is nonmetallic and tetravalence?making four electrons available to form covalent bond chemical bonds....
. It is also one of the densest, exceeded only by platinum
Platinum

Platinum is a chemical element with the chemical symbol Pt and an atomic number of 78. Its name is derived from the Spanish term platina del Pinto, which is literally translated into "little silver of the Pinto River." It is in Group 10 of the periodic table of elements....
, iridium
Iridium

Iridium is the chemical element with atomic number 77, and is represented by the symbol Ir. A very hard, brittle, silvery-white transition metal of the platinum group, iridium is the second densest element and is the most corrosion-resistant metal, even at temperatures as high as 2000 ?C....
 and osmium
Osmium

Osmium is a chemical element that has the symbol Os and atomic number 76. Osmium is a hard, brittle, blue-gray or blue-black transition metal in the platinum family, and is the densest natural element....
. Rhenium has the widest range of oxidation state
Oxidation state

In chemistry, the oxidation state is an indicator of the degree of oxidation of an atom in a chemical compound. The formal oxidation state is the hypothetical Electrical charge that an atom would have if all bonds to atoms of different elements were 100% Ionic bond....
s of any known element: -3, -2, -1, 0, +1, +2, +3, +4, +5, +6 and +7. The oxidation states +7, +6, +4, +2 and -1 are the most common.

Its usual commercial form is a powder, but this element can be consolidated by pressing and resistance-sintering in a vacuum or hydrogen
Hydrogen

Hydrogen is the chemical element with atomic number 1. It is represented by the chemical symbol H. At standard temperature and pressure, hydrogen is a colorless, odorless, nonmetallic, tasteless, highly combustion and explosive Diatomic molecule gas with the molecular formula H2....
 atmosphere. This procedure yields a compact shape that is in excess of 90 percent of the density of the metal. When annealed
Annealing (metallurgy)

Annealing, in metallurgy and materials science, is a heat treatment wherein a material is altered, causing changes in its properties such as strength and hardness....
 this metal is very ductile and can be bent, coiled, or rolled. Rhenium-molybdenum alloy
Alloy

An alloy is a partial or complete solid solution of one or more chemical element in a metallic matrix. Complete solid solution alloys give single solid phase microstructure, while partial solutions give two or more phases that may be homogeneous in distribution depending on thermal history....
s are superconductive at 10 K
Kelvin

The kelvin is a Units of measurement of temperature and is one of the seven SI base units. The Kelvin scale is a Thermodynamic temperature scale where absolute zero, the theoretical absence of all thermal energy, is zero ....
; tungsten-rhenium alloys are also superconductive, around 4-8 K depending on the alloy. Rhenium metal superconducts at 2.4 K.

Isotopes

Naturally occurring rhenium is 37.4% 185Re, which is stable
Stable isotope

Stable isotopes are chemical Isotope that are not radioactive . By this definition, there are 256 known stable isotopes of the 80 elements which have one or more stable isotopes....
, and 62.6% 187Re, which is unstable
Radionuclide

A radionuclide is an atom with an unstable Atomic nucleus, which is a nucleus characterized by excess energy which is available to be imparted either to a newly-created radiation particle within the nucleus, or else to an atomic electron ....
 but has a very long half-life
Half-life

The half-life of a quantity whose value decreases with time is the interval required for the quantity to decay to half of its initial value. The concept originated in describing how long it takes atoms to undergo radioactive decay but also applies in a wide variety of other situations....
 which can be affected by its electron density. The beta decay
Beta decay

In nuclear physics, beta decay is a type of radioactive decay in which a beta particle is emitted. In the case of electron emission, it is referred to as beta minus , while in the case of a positron emission as beta plus ....
 of 187Re is used for rhenium-osmium dating
Rhenium-osmium dating

Rhenium-Osmium dating is a form of radiometric dating based on the beta decay of the isotope 187rhenium which usually has a half life of 4.16?1010 y to 187Osmium....
 of ores. The available energy for this beta decay (2.6 keV
Kev

Kev can refer to:*Chav, a social group in the United Kingdom.*Kiloelectronvolt, a unit of energy who symbol is "KeV".*Kevin, a given name occasionally shortened to "Kev"....
) is the lowest known among all radionuclide
Radionuclide

A radionuclide is an atom with an unstable Atomic nucleus, which is a nucleus characterized by excess energy which is available to be imparted either to a newly-created radiation particle within the nucleus, or else to an atomic electron ....
s. There are twenty-six other radioactive isotopes of rhenium recognized.

Compounds


The most common rhenium compounds are the oxides and the halogenides. The broad oxidation number spectrum is also visible in this compounds. Re2O7
Rhenium(VII) oxide

Rhenium oxide is the chemical compound with the formula RheniumOxygen. It is the anhydride of the hypothetical acid . Perrhenic acid, Re2O7·2H2O, however is closely related structurally to Re2O7....
, ReO3, Re2O5, ReO2
Rhenium(IV) oxide

Rhenium oxide or rhenium dioxide is the chemical compound composed of rhenium and oxygen with the chemical formula ReO2. This gray to black crystalline solid is a laboratory reagent that can be used as a catalyst....
, and Re2O3 are the known oxides. ReF7
Rhenium heptafluoride

Rhenium heptafluoride is the compound with the formula ReF7. It is a yellow low melting solid, and is the only thermally stable metal heptafluoride....
, ReCl6, ReCl5
Rhenium pentachloride

Rhenium pentachloride is a compound of rhenium and chlorine. It is a red-brown solid that is very air sensitive and reacts with water to give hydrogen chloride....
, ReCl4 and ReCl3
Rhenium trichloride

Rhenium trichloride is a chemical compound of rhenium and chlorine. It was first discovered in 1932 by Geilnann, Wriuce, and Biltz....
 are a few of the known halogen derivates. The analogous sulfide
Sulfide

The term sulfide refers to several types of chemical compounds containing sulfur in its lowest oxidation number of −2.Formally, "sulfide" is the dianion, S2−, which exists in strongly alkaline aqueous solutions formed from H2S or alkali metal salts such as Li2S, Na2S, and K2...
s, ReS2 and Re2S7 are known as well.

Rhenium is most available commercially as the sodium
Sodium perrhenate

Sodium perrhenate is a white crystalline solid. It is a commonly available precursor for rhenium compounds....
 and ammonium perrhenate
Ammonium perrhenate

Ammonium perrhenate is the ammonium salt of perrhenic acid, NH4ReO4. This is the most common form in which rhenium is traded....
s. It is also readily available as dirhenium decacarbonyl
Dirhenium decacarbonyl

Dirhenium decacarbonyl is an inorganic compound with the formula Re210. Commercially available, it is used as a starting point for the synthesis of many rhenium carbonyl complexes....
; these three compounds are common entry points to rhenium chemistry. Various perrhenate salts may be easily converted to tetrathioperrhenate by the action of ammonium hydrosulfide. Dirhenium decacarbonyl
Dirhenium decacarbonyl

Dirhenium decacarbonyl is an inorganic compound with the formula Re210. Commercially available, it is used as a starting point for the synthesis of many rhenium carbonyl complexes....
 may be oxidatively cleaved with bromine
Bromine

Bromine , , meaning "stench " ), is a chemical element with the symbol Br and atomic number 35. A halogen element, bromine is a reddish-brown Volatility liquid at Standard conditions for temperature and pressure that is intermediate in reactivity between chlorine and iodine....
 to give bromopentacarbonylrhenium(I)
Bromopentacarbonylrhenium(I)

Bromopentacarbonylrhenium is an inorganic compound of rhenium, commonly used for the syntheses of other rhenium complexes....
, then reduced with zinc
Zinc

Zinc is a metallic chemical element with the symbol Zn and atomic number 30. It is a first-row transition metal of the group 12 element of the periodic table....
 and acetic acid
Acetic acid

Acetic acid, CH3COOH, also known as ethanoic acid, is an organic acid which gives vinegar its sour taste and pungent smell. Pure, water-free acetic acid is a colourless liquid that absorbs water from the environment , and freezes at 16.7 Celsius to a colourless crystalline solid....
 to pentacarbonylhydridorhenium
Pentacarbonylhydridorhenium

Pentacarbonylhydridorhenium is a chemical compound with the chemical formula ReH5. This colorless liquid is a weak acid and represents one of the most important derivatives of dirhenium decacarbonyl ....
:

Re2(CO)10 + Br2 → Re(CO)5Br
Re(CO)5Br + Zn + HOAc → Re(CO)5H + ZnBr(OAc)


Bromopentacarbonylrhenium(I) may be decarbonylated to give the rhenium tricarbonyl fragment either by refluxing in water:

Re(CO)5Br + 3 H2O → [Re(CO)3(H2O)3]Br + 2 CO


or by reacting with tetraethylammonium bromide
Tetraethylammonium bromide

Tetraethylammonium bromide is a quaternary ammonium salt. It is a common source for the tetraethylammonium cation....
:

Re(CO)5Br + 2 (NEt4Br → [NEt4]2[Re(CO)3Br3]


Rhenium diboride
Rhenium diboride

Rhenium diboride is a synthetic superhard material. It was discovered by a team at University of California, Los Angeles and announced in Science in April 2007....
 (ReB2) is an extremely hard compound. It can actually scratch diamond, giving it a higher than 10 rank in the Mohs scale of mineral hardness and making it one of the three hardest substances known to man - the other two being ultrahard fullerite and aggregated diamond nanorods
Aggregated diamond nanorods

Aggregated diamond nanorods, or ADNRs , is a nanocrystalline form of diamond believed to be the Hardness and least compressible known material, as measured by its isothermal bulk modulus; aggregated diamond nanorods have a modulus of 491 gigapascals , while a conventional diamond has a modulus of 442 GPa....
.

Occurrence

Rhenium is probably not found free in nature (its possible natural occurrence is uncertain), but occurs in amounts up to 0.2% in the mineral molybdenite, the major commercial source. It was only recently that the first rhenium mineral
Mineral

A mineral is a naturally occurring solid formed through Geology processes that has a characteristic chemical composition, a highly ordered atomic structure, and specific physical properties....
 was found and described (in 1994), a rhenium sulfide mineral
Sulfide mineral

A sulfide mineral is a mineral containing sulfide as the major anion. Sulfides are economically important as metal ores. The sulfide class also includes the selenide mineral, the telluride mineral, the arsenide mineral, the antimonide mineral, the bismuthinides, and the sulfosalts ....
 (ReS2) condensing from a fumarole
Fumarole

A fumarole is an opening in Earth's Crust , often in the neighborhood of volcanoes, which emits steam and gases such as carbon dioxide, sulfur dioxide, hydrochloric acid, and hydrogen sulfide....
 on Russia
Russia

Russia , or the Russian Federation , is a list of countries spanning more than one continent country extending over much of northern Eurasia....
's Kudriavy volcano, in the Kurile Islands. Named rheniite
Rheniite

Rheniite is a very rare rhenium sulfide mineral . It forms metallic, silver grey platey crystals in the Triclinic - pinacoidal class. It has a specific gravity of 7.5....
, this rare mineral commands high prices among collectors, but is not an economically viable source of the element. Rhenium is widely spread through the Earth
Earth

Earth is the third planet from the Sun. Earth is the largest of the terrestrial planets in the Solar System in diameter, mass and density. It is also referred to as the World and Wiktionary:Terra.Note that by International Astronomical Union convention, the term "Terra" is used for naming extensive land masses, rather...
's crust
Crust (geology)

In geology, a crust is the outermost solid shell of a planet or moon, which is chemically distinct from the underlying mantle . Crusts of Earth , our Moon, Mercury , Venus, and Mars have been generated largely by igneous processes, and these crusts are richer in incompatible elements than their respective mantle s....
 at approximately 1 ppb
Parts-per notation

?Parts-per? notation is used, especially in science and engineering, to denote Proportionality in measured quantities; particularly in low-value proportions at the parts-per-million , parts-per-billion , and parts-per-trillion level....
. Chile
Chile

Chile, officially the Republic of Chile , is a country in South America occupying a long and narrow coastal strip wedged between the Andes mountains and the Pacific Ocean....
 has the world's largest reserves, part of the copper ore deposits, and was the leading producer as of 2005.




Production

Ammonium Perrhenate
Commercial rhenium is extracted from molybdenum roaster-flue gas obtained from copper-sulfide ores. Some molybdenum ores contain 0.002% to 0.2% rhenium. Rhenium(VII) oxide
Rhenium(VII) oxide

Rhenium oxide is the chemical compound with the formula RheniumOxygen. It is the anhydride of the hypothetical acid . Perrhenic acid, Re2O7·2H2O, however is closely related structurally to Re2O7....
 and perrhenic acid
Perrhenic acid

Perrhenic acid is the chemical compound with the formula Re2O72. It is obtained by evaporating aqueous solutions of Re2O7....
 readily dissolve in water; they are leached from flue dusts and gasses and extracted by precipitating with potassium
Potassium chloride

The chemical compound potassium chloride is a metal halide Salt composed of potassium and chlorine. In its pure state it is odorless. It has a white or colorless vitreous crystal, with a crystal structure that cleaves easily in three directions....
 or ammonium chloride
Ammonium chloride

Ammonium chloride is, in its pure form, a clear white water-soluble crystalline salt of ammonia. The aqueous ammonium chloride solution is mildly acidic....
 as the perrhenate
Perrhenate

The perrhenate ion is ReO4− and is a compound containing this ion. Salts of perrhenic acid are known as perrhenates....
 salts, and purified by recrystallization
Recrystallization

Recrystallization is a physical process that has meanings in chemistry, metallurgy and geology....
. Total world production is between 40 and 50 tons/year; the main producers are in Chile, USA and Kazakhstan. Recycling of used Pt-Re catalyst and special alloys allow the recovery of another 10 tons/year. Prices for the metal rose rapidly in early 2008, from a price of $1000-$2000 per kg
Kilogram

The kilogram or kilogrammeThe spelling kilogram is used by the International Committee for Weights and Measures and the U.S....
 in 2003-2006 to over $10,000 in February 2008. The metal form is prepared by reducing ammonium perrhenate
Ammonium perrhenate

Ammonium perrhenate is the ammonium salt of perrhenic acid, NH4ReO4. This is the most common form in which rhenium is traded....
 with hydrogen
Hydrogen

Hydrogen is the chemical element with atomic number 1. It is represented by the chemical symbol H. At standard temperature and pressure, hydrogen is a colorless, odorless, nonmetallic, tasteless, highly combustion and explosive Diatomic molecule gas with the molecular formula H2....
 at high temperatures:

2 NH4ReO4 + 7 H2 → 2 Re + 8 H2O + 2 NH3


Applications

Engine
This element is used in high-temperature superalloys that are used to make jet engine
Jet engine

A jet engine is a reaction engine that discharges a fast moving jet of fluid to generate thrust in accordance with Isaac Newton Newton's laws of motion....
 parts, making 70% of the worldwide production, and in platinum-rhenium catalysts which in turn are primarily used in making lead
Lead

Lead is a main-group Chemical element with symbol Pb and atomic number 82. Lead is a soft, malleable poor metal, also considered to be one of the heavy metal ....
-free, high-octane gasoline
Gasoline

File:GasCan.jpgGasoline or petrol is a petroleum-derived liquid mixture, primarily used as fuel in internal combustion engines.It consists mostly of aliphatic hydrocarbons, enhanced with iso-octane or the aromatic hydrocarbons toluene and benzene to increase its octane rating....
.

Superalloys

The nickel-based superalloys have improved creep strength with the addition of rhenium. The alloys normally contain 3% or 6% of rhenium. The second generation alloys contain 3%, these alloys were used in the engine of the F-16 and F-15, while the new single crystal third generation alloys contain 6% of rhenium, they are used in the F-22 and F-35 engines. For 2006 the consumption is given as 28% for General Electric
General Electric

The General Electric Company, or GE is a multinational corporation United States technology and Service s conglomerate incorporated in the State of New York....
, 28% Rolls-Royce plc
Rolls-Royce plc

Rolls-Royce Public limited company is a United Kingdom aircraft engine maker, and the second-largest in the world, behind GE Aviation. The company has related businesses in the defence aerospace, marine and energy markets....
 and 12% Pratt & Whitney
Pratt & Whitney

Pratt & Whitney is an American aircraft engine manufacturer of products widely used in both civil and military aircraft list. As one of the "big three" aero-engine manufacturers, it competes with GE Aircraft Engines and Rolls-Royce plc, although it has also formed joint ventures with both of these companies....
, all for superalloys, while the use for catalysts only accounts for 14% and the remaining applications use 18%. In 2006, 77% of the rhenium consumption in the United States was due to the use in alloys.

Catalysts


Rhenium is used as rhenium-platinum alloy as catalyst for catalytic reforming
Catalytic reforming

Catalytic reforming is a chemical process used to convert petroleum refinery naphthas, typically having low octane ratings, into high-octane liquid products called reformates which are components of high-octane gasoline ....
, which is a chemical process used to convert petroleum refinery naphtha
Naphtha

Naphtha normally refers to a number of different flammable liquid mixtures of hydrocarbons, i.e. a distillation product from petroleum or coal tar boiling in a certain range and containing certain hydrocarbons, a broad term encompassing any volatile, flammable liquid hydrocarbon mixture....
s, with low octane rating
Octane rating

The octane rating is a measure of the resistance of gasoline and other fuels to detonation in spark plug internal combustion engines. High-performance engines typically have higher compression ratios and are therefore more prone to detonation, so they require higher octane fuel....
s, into high-octane liquid products. World wide 30% of catalysts used for this process contain rhenium. The olefin metathesis
Olefin metathesis

Olefin metathesis or transalkylidenation is an organic reaction that entails redistribution of alkylene fragments by the scission of carbon - carbon chemical bond in olefins....
 is the other reaction for which rhenium is used as catalyst. Normally Re2O7 on alumina is used for this process.

Other uses


  • Widely used as filaments in mass spectrographs and in ion gauges.
  • An additive to tungsten and molybdenum-based alloys to increase ductility in these alloys.
  • An additive to tungsten in some x-ray
    X-ray

    X-radiation is a form of electromagnetic radiation. X-rays have a wavelength in the range of 10 to 0.01 nanometers, corresponding to frequency in the range 30 Hertz to 30 Hertz and energies in the range 120 Electron volt to 120 keV....
     sources.
  • Rhenium catalysts are very resistant to chemical poisoning
    Catalyst poisoning

    Catalyst poisoning refers to the effect that a catalyst can be 'poisoned' if it reacts with another chemical compound that bond but does not release, or chemically alters the catalyst....
    , and so are used in certain kinds of hydrogenation reactions.
  • Electrical contact
    Switch

    In electronics, a switch is an electrical component which can break an electrical circuit, interrupting the Electric current or diverting it from one conductor to another....
     material due to its good wear resistance
    Wear

    In materials science, wear is the erosion of material from a solid surface by the action of another substance. The study of the processes of wear is part of the discipline of tribology....
     and ability to withstand arc corrosion.
  • Thermocouple
    Thermocouple

    A thermocouple is a junction between two different metals that produces a voltage related to a temperature difference. Thermocouples are a widely used type of list of temperature sensors and can also be used to convert heat into electric power....
    s containing alloys of rhenium and tungsten are used to measure temperatures up to 2200 °C
    Celsius

    Celsius is a temperature scale that is named after the Swedish astronomer Anders Celsius , who developed a similar temperature scale two years before his death....
    .
  • Rhenium wire is used in photoflash lamps in photography
    Photography

    Photography is the process, activity and art of creating still or moving by recording radiation on a sensitive medium, such as a photographic film, or an ....
    .
  • Rhenium forms rhenium diboride
    Rhenium diboride

    Rhenium diboride is a synthetic superhard material. It was discovered by a team at University of California, Los Angeles and announced in Science in April 2007....
     with boron
    Boron

    Boron is a chemical element with atomic number 5 and the chemical symbol B. Boron is a trivalent metalloid element which occurs abundantly in the evaporite ores borax and ulexite....
    . It is a compound noted for its extreme hardness.
  • Isotopes of rhenium are radioactive. The 188 isotope, with a half-life of 69 days, has been tested for treatment of liver cancer
    Liver cancer

    Hepatic tumors are tumors or growths on or in the liver . These growths can be benign or malignant . They may be discovered on medical imaging , or may be present in patients as an abdominal mass, hepatomegaly, abdominal pain, jaundice, or some other liver dysfunction....
    . The 188 isotope may be obtained in the form of a generator.
  • Related by periodic trends
    Periodic trends

    In Chemistry, periodic trends are the tendencies of certain elemental characteristics to increase or decrease as one progresses from one corner of the Periodic table of elements....
    , rhenium has a similar chemistry with technetium
    Technetium

    Technetium is the lightest chemical element with no stable isotope. It is a synthetic element with the atomic number 43 and is given the symbol Tc....
    ; work done to label rhenium onto target compounds can often be translated to technetium. This is useful for radiopharmacy, where it is difficult to work with technetium - especially the 99m isotope used in medicine - due to its expense and short half-life.


Precaution

Very little is known about the toxicity of rhenium compounds because they are used in very small amounts, but soluble salts, such as the rhenium halides or perrhenates, could be hazardous due to elements other than rhenium or due to rhenium itself.

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