Beryllium is a chemical element with the symbols Be and the atomic number 4. This is a relatively rare element in the universe, usually occurring as a product of the spallation of larger atomic nuclei that has collide with cosmic rays. Inside the beryllium core core will run out because it merges and creates a larger element. This is a divalent element that occurs naturally only in combination with other elements in the mineral. Notable gemstones containing beryllium include beryl (aquamarine, emerald) and chrysoberyl. As the free element is a base metal metal that is gray, strong, light and brittle.
Beryllium increases many physical properties when added as an element of aluminum alloy, copper (especially beryllium copper alloys), iron and nickel. Beryllium does not form oxides until it reaches very high temperatures. Tools made of strong and hard beryllium copper alloys and do not create sparks as they strike the steel surface. In structural applications, the combination of high bending rigidity, thermal stability, low thermal conductivity and density (1.85 times of water) makes beryllium metal the desired aerospace material for aircraft components, missiles, spacecraft, and satellites. Due to its low density and atomic mass, beryllium is relatively transparent to X-rays and other forms of ionizing radiation; therefore, this is the most common window material for X-ray equipment and particle detector components. The high thermal conductivity of beryllium and beryllium oxide has led to its use in thermal management applications.
The commercial use of beryllium requires the use of appropriate dust control equipment and industrial control at all times due to the toxicity of dust containing beryllium inhalation that can cause chronic life-threatening allergic diseases in some people called berylliosis.
Video Beryllium
Characteristics
Physical properties
Beryllium is a brittle and hard steel that is brittle at room temperature and has a very densely packed hexagonal crystalline structure. It has an extraordinary stiffness (Young 287 GPa modulus) and a fairly high melting point. The beryllium elastic modulus is about 50% larger than steel. The combination of this modulus and relatively low density resulted in extremely fast sound conduction velocity in beryllium - about 12.9 km/sec under ambient conditions. Other important properties are high specific heat (1925 JÃ, Â · kg -1 Ã, Â · K -1 ) and thermal conductivity (216 WÃ, Â · m < soup> -1 Ã, Â · K -1 ), which makes beryllium metal with the best heat dissipation characteristics per unit weight. In combination with the relatively low linear thermal expansion coefficient (11,4ÃÆ' â € "10 -6 K -1 ), this characteristic yields unique stability under thermal loading conditions.
Nuclear properties
Natural beryllium, except for mild contamination by cosmogenic radioisotopes, is a pure-isotope beryllium, which has a nuclear spin 3 span>. Beryllium has a large scattering cross section for high-energy neutrons, about 6 barns for energy above about 10 keV. Therefore, it acts as a neutron reflector and a neutron moderator, effectively slowing neutrons into thermal energy ranges below 0.03 eV, in which the total cross section is at least an order of magnitude lower - the exact value depends on purity and size. of crystallites in the material.
Single primordial beryllium isotope 9 Also undergoes a neutron reaction (n, 2n) with a neutron energy of more than 1.9 MeV, yielding 8 Be, which almost immediately breaks into two alpha particles. Thus, for high-energy neutrons, beryllium is a neutron multiplier, releasing more neutrons than they absorb. This nuclear reaction is:
- 9
4
2 He
2 n
Neutron dibebaskan ketika inti berilium dipukul oleh partikel alfa energik yang menghasilkan reaksi nuklir
- 9
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6 C
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adalah partikel alfa dan 12
6 C
adalah inti karbon-12.
Beryllium also releases neutrons under gamma-ray bombing. Thus, the natural beryllium that is bombarded by alpha or gammas from suitable radioisotopes is a key component of most radioactive neutron nuclear reaction sources for the production of free neutrons in the laboratory.
Sejumlah kecil tritium dibebaskan ketika 9
4 Menjadi
nuclei menyerap neutron energi rendah di reaksi nuklir tiga langkah
- 9
4 Jadilah
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6
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, 6
2 Dia
-> 6
< sub gaya = "f ont-size: inherit; line-height: inherit; vertical-align: baseline "> 3 Li
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3 Li
n -> 4
2 Dia
3
1 H
Note that 6
2 He
has a half-life of just 0.8 seconds ,? - is an electron, and 6 > 3 Li
high absorption of neutron cross. Tritium is a radioisotope of concern in the waste stream of nuclear reactors.
As a metal, transparent beryllium for most X-ray wavelengths and gamma rays, making it useful for X-ray tube output windows and other equipment.
Isotopes and nukleosynthesis
Both stable and unstable beryllium isotopes are made in stars, but radioisotopes do not last long. It is believed that most of the stable beryllium in the universe was originally created on interstellar medium when cosmic rays induce fission in heavier elements found in interstellar gas and dust. Primordial beryllium contains only one stable isotope, 9 , and therefore beryllium is a monoisotopic element.
Cosmogenic radioactive 10 Be produced in Earth's atmosphere by cosmic ray spacings of oxygen. 10 Accumulates on the soil surface, where a relatively long half-life (1.36 million years) allows a long stay before decomposing into boron-10. Thus, 10 Be and its daughter products are used to check for natural soil erosion, soil formation and laterite soil development, and as a proxy for measuring variation in solar activity and ice age age. Production of 10 Be inversely proportional to solar activity, as the increase of solar wind during periods of high solar activity reduces the cosmic ray flux of galaxies reaching Earth. The nuclear explosion also forms a 10 Be with a fast neutron reaction with 13 C in carbon dioxide in the air. This is one of the indicators of past activity at nuclear weapons testing sites. The isotope 7 Be (half-day) is also cosmogenic, and shows an abundance of atmospheres associated with sunspots, such as 10 Be.
8 Be has a very short half-life of about 7 ÃÆ' - 10 - 17 that contributes to his significant cosmological role , because elements heavier than beryllium could not have been generated by nuclear fusion in the Big Bang. This is due to the lack of sufficient time during the Big Bang nucleosynthesis phase to produce carbon by the fusion of 4 nuclei and the very low concentrations of available beryllium-8. The English astronomer Sir Fred Hoyle first pointed out that the energy levels of 8 Be and 12 C allow carbon production by the so-called triple-alpha process in helium-fueled stars more time nucleosynthesis is available. This process allows carbon to be produced in stars, but not in the Big Bang. The carbon made by stars (the basis of carbon-based life) is thus a component in the elements in gas and dust released by AGB stars and supernovas (see also Big Bang nucleosynthesis), and the creation of all other elements with more numbers of atoms large from carbon.
The 2s of beryllium electrons can contribute to chemical bonds. Therefore, when 7 decays by capturing L-electrons, it does so by taking electrons from the atomic orbitals that may participate in the bond. This makes its decay rate dependent on the level that can be measured in its chemical environment - a rare occurrence in nuclear decay.
The shortest living beryllium isotope is 13 Be that decays through neutron emissions. It has a half-life of 2.7 ÃÆ' â € "10 -21 . 6 Be also very short-lived with half-life 5.0Ã,ÃÆ' â € "10 -21 . Exotic isotope 11 Be and 14 Be known to show off a nuclear halo. This phenomenon can be understood as the nuklei 11 Be and 14 Have, respectively, 1 and 4 neutrons orbit substantially outside the classical Fermi 'waterdrop' model of the nucleus.
Genesis
The sun has a concentration of 0.1 parts per billion (ppb) of beryllium. Beryllium has a concentration of 2 to 6 parts per million (ppm) in the Earth's crust. Most concentrated on the ground, 6 ppm. Keep track of the number of 9 Be found in Earth's atmosphere. Beryllium concentration in seawater is 0.2-0.6 parts per trillion. However, in river water, beryllium is more abundant with a concentration of 0.1 ppb.
Beryllium is found in more than 100 minerals, but most are rare. The more common beryllium minerals contain: bertrandit (Be 4 Si 2 O 7 (OH) 2 ), beryl (Al 2 Be 3 6 ), chrysoberyl (Al 2 BeO 4 ) and phenakite (Be 2 SiO 4 ). Beryl valuable shapes are aquamarine, red beryl and emerald. The green color in beryl-jeweled form comes from various chromium counts (about 2% for emeralds).
Two major ores of beryllium, beryl and bertrandit, are found in Argentina, Brazil, India, Madagascar, Russia and the United States. Total world beryllium ore reserves of more than 400,000 tons.
Maps Beryllium
Production
Beryllium extraction from its compounds is a difficult process because of its high affinity for oxygen at high temperatures, and its ability to reduce water when the oxide film is removed. The United States, China, and Kazakhstan are the only three countries involved in industrial scale beryllium extraction. Beryllium production technology is in the early stages of development in Russia after a hiatus of 20 years.
Beryllium is most often extracted from beryl minerals, which are sintered using an extraction agent or melted into a soluble mixture. The sintering process involves mixing beryl with sodium fluorosilicate and soda at 770 ° C (1,420 ° F) to form sodium fluoroberyllate, aluminum oxide and silicon dioxide. Beryllium hydroxide is precipitated from aqueous sodium fluoroberyllate and sodium hydroxide solution. Beryllium extraction using the melting method involves grinding beryl into powder and heating it up to 1,650 ° C (3,000 ° F). Rapid melting is cooled with water and then reheated 250 to 300 ° C (482-57.2 ° F) in concentrated sulfuric acid, which mostly produces beryllium sulfate and aluminum sulphate. Watery ammonia is then used to remove aluminum and sulfur, leaving beryllium hydroxide.
Beryllium hydroxide prepared using sinter or melted method is then converted to beryllium fluoride or beryllium chloride. To form fluoride, aqueous ammonium hydrogen fluoride is added to beryllium hydroxide to produce ammonium tetrafluoroberyllate precipitate, which is heated to 1,000 ° C (1,830 ° F) to form beryllium fluoride. Heating of fluoride up to 900 ° C (1,650 ° F) with magnesium forms a finely divided beryllium, and additional heating to 1,300 ° C (2,370 ° F) creates a compact metal. The heating of beryllium hydroxide forms the oxide, which becomes beryllium chloride when combined with carbon and chlorine. Electrolysis of the liquid beryllium chloride was then used to obtain the metal.
Chemical properties
The chemical behavior of Beryllium is largely the result of small atomic and ionic radii. Thus it has a very high ionization potential and strong polarization while bound to other atoms, which is why all its compounds are covalent. This is more chemically similar to aluminum than its adjacent neighbors in the periodic table because it has a similar charge-to-radius ratio. The oxide layer is formed around the beryllium which prevents further reactions with air unless heated above 1000 ° C. Once ignited, beryllium burns brilliantly to form a mixture of beryllium oxide and beryllium nitride. Beryllium is easily soluble in non-oxidizing acids, such as HCl and H 2 SO 4 , but not in nitric acid or water as these form oxides. This behavior is similar to aluminum metal. Beryllium is also soluble in alkaline solution.
The beryllium atom has an electronic configuration of [Dia] 2s 2 . Both valence electrons give the beryllium oxidation state 2 and thus the ability to form two covalent bonds; the only evidence of a lower valence of beryllium is the solubility of metals in BeCl 2 , and in two neutral beryllium bis (carbene) compounds in which Be centers contain a zero formal oxidation state. Due to octet rules, atoms tend to look for valence 8 to resemble noble gases. Beryllium attempts to achieve coordination number 4 because its two covalent bonds fill this half octet. Tetracoordinasi allows beryllium compounds, such as fluoride or chloride, to form polymers.
This characteristic is used in analytical techniques using EDTA as a ligand. Special EDTA forms the octahedral complex - thus absorbing other cations such as Al 3 which may interfere - for example, in the extraction of complex solvents formed between Be 2 and acetylacetone. Beryllium (II) easily forms complexes with strong donor ligands such as phosphine oxide and oxide arsine. There is much research on these complexes that show the stability of the O-Be bond.
Beryllium salt solution, eg. beryllium sulfate and beryllium nitrate, are acidic due to ion hydrolysis [Be (H 2 O) 4 ] 2 .
- [Be (H 2 O) 4 ] 2 H 2 O? [Be (H 2 O) 3 (OH)] H 3 O
Other products of hydrolysis include trimeric ion (OH) 3 (H 2 O) 6 ] < soup> 3 . Beryllium hydroxide, Be (OH) 2 , insoluble even in acidic solutions with a pH less than 6, ie at biological pH. This is amphoteric and soluble in a strong base solution.
Beryllium forms a binary compound with many non-metals. Halide anhydride is known for F, Cl, Br, and I. BeF 2 has a silica-like structure with BeF corner 4 tetrahedra. BeCl 2 and BeBr 2 have a chain structure with joint-edge tetrahedra. All beryllium halides have the molecular structure of a linear monomer in the gas phase.
Beryllium difluoride, BeF 2 , differs from other difluorides. Generally speaking, beryllium has a tendency to bind covalently, much more than other alkaline earths and its fluorides are partially covalent (though still more ionic than other halides). BeF 2 has much in common with SiO 2 (quartz) which is largely covalently binding. BeF 2 has metal and form of coordinated tetrahedrally eyewear (difficult to crystallize). When crystals, beryllium fluoride has the same room temperature crystal structure as quartz and shares many higher temperature structures as well. Beryllium difluoride is very soluble in water, unlike other alkaline earth difluorides. (Although they are highly ionic, they do not dissolve due to the very strong lattice strength of the fluorite structure.) However, BeF 2 has much lower electrical conductivity when in solution or when liquid than expected. if it is fully ionic.
Beryllium oxide, BeO, is a white refractory solid, which has a wurtzite crystal structure and thermal conductivity as high as several metals. BeO is amphoter. Beryllium salts can be produced by treating Be (OH) 2 with acids. Beryllium sulfide, selenide and telluride are known, all of which have a sengblende structure.
Beryllium nitride, Be 3 N 2 is a high melting point compound that is ready to be hydrolyzed. Beryllium azide, known BeN 6 and beryllium phosphide, Be 3 P 2 have a structure similar to Be 3 N 2 . Basic beryllium nitrate and base beryllium acetate have a tetrahedral structure similar to four beryllium atoms that are coordinated into central oxide ions. A number of known beryllium borides, such as Be 5 B, Be 4 B, BeB 2 , BeB 6 and BeB 12 . Beryllium carbide, Be 2 C, is a refractory brick-red compound that reacts with water to produce methane. No beryllium silicides have been identified.
History
Beryl minerals, which contain beryllium, have been used since at least the Egyptian Ptolemaic dynasty. In the first century AD, the Roman naturalist Pliny the Elder mentions in his encyclopedia of Natural History that beryl and emerald ("smaragdus") are similar. Papyrus Graecus Holmiensis, written in the third or fourth century, contains notes on how to prepare emeralds and artificial beryl.
Initial analysis of emeralds and beryls by Martin Heinrich Klaproth, Torbern Olof Bergman, Franz Karl Achard, and Johann Jakob Bindheim always produce the same element, leading to the erroneous conclusion that these two substances are aluminum silicates. Mineralogist RenÃÆ'Â © Just HaÃÆ'¼y found that both crystals were geometrically identical, and he asked chemist Louis-Nicolas Vauquelin for chemical analysis.
In a 1798 paper read out in front of the Institut de France, Vauquelin reported that he discovered a new "earth" by dissolving aluminum hydroxide from emeralds and beryl in extra alkali. The editors of the journal Annales de Chimie et de Physique gave the name "new earth" to the sweetness of some of its compounds. Klaproth prefers the name "beryllina" due to the fact that yttria also form sweet salts. The name "beryllium" was first used by WÃÆ'¶hler in 1828.
Friedrich WÃÆ'¶hler and Antoine Bussy independently isolated beryllium in 1828 by chemical reaction of potassium metal with beryllium chloride, as follows:
- BeCl 2 2 K -> 2 KCl Be
Using an alcohol lamp, WÃÆ'¶hler is heated alternately layers of beryllium chloride and potassium in a platinum covered cabinet container. The above reaction immediately occurs and causes the container to be white hot. After cooling and washing the gray powder he produced, he noticed that it was made of fine particles with a dark metal luster. Highly reactive potassium has been produced by electrolysis of its compounds, a process that was discovered 21 years earlier. The chemical method of using potassium only produces small beryllium seeds with no metal ingots that can be cast or hammered.
The direct electrolysis of the melting mixture of beryllium fluoride and sodium fluoride by Paul Lebeau in 1898 produced the first pure sample (99.5-99.8%) of beryllium. However, industrial production only began after the First World War. Involvement of indigenous industries including subsidiaries and scientists associated with Union Carbide and Carbon Corporation in Cleveland OH and Siemens & amp; Halske AG in Berlin. In the US, the process was ruled by Hugh S. Cooper, director of The Kemet Laboratories Company. In Germany, the first commercial success process for producing beryllium was developed in 1921 by Alfred Stock and Hans Goldschmidt.
The beryllium sample was bombarded with alpha rays from radium decay in a 1932 experiment by James Chadwick that revealed the presence of neutrons. This same method is used in a class of radioisotope-based laboratory neutron sources that produce 30 neutrons for every million? particle.
Beryllium production increased rapidly during World War II, due to increased demand for hard beryllium copper alloys and phosphorus for fluorescent lamps. Most early fluorescent lamps use zinc orthosilicate with diverse beryllium content to emit greenish light. The small addition of magnesium tungstate increases the blue part of the spectrum to produce acceptable white light. Halophosphate-based phosphorus replaces beryllium phosphorus after beryllium is found to be toxic.
Electrolysis of the mixture of beryllium fluoride and sodium fluoride was used to isolate beryllium during the 19th century. The high melting point of the metal makes this process more energy than the process used for alkali metals. At the beginning of the 20th century, beryllium production by thermal decomposition of beryllium iodide was investigated following the success of similar processes for the production of zirconium, but this process proved uneconomical for volume production.
Pure beryllium metal was not available until 1957, although it has been used as a metal alloy to harden and strengthen copper early. Beryllium can be produced by reducing beryllium compounds such as beryllium chloride with potassium or metallic sodium. Currently, part of beryllium is produced by reducing beryllium fluoride with a purified magnesium. Prices in the American market for vacuum beryllium ingots were about $ 338 per pound ($ 745 per kilogram) in 2001.
Between 1998 and 2008, world production of beryllium decreased from 343 to about 200 tons, of which 176 tons (88%) were from the United States.
Etymology
The earliest precursors of the berylium can be traced to many languages, including Latin beryllus ; French bÃÆ' Â © ry ; Ancient Greek ???????? , b? rullos , 'beryl'; Prakrit ???????? ( veruliya ); P? Li ??????? ( ve? uriya ), ?????? ( ve? iru ) or ????? ( vi> ar ) - "to pale", referring to semiprecious beryl gemstones pale. The original source might be the Sanskrit word ??????? ( vaidurya ), originating from South India and can be linked to the modern Belur city name. For about 160 years, beryllium is also known as glucinium or glucinium (with an accompanying chemical symbol " Gl ", or" G "), a name derived from the Ancient Greek word for sweet: ?????? , due to the sweetness of the beryllium salt.
Apps
Radiation window
Because of the low number of atoms and the very low absorption of X-rays, the oldest and still one of the most important applications of beryllium is in the radiation window for the X-ray tube. Extreme demands are placed on the purity and hygiene of beryllium to avoid artifacts in X-ray images. Thin beryllium foils are used as radiation windows for X-ray detectors, and very low absorption minimizes the heating effect caused by high intensity, low energy X-rays typical of synchrotron radiation. Strict vacuum windows and tubes for radiation experiments on synchrotrons are produced exclusively from beryllium. In scientific settings for various studies of X-ray emissions (eg, energy-dispersive X-ray spectroscopy) the sample holders are usually made of beryllium because emitted X-rays have lower energy (~ 100Ã, eV) than most X-rays learn the material.
A low number of atoms also makes beryllium relatively transparent to energetic particles. Therefore, it is used to build light pipe around the collision area in the particle physics setting, such as the four major detector experiments in the Large Hadron Collider (ALICE, ATLAS, CMS, LHCb), Tevatron and SLAC. The low density of beryllium allows the collision product to reach the surrounding detector without significant interaction, its rigidity enabling strong vacuum to be produced in the pipeline to minimize interaction with the gas, thermal stability enables it to function properly at temperatures of only a few degrees. above absolute zero, and its diamagnetic properties keep it away from interference with the complex multipole magnetic system used to direct and focus the particle beam.
Mechanical apps
Due to its rigidity, its light weight and dimensional stability over a wide temperature range, beryllium metal is used for lightweight structural components in defense and aerospace industry in high-speed aircraft, missiles, spacecraft and satellites. Some liquid fuel rockets have been using rocket nozzles made of pure beryllium. The beryllium powder itself is studied as a rocket fuel, but this use never materializes. A small number of extreme high-end bike frames have been built with beryllium. From 1998 to 2000, the McLaren Formula One team used a Mercedes-Benz engine with an aluminum-alloy beryllium piston. The use of beryllium engine components is prohibited after protests by Scuderia Ferrari.
Mixing about 2.0% of beryllium into copper forms an alloy called beryllium copper which is six times stronger than copper alone. Beryllium alloys are used in many applications because of their combination of elasticity, high electrical conductivity and thermal conductivity, high strength and hardness, nonmagnetic properties, as well as good corrosion and fatigue resistance. These applications include non-spark devices used near flammable gases (beryllium nickel), in springs and membranes (beryllium nickel and beryllium iron) used in surgical instruments and high temperature devices. At least 50 parts per million of beryllium mixed with liquid magnesium leads to a significant increase in oxidation resistance and a decrease in flammability.
Elastic high beryllium stiffness has led to its extensive use in precision instrumentation, for example in inertial guidance systems and in support mechanisms for optical systems. The copper-beryllium alloy is also applied as a hardening agent in the "Jason gun", which is used to peel paint from the hull of a ship.
Beryllium is also used for cantilevers in styrofoam styles with high performance, where extreme stiffness and low density allow to track weight to be reduced to 1 gram, while still tracking high frequency paths with minimal distortion.
The main prior beryllium applications are the brakes for military aircraft due to their hardness, high melting point, and the extraordinary ability to dissipate heat. Environmental considerations have caused substitution by other materials.
To reduce costs, beryllium can be mixed with large quantities of aluminum, producing AlBeMet alloys (trade names). This mixture is cheaper than pure beryllium, while still retaining many of the desired properties.
Mirrors
The beryllium mirror is very interesting. Large mirrors, often with honeycomb support structures, are used, for example, in meteorological satellites where low weight and long-term dimensional stability are essential. Smaller beryllium mirrors are used in optical guidance systems and fire control systems, eg. in Leopard 1's main battle tanks and German-made Leopard 2. In this system, it takes a very fast mirror movement that once again dictates the low mass and high stiffness. Usually a beryllium mirror is coated with a hard electroless nickel coating that can be more easily polished to complete optics better than beryllium. In some applications, though, blank beryllium is polished without layers. This is especially true for cryogenic operations where a mismatch of thermal expansion can cause a layer to buckle.
The James Webb Space Telescope will have 18 parts of beryllium hexagonal for its mirror. Because JWST will face a temperature of 33 K, a mirror made of gold-plated beryllium, capable of handling extreme cold is better than glass. Beryllium contracts and damages less than glass - and remains more uniform - in such temperatures. For the same reason, Spitzer Space Telescope optics is entirely made of beryllium metal.
Magnetic application
Beryllium is not magnetic. Therefore, tools made from beryllium-based materials are used by naval or army explosive weapons smuggling teams to work in or near the naval mines, since these mines generally have a magnetic effect. They are also found in maintenance and construction materials near the magnetic resonance imaging machine (MRI) due to the high magnetic field generated. In the field of strong radio and radar communications (usually military), hand tools made of beryllium are used to tune the highly magnetic klystrons, magnetrons, current wave tubes, etc., which are used to produce high-level microwave power in the transmitter.
Nuclear applications
Thin plates or beryllium foils are sometimes used in the design of nuclear weapons as the outermost layer of the plutonium pit at the main stage of the thermonuclear bomb, placed to surround the fissile material. This beryllium layer is a good "booster" for plutonium-239 explosions, and they are good neutron reflectors, just like in beryllium nuclear reactors.
Beryllium is also commonly used in some neutron sources in laboratory devices where relatively few neutrons are needed (rather than having to use nuclear reactors, or particle-powered neutron generators). For this purpose, the target of beryllium-9 is bombarded with energetic alpha particles from radioisotopes such as polonium-210, radium-226, plutonium-238, or americium-241. In the nuclear reaction, the beryllium nucleus is converted to carbon-12, and one free neutron is emitted, moving in the same direction as the alpha particle. The alpha beryllium neutron source, called the "urchin" neutron initiator, was used in some early atomic bombs. The sources of neutrons in which beryllium is bombarded with gamma rays from gamma decay radioisotopes, are also used to produce laboratory neutrons.
Beryllium is also used in fuel fabrication for CANDU reactors. The fuel elements have a small complement of brazing resistance to the fuel cladding using induction brazing process with Be as a braze filler. Bearing pads are brazed in place to prevent fuel bundles for pressure-tube contact, and spacer pads between brazed elements to prevent elements to the contact element.
Beryllium is also used in the Torus fusion nuclear research laboratory with Europe, and will be used in more sophisticated ITER to condition the components that face the plasma. Beryllium has also been proposed as a cladding material for nuclear fuel rods, due to a good combination of mechanical, chemical, and nuclear properties. Beryllium fluoride is one of the salts that composes a salt eutectic salt FLiBe, which is used as a solvent, moderator and coolant in many hypothetical liquid salt reactor designs, including liquid thorium fluoride reactors (LFTR).
Acoustics
The low weight and high stiffness of beryllium make it useful as an ingredient for high frequency speaker drivers. Because expensive beryllium (many times more than titanium), difficult to shape due to its fragility, and toxic if mismanaged, beryllium tweeter is limited to home applications, pro audio, and high-end public addresses. Some products with high fidelity have been fraudulently claimed to be made of such material.
Some high-end phonograph cartridges use beryllium cantilevers to improve tracking by reducing mass.
Electronics
Beryllium is a p-type of dopant in a III-V compound semiconductor. It is widely used in materials such as GaAs, AlGaAs, InGaAs and InAlAs grown by molecular beam epitaxy (MBE). The cross-rolled beryllium sheet is an excellent structural support for printed circuit boards in surface-mount technology. In critical electronic applications, beryllium is a structural support and heat sink. The application also requires a coefficient of thermal expansion suitable with alumina and glass-polymide substrates. "E-Materials" beryllium-oxide has been specially designed for this electronic application and has the added advantage that the thermal expansion coefficient can be adjusted to match the diverse substrate materials.
Beryllium oxide is useful for many applications requiring the combined properties of excellent electrical and heat conductor insulators, with high strength and hardness, and very high melting point. Beryllium oxide is often used as an insulator base plate in high power transistors in radio frequency transmitters for telecommunications. Beryllium oxide is also being studied for use in improving the thermal conductivity of uranium dioxide nuclear fuel pellets. Beryllium compounds are used in fluorescent lamp tubes, but this use is discontinued due to the berylliotic disease that develops in the worker who makes the tube.
Health Care
Beryllium is a component of several dental alloys.
Occupational safety and health
Beryllium is a health and safety issue for workers. Beryllium exposure in the workplace can cause a sensitizing immune response and may over time develop chronic beryllium disease (CBD). The National Institute for Occupational Safety and Health (NIOSH) in the United States examines this effect in collaboration with major producers of beryllium products. The purpose of this study was to prevent sensitization and CBD by developing a better understanding of work processes and exposures that could pose a potential risk to workers, and to develop effective interventions that would reduce the risk of adverse health effects. NIOSH also conducts genetic research on sensitization and CBD, regardless of this collaboration. The NIOSH Manual Analysis Method contains methods for measuring the occupational exposure to beryllium.
Precautions
About 35 micrograms of beryllium are found in the average human body, an amount not considered harmful. Beryllium is chemically similar to magnesium and can therefore replace it from enzymes, which causes them to malfunction. Since Be 2 is a high and small charged ion, it can easily enter many tissues and cells, where it specifically targets cell nuclei, inhibits many enzymes, including those used to synthesize DNA. Its toxicity is exacerbated by the fact that the body has no means to control the level of beryllium, and once inside the beryllium can not be removed. Chronic berylosis is a systemic and pulmonary granulomatous disease caused by inhalation of dust or smoke contaminated with beryllium; either in large quantities in a short time or in small amounts in a long time can cause this disease. The symptoms of this disease can take up to five years to develop; about a third of patients with it died and survivors were left disabled. The International Agency for Research on Cancer (IARC) lists beryllium and beryllium compounds as Category 1 carcinogen. In the US, Occupational Safety and Health (OSHA) has set permitted exposure limits (PEL) in the workplace with time-weighted averages (TWA) 0.002 mg/m 3 and constant exposure limits 0.005 mg/m 3 for 30 minutes, with maximum maximum limit of 0.025 mg/m 3 . The National Institute for Occupational Safety and Health (NIOSH) has set a recommended exposure limit (REL) of constant 0.0005 mg/m 3 . The IDLH value (directly harmful to life and health) is 4 mg/m 3 .
The toxicity of the finely divided beryllium (dust or powder, particularly found in industrial settings where beryllium is produced or machined) is well documented. The solid beryllium metal does not carry the same dangers as airborne dust, but the dangers associated with physical contact are not well documented. Workers who deal with beryllium cuttings are therefore routinely advised to handle them with gloves, both as a precaution and because many if not most beryllium applications can not tolerate skin contact residues such as fingerprints.
Acute berylium disease in the form of chemical pneumonitis was first reported in Europe in 1933 and in the United States in 1943. A survey found that about 5% of workers in factories producing fluorescent lamps in 1949 in the United States had associated lung disease with beryllium.. Chronic berylosis resembles sarcoidosis in many ways, and differential diagnosis is often difficult. It kills some early workers in the design of nuclear weapons, such as Herbert L. Anderson.
Beryllium can be found in coal slag. When slag is formulated into an abrasive material for paint blasting and rust from hard surfaces, beryllium can become airborne and become a source of exposure.
Early researchers felt the beryllium and various compounds for sweetness to verify its existence. Modern diagnostic tools no longer require this very risky procedure and no effort should be made to ingest this highly toxic substance. Beryllium and its compounds should be handled with care and special precautions should be taken when performing any activity that may lead to beryllium dust release (lung cancer is a possible outcome from prolonged exposure to beryllium-liquefied dust). Although the use of beryllium compounds in fluorescent lamp tubes was discontinued in 1949, the potential for beryllium exposure exists in the nuclear and aerospace industries and in purification of beryllium metals and melting of alloys containing beryllium, the manufacture of electronic devices, and the handling of other beryllium-containing materials.
Successful tests for air and surface beryllium have been developed and published as the international voluntary consensus standard ASTM D7202. This procedure uses dilute ammonium bifluoride for fluorescence fluorescence and detection with beryllium-bound with sulfonated hydroxybenzoquinoline, enabling detection up to 100 times more sensitive than the recommended limit for beryllium concentrations in the workplace. Fluorescence increases with increasing beryllium concentrations. New procedures have been successfully tested on a variety of surfaces and are effective for ultratrace dissolution and detection of beryllium beryllium and siliceous beryllium refractories (ASTM D7458).
Note
References
- Emsley, John (2001). Natural Building Block: A-Z Guide for Elements . Oxford, UK, UK: Oxford University Press. ISBN: 0-19-850340-7. Ã,
- Mackay, Kenneth Malcolm; Mackay, Rosemary Ann; Henderson, W. (2002). Introduction to modern inorganic chemistry (6th ed.). Press CRC. ISBN 0-7487-6420-8.
- Sunday, Mary Elvira; Leichester, Henry M. (1968). Invention of the Elements . Easton, PA: Journal of Chemistry Education. LCCCN 68-15217.
Further reading
- Newman LS (2003). "Beryllium". Chemistry & amp; Technical News . 36 (36): 38. doi: 10.1021/cen-v081n036.p038.
- Mroz MM, Balkissoon R, Newman LS. "Beryllium". In: Bingham E, Cohrssen B, Powell C (eds.) Patty Toxicology , Fifth Edition. New York: John Wiley & amp; Children 2001, 177-220.
- Walsh, KA, Beryllium Chemical and Processing . Vidal, EE. et al. Eds. 2009, Material Park, OH: ASM International.
- Beryllium Lymphocyte Proliferation Test (BELPT). DOE Description 1142-2001. Washington, DC: US ​​Department of Energy, 2001.
External links
- Case Study of ATSDR in Environmental Medicine: Beryllium Poisoning Department of Health and Human Services USA
- This is Elemental - Beryllium
- MSDS: ESPI Metals
- Beryllium on Periodic Video Table (University of Nottingham)
- National Institute for Occupational Health and Safety - Beryllium Page
- the National Ridge Screening Program (Oak Ridge Associated Universities)
- Beryllium Historic Prices in the US
Source of the article : Wikipedia
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