"Tungsten Tungsten, or wolfram, is a chemical element with symbol W and atomic number 74. The name ""tungsten"" comes from the former Swedish name for the tungstate mineral ""scheelite"", ""tung sten"" or ""heavy stone"". Tungsten is a rare metal found naturally on Earth almost exclusively combined with other elements in chemical compounds rather than alone. It was identified as a new element in 1781 and first isolated as a metal in 1783. Its important ores include wolframite and scheelite. The free element is remarkable for its robustness, especially the fact that it has the highest melting point of all the"
"the name Georg Agricola used for the element in 1546, which translates into English as ""wolf's froth"" and is a reference to the large amounts of tin consumed by the mineral during its extraction. Tungsten is found mainly in the minerals wolframite (iron–manganese tungstate (Fe,Mn)WO, which is a solid solution of the two minerals ferberite FeWO, and hübnerite MnWO) and scheelite (calcium tungstate (CaWO). Other tungsten minerals range in their level of abundance from moderate to very rare, and have almost no economical value. Tungsten forms chemical compounds in oxidation states from -II to VI. Higher oxidation states, always as"
"niobium, occurs in the minerals tantalite, columbite and coltan (a mix of columbite and tantalite). Tungsten, also known as wolfram, is a chemical element with the chemical symbol W and atomic number 74. The word ""tungsten"" comes from the Swedish language ""tung sten"" directly translatable to ""heavy stone"", though the name is ""volfram"" in Swedish to distinguish it from Scheelite, in Swedish alternatively named ""tungsten"". A hard, rare metal under standard conditions when uncombined, tungsten is found naturally on Earth only in chemical compounds. It was identified as a new element in 1781, and first isolated as a metal in"
"German for ""wolf's foam"", how the mineral was known to Saxon miners. The name ""tungsten"" means ""heavy stone"", a description of scheelite, another mineral in which tungsten is found. The German names for hydrogen, oxygen, and nitrogen are ""Wasserstoff"" (water substance), ""Sauerstoff"" (acid substance), and ""Stickstoff"" (smothering substance). Russian names for hydrogen, oxygen and carbon are ""vodorod"", ""kislorod"" and ""uglerod"" (generating water, acid and coal respectively). The corresponding Chinese names are ""qīngqì"" (light gas), ""yǎngqì"" (nourishing gas), and ""dànqì"" (diluting gas). A scheme for translating chemical names into Chinese was developed by John Fryer and Xu Shou in 1871. Where"
"and target), electrodes in gas tungsten arc welding, superalloys, and radiation shielding. Tungsten's hardness and high density give it military applications in penetrating projectiles. Tungsten compounds are also often used as industrial catalysts. Tungsten is the only metal from the third transition series that is known to occur in biomolecules that are found in a few species of bacteria and archaea. It is the heaviest element known to be essential to any living organism. Tungsten interferes with molybdenum and copper metabolism and is somewhat toxic to animal life. In its raw form, tungsten is a hard steel-grey metal that is"
"Tungstate In chemistry, a tungstate is a compound that contains an oxoanion of tungsten or is a mixed oxide containing tungsten. The simplest tungstate ion is , ""orthotungstate"". Many other tungstates belong to a large group of polyatomic ions that are termed polyoxometalates, (""POMs""), and specifically termed isopolyoxometalates as they contain, along with oxygen and maybe hydrogen, only one other element. Almost all useful tungsten ores are tungstates. Orthotungstates feature tetrahedral W(VI) centres with short W–O distances of 1.79 Å. Structurally, they resemble sulfates. Six-coordinate, octahedral tungsten dominates in the polyoxotungstates. In these compounds, the W–O distances are elongated. Some"
"Tungsten trioxide Tungsten(VI) oxide, also known as tungsten trioxide or tungstic anhydride, WO, is a chemical compound containing oxygen and the transition metal tungsten. It is obtained as an intermediate in the recovery of tungsten from its minerals. Tungsten ores are treated with alkalis to produce WO. Further reaction with carbon or hydrogen gas reduces tungsten trioxide to the pure metal. Tungsten(VI) oxide occurs naturally in the form of hydrates, which include minerals: tungstite WO·HO, meymacite WO·2HO and hydrotungstite (of the same composition as meymacite, however sometimes written as HWO). These minerals are rare to very rare secondary tungsten minerals."
"and, during World War I, restrict German access elsewhere. In World War II, tungsten played a more significant role in background political dealings. Portugal, as the main European source of the element, was put under pressure from both sides, because of its deposits of wolframite ore at Panasqueira. Tungsten's desirable properties such as resistance to high temperatures, its hardness and density, and its strengthening of alloys made it an important raw material for the arms industry, both as a constituent of weapons and equipment and employed in production itself, e.g., in tungsten carbide cutting tools for machining steel. The name"
"upon acidification. Tungstate In chemistry, a tungstate is a compound that contains an oxoanion of tungsten or is a mixed oxide containing tungsten. The simplest tungstate ion is , ""orthotungstate"". Many other tungstates belong to a large group of polyatomic ions that are termed polyoxometalates, (""POMs""), and specifically termed isopolyoxometalates as they contain, along with oxygen and maybe hydrogen, only one other element. Almost all useful tungsten ores are tungstates. Orthotungstates feature tetrahedral W(VI) centres with short W–O distances of 1.79 Å. Structurally, they resemble sulfates. Six-coordinate, octahedral tungsten dominates in the polyoxotungstates. In these compounds, the W–O distances are"
"of different chemicals used in the ""Lowry Assay"" for protein content analysis. Its density, similar to that of gold, allows tungsten to be used in jewelry as an alternative to gold or platinum. Metallic tungsten is hypoallergenic, and is harder than gold alloys (though not as hard as tungsten carbide), making it useful for rings that will resist scratching, especially in designs with a brushed finish. Because the density is so similar to that of gold (tungsten is only 0.36% less dense), tungsten can also be used in counterfeiting of gold bars, such as by plating a tungsten bar with"
"Tungsten (music) A Tungsten or Tungs-Tone is a type of phonograph stylus. Constructed from tungsten wire, held in a metal shank, a tungsten stylus differs from a steel stylus in that it has a cylindrical rather than a conical shape, meaning that the cross-section of the stylus remains the same as the stylus wears down improving durability to several plays. Typically, a new steel needle is required for every record played on an old acoustic phonograph. This is because the record contains abrasive material. In the first few silent tracks this abrasion hones the steel needle to a profile that"
"elements discovered, melting at 3422 °C (6192 °F, 3695 K). It also has the highest boiling point, at 5930 °C (10706 °F, 6203 K). Its density is 19.3 times that of water, comparable to that of uranium and gold, and much higher (about 1.7 times) than that of lead. Polycrystalline tungsten is an intrinsically brittle and hard material (under standard conditions, when uncombined), making it difficult to work. However, pure single-crystalline tungsten is more ductile and can be cut with a hard-steel hacksaw. Tungsten's many alloys have numerous applications, including incandescent light bulb filaments, X-ray tubes (as both the filament"
"Tungstic acid Tungstic acid refers to hydrated forms of tungsten trioxide, WO. The simplest form, the monohydrate, is WO·HO, HWO. The dihydrate WO·2HO is also known. The solid-state structure of WO·HO consists of layers of octahedrally coordinated WO(HO) units where 4 vertices are shared. The dihydrate has the same layer structure with the extra HO molecule intercalated between the layers. The monohydrate is a yellow solid and insoluble in water. The classical name for this acid is 'acid of wolfram'. Salts of tungstic acid are tungstates. The acid was discovered by Carl Wilhelm Scheele in 1781. Tungstic acid is obtained"
"and in many other ways. Tungsten can be found in printing inks, x-ray screens, photographic chemicals, in the processing of petroleum products, and flame proofing of textiles. Niobium is nearly always found together with tantalum, and was named after Niobe, the daughter of the mythical Greek king Tantalus for whom tantalum was named. Niobium has many uses, some of which it shares with other refractory metals. It is unique in that it can be worked through annealing to achieve a wide range of strength and elasticity, and is the least dense of the refractory metals. It can also be found"
"Mallory metal Mallory metal is proprietary name for an alloy of tungsten, with other metallic elements added to improve machining. Its primary use is as a balance weight which is added to the crankshaft of an automotive engine, where the existing counterweight is not large enough to compensate for the weight of the reciprocating and rotating components attached to the crankshaft's connecting rod journals. Rather than add to the counterweight by welding or fabrication, holes are drilled in structurally safe positions in the counterweights, and ""slugs"" (cylindrical dowels) of Mallory metal are inserted and fastened securely. The difference in density"
"for an alloy of tungsten, with other metallic elements added to improve machining. Tungsten, usually alloyed with nickel and iron or cobalt to form heavy alloys, is used in kinetic energy penetrators as an alternative to depleted uranium, in applications where uranium's radioactivity is problematic even in depleted form, or where uranium's additional pyrophoric properties are not desired (for example, in ordinary small arms bullets designed to penetrate body armor). Similarly, tungsten alloys have also been used in cannon shells, grenades and missiles, to create supersonic shrapnel. Germany used tungsten during World War II to produce shells for anti-tank gun"
"Copper–tungsten Copper–tungsten (tungsten–copper, CuW, or WCu) is a mixture of copper and tungsten. As copper and tungsten are not mutually soluble, the material is composed of distinct particles of one metal dispersed in a matrix of the other one. The microstructure is therefore rather a metal matrix composite instead of a true alloy. The material combines the properties of both metals, resulting in a material that is heat-resistant, ablation-resistant, highly thermally and electrically conductive, and easy to machine. Parts are made from the CuW composite by pressing the tungsten particles into the desired shape, sintering the compacted part, then infiltrating"
"of tungsten are not related to its refractory properties but simply to its density. For example, it is used in balance weights for planes and helicopters or for heads of golf clubs. In this applications similar dense materials like the more expensive osmium can also be used. The most common use for tungsten is as the compound tungsten carbide in drill bits, machining and cutting tools. The largest reserves of tungsten are in China, with deposits in Korea, Bolivia, Australia, and other countries. It also finds itself serving as a lubricant, antioxidant, in nozzles and bushings, as a protective coating"
"Tungsten carbide Tungsten carbide (chemical formula: WC) is a chemical compound (specifically, a carbide) containing equal parts of tungsten and carbon atoms. In its most basic form, tungsten carbide is a fine gray powder, but it can be pressed and formed into shapes through a process called sintering for use in industrial machinery, cutting tools, abrasives, armor-piercing rounds, other tools and instruments, and jewelry. Tungsten carbide is approximately twice as stiff as steel, with a Young's modulus of approximately 530–700 GPa (77,000 to 102,000 ksi), and is double the density of steel—nearly midway between that of lead and gold. It"
"gold, which has been observed since the 1980s, or taking an existing gold bar, drilling holes, and replacing the removed gold with tungsten rods. The densities are not exactly the same, and other properties of gold and tungsten differ, but gold-plated tungsten will pass superficial tests. Gold-plated tungsten is available commercially from China (the main source of tungsten), both in jewelry and as bars. Because it retains its strength at high temperatures and has a high melting point, elemental tungsten is used in many high-temperature applications, such as light bulb, cathode-ray tube, and vacuum tube filaments, heating elements, and rocket"
"used in ceramic glazes and calcium/magnesium tungstates are used widely in fluorescent lighting. Crystal tungstates are used as scintillation detectors in nuclear physics and nuclear medicine. Other salts that contain tungsten are used in the chemical and tanning industries. Tungsten oxide (WO) is incorporated into selective catalytic reduction (SCR) catalysts found in coal-fired power plants. These catalysts convert nitrogen oxides (NO) to nitrogen (N) and water (HO) using ammonia (NH). The tungsten oxide helps with the physical strength of the catalyst and extends catalyst life. Applications requiring its high density include weights, counterweights, ballast keels for yachts, tail ballast for"
"a higher luster when polished. Sometimes manufacturers or retailers refer to tungsten carbide as a metal, but it is a ceramic. Because of tungsten carbide's hardness, rings made of this material are extremely abrasion resistant, and will hold a burnished finish longer than rings made of metallic tungsten. Tungsten carbide rings are brittle, however, and may crack under a sharp blow. The hardness and density of tungsten are applied in obtaining heavy metal alloys. A good example is high speed steel, which can contain as much as 18% tungsten. Tungsten's high melting point makes tungsten a good material for applications"
"tungsten, meaning ""heavy stone"" in Swedish. In 1754, Scottish chemist Joseph Black isolated carbon dioxide, which he called ""fixed air"". In 1757, Louis Claude Cadet de Gassicourt, while investigating arsenic compounds, creates Cadet's fuming liquid, later discovered to be cacodyl oxide, considered to be the first synthetic organometallic compound. In 1758, Joseph Black formulated the concept of latent heat to explain the thermochemistry of phase changes. In 1766, English chemist Henry Cavendish isolated hydrogen, which he called ""inflammable air"". Cavendish discovered hydrogen as a colorless, odourless gas that burns and can form an explosive mixture with air, and published a"
"often brittle and hard to work. If made very pure, tungsten retains its hardness (which exceeds that of many steels), and becomes malleable enough that it can be worked easily. It is worked by forging, drawing, or extruding. Tungsten objects are also commonly formed by sintering. Of all metals in pure form, tungsten has the highest melting point (3422 °C, 6192 °F), lowest vapor pressure (at temperatures above 1650 °C, 3000 °F), and the highest tensile strength. Although carbon remains solid at higher temperatures than tungsten, carbon sublimes at atmospheric pressure instead of melting, so it has no melting point."
"metatungstate ion exists as a symmetric cluster of twelve tungsten-oxygen octahedra known as the Keggin anion. Many other polyoxometalate anions exist as metastable species. The inclusion of a different atom such as phosphorus in place of the two central hydrogens in metatungstate produces a wide variety of heteropoly acids, such as phosphotungstic acid HPWO. Tungsten trioxide can form intercalation compounds with alkali metals. These are known as ""bronzes""; an example is sodium tungsten bronze. In 1781, Carl Wilhelm Scheele discovered that a new acid, tungstic acid, could be made from scheelite (at the time named tungsten). Scheele and Torbern Bergman"
"Tungsram Tungsram is one of Hungary's largest, oldest, and internationally most prestigious firms, known for light bulbs and electronics. Established in Újpest (today part of Budapest, Hungary) in 1896, it initially produced telephones, wires and switchboards. The name ""Tungsram"" is a portmanteau of ""tungsten"" and ""wolfram"" (the two common names of the metal used for making light bulb filaments). On 13 December 1904, Hungarian Sándor Just and Croatian Franjo Hanaman were granted Hungarian patent no. 34541 for the world's first tungsten filament bulb that lasted longer and produced brighter light than a carbon filament. The co-inventors licensed their patent to"
"distinct new element, named ""molybdenum"" for the mineral in which it was discovered. Peter Jacob Hjelm successfully isolated molybdenum by using carbon and linseed oil in 1781. Regarding tungsten, in 1781 Carl Wilhelm Scheele discovered that a new acid, tungstic acid, could be made from scheelite (at the time named tungsten). Scheele and Torbern Bergman suggested that it might be possible to obtain a new metal by reducing this acid. In 1783, José and Fausto Elhuyar found an acid made from wolframite that was identical to tungstic acid. Later that year, in Spain, the brothers succeeded in isolating tungsten by"
"The following excerpt from a mining geology textbook describes its usage in the particular case of tungsten: ""Tungsten concentrates are usually traded in metric tonne units (originally designating one tonne of ore containing 1% of WO, today used to measure WO quantities in 10 kg units. One metric tonne unit (mtu) of tungsten (VI) contains 7.93 kilograms of tungsten."" (Walter L Pohl, ""Economic Geology: Principles and Practices"", English edition, 2011, p 183.) Note that tungsten is also known as wolfram and has the atomic symbol W. In the case of uranium, the acronym ""MTU"" is sometimes considered to be ""metric"
"National Toxicology Program. Tungsten carbide Tungsten carbide (chemical formula: WC) is a chemical compound (specifically, a carbide) containing equal parts of tungsten and carbon atoms. In its most basic form, tungsten carbide is a fine gray powder, but it can be pressed and formed into shapes through a process called sintering for use in industrial machinery, cutting tools, abrasives, armor-piercing rounds, other tools and instruments, and jewelry. Tungsten carbide is approximately twice as stiff as steel, with a Young's modulus of approximately 530–700 GPa (77,000 to 102,000 ksi), and is double the density of steel—nearly midway between that of lead"
"Tungsten is essential for some archaea. The following tungsten-utilizing enzymes are known: A ""wtp"" system is known to selectively transport tungsten in archaea: Because tungsten is rare and its compounds are generally inert, the effects of tungsten on the environment are limited. It was at first believed to be relatively inert and an only slightly toxic metal, but beginning in the year 2000, the risk presented by tungsten alloys, its dusts and particulates to induce cancer and several other adverse effects in animals as well as humans has been highlighted from in vitro and in vivo experiments. The median lethal"
"with a hard-steel hacksaw. The unalloyed elemental form is used mainly in electrical applications. Tungsten's many alloys have numerous applications, most notably in incandescent light bulb filaments, X-ray tubes (as both the filament and target), electrodes in TIG welding, and superalloys. Tungsten's hardness and high density give it military applications in penetrating projectiles. Tungsten compounds are most often used industrially as catalysts. Tungsten is the only metal from the third transition series that is known to occur in biomolecules, where it is used in a few species of bacteria. It is the heaviest element known to be used by any"
"for fishing lures (tungsten beads allow the fly to sink rapidly). Tungsten has seen use recently in nozzles for 3D printing; the high wear resistance and thermal conductivity of tungsten carbide improves the printing of abrasive filaments. Some cello C strings are wound with tungsten. The extra density gives this string more projection and often cellists will buy just this string and use it with three strings from a different set. Tungsten is used as an absorber on the electron telescope on the Cosmic Ray System of the two Voyager spacecraft. Sodium tungstate is used in Folin-Ciocalteu's reagent, a mixture"
"by the action of strong acids on solutions of alkali metallic tungstates. It may also be prepared from the reaction between hydrogen carbonate and sodium tungstate. It can also be obtained from pure tungsten by reaction with hydrogen peroxide. It is used as a mordant and a dye in textiles. Tungstic acid Tungstic acid refers to hydrated forms of tungsten trioxide, WO. The simplest form, the monohydrate, is WO·HO, HWO. The dihydrate WO·2HO is also known. The solid-state structure of WO·HO consists of layers of octahedrally coordinated WO(HO) units where 4 vertices are shared. The dihydrate has the same layer"