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Soda Can

Soda can

The aluminum can or aluminium can is a popular beverage can made of aluminum, originally introduced by the Coors Brewing Company. Modern cans are generally produced through a mechanical process that involves punching a flat blank. The malleable metal deforms into the shape of an open-top can, and the top portion of the cylinder may again be deformed in a conical shape. Jagged edges at the top are trimmed, and the container is filled with liquid. Finally, a top piece is affixed to the top of the can, containing a scored region and a pull tab that can be leveraged to open the hole (by pushing the scored region into the can). Early beverage cans were opened by pulling a tab that completely removed a portion of the can's lid. These tabs were a common form of litter—and a lingering hazard for bare feet, especially at public beaches—for many years until a new type of can was introduced. Before 1974, one ripped off a metal tab and tossed it away. The idea of stay-on-tab seems such a simple thing, but it isn’t simple at all. It took a tool engineer from Reynolds Metals, Dan Cudzik, who lives in Richmond Virginia, 5 years to perfect it, while others had given up on trying to make a stay-on-tab purely out of a metal, they felt plastic had to be added. The stay-on-tab has had a huge impact on the environment. If you took all the tabs that have stayed on from 1970 to today - tabs that would be on the ground - they would amount to a couple of trillions. Because they are made of aluminum, these containers are very suitable for recycling. In many parts of the world a deposit can be recovered by turning in empty plastic, glass, and aluminum containers. Unlike glass and plastic, aluminum cans are often purchased in bulk by scrap metal dealers, even when deposits are not offered. Their metal construction also conducts heat more readily than glass or plastic, and drinks in aluminum cans can be chilled more quickly than those in other containers. Many consumers find the taste of a beverage from a can to be different from fountain drinks and beverages from plastic or glass bottles. Additionally, some people believe that aluminum leaching into the fluid contained inside can be dangerous to the drinker's health. The first soft drinks to be sold in all-aluminum cans were R.C. Cola and Diet-Rite Cola (both made by the Royal Crown Cola company), in 1964. A single empty 12 fluid ounce aluminum can weighs approximately 14.5 grams, or 0.51 ounce. Therefore there are about 31 empty aluminum cans to an avoirdupois pound. One problem with the current design is that the top edge of the can may collect dust or dirt in transit, if the can is not packaged in a completely sealed box. As illustrated here, some beverage makers have experimented with putting a separate foil lid on can tops as one solution.

Aluminum

x Aluminium or aluminum (Symbol Al) (see the spelling section below) is a silvery and ductile member of the poor metal group of chemical elements. Its atomic number is 13. Aluminium is found primarily as the ore bauxite and is remarkable for its resistance to oxidation (due to the phenomenon of passivation), its strength, and its light weight. Aluminium is used in many industries to make millions of different products and is very important to the world economy. Structural components made from aluminium are vital to the aerospace industry and very important in other areas of transportation and building in which light weight, durability, and strength are needed.

Properties

transport Aluminium is a soft and lightweight metal with a dull silvery appearance, due to a thin layer of oxidation that forms quickly when it is exposed to air. Aluminium is nontoxic (as the metal) nonmagnetic and non-sparking. Pure aluminium has a tensile strength of about 49 megapascals (MPa) and 700 MPa if it is formed into an alloy. Aluminium is about one-third as dense as steel or copper; is malleable, ductile, and easily machined and cast; and has excellent corrosion resistance and durability due to the protective oxide layer. It is also nonmagnetic and nonsparking and is the second most malleable metal (after gold) and the sixth most ductile. ductile

Applications

Whether measured in terms of quantity or value, the use of aluminium exceeds that of any other metal except iron, and it is important in virtually all segments of the world economy. Pure aluminium has a low tensile strength, but readily forms alloys with many elements such as copper, zinc, magnesium, manganese and silicon. When combined with thermo-mechanical processing these aluminium alloys display a marked improvement in mechanical properties. Aluminium alloys form vital components of aircraft and rockets as a result of their high strength to weight ratio. When aluminium is evaporated in a vacuum it forms a coating that reflects both visible light and radiant heat. These coatings form a thin layer of protective aluminium oxide that does not deteriorate as silver coatings do. In particular, nearly all modern mirrors are made using a thin reflective coating of aluminium on the back surface of a sheet of float glass. Telescope mirrors are also coated with a thin layer of aluminium, but are front coated to avoid internal reflections even though this makes the surface more susceptible to damage. Telescope Diet Coke.]] Some of the many uses for aluminium are in:
- Transportation (automobiles, airplanes, trucks, railroad cars, marine vessels, etc.)
- Packaging (cans, foil, etc.)
- Water treatment
- Construction (windows, doors, siding, building wire, etc.
- Consumer durable goods (appliances, cooking utensils, etc.)
- Electrical transmission lines (aluminium conductors are half the weight of copper for equal conductivity and lower in price[http://www.metalprices.com])
- Machinery.
- Although non-magnetic itself, aluminium is used in MKM steel and Alnico magnets.
- Super purity aluminium (SPA, 99.980% to 99.999% Al) is used in electronics and CDs.
- Powdered aluminium is commonly used for silvering in paint. Aluminium flakes may also be included in undercoat paints, particularly wood primer — on drying, the flakes overlap to produce a water resistant barrier.
- Anodised aluminium is more stable to further oxidation, and is used in various fields of construction.
- Most modern computer CPU heat sinks are made of aluminium due to its ease of manufacture and good heat conductivity. Copper heat sinks are smaller although more expensive and harder to manufacture. Aluminium oxide, alumina, is found naturally as corundum (rubies and sapphires), emery, and is used in glass making. Synthetic ruby and sapphire are used in lasers for the production of coherent light. Aluminium oxidises very energetically and as a result has found use in solid rocket fuels, thermite, and other pyrotechnic compositions. Aluminium is also a superconductor, with a superconduting critical temperature of 1.2 Kelvin.

Engineering use

Improper use of aluminium can result in problems, particularly in contrast to iron or steel, which appear "better behaved" to the intuitive designer, mechanic, or technician. The reduction by two thirds of the weight of an aluminium part compared to a similarly sized iron or steel part seems enormously attractive, but it should be noted that it is accompanied by a reduction by two thirds in the stiffness of the part. Therefore, although direct replacement of an iron or steel part with a duplicate made from aluminium may still give acceptable strength to withstand peak loads, the increased flexibility will cause three times more deflection in the part. Where failure is not an issue but excessive flex is undesirable due to requirements for precision of location or efficiency of transmission of power, simple replacement of steel tubing with similarly sized aluminium tubing will result in a degree of flex which is undesirable; for instance, the increased flex under operating loads caused by replacing steel bicycle frame tubing with aluminium tubing of identical dimensions will cause misalignment of the power-train as well as absorbing the operating force. To increase the rigidity by increasing the thickness of the walls of the tubing increases the weight proportionately, so that the advantages of lighter weight are lost as the rigidity is restored. Aluminium can best be used by redesigning the part to suit its characteristics; for instance making a bicycle of aluminium tubing which has an oversize diameter rather than thicker walls. In this way, rigidity can be restored or even enhanced without increasing weight. The limit to this process is the increase in susceptibility to what is termed "crippling" failure, where the deviation of the force from any direction other than directly along the axis of the tubing causes folding of the walls of the tubing. For instance, a common aluminium soft drink can should be able to support an enormous weight directly along its axis; in practice, however, the walls of the can buckle, crumple, and/or fold up under even a mild force, due to minute deviations from the precise axial direction, making possible the common pastime of flattening an empty can by slamming it against one's forehead. The latest models of the Corvette automobile, among others, are a good example of redesigning parts to make best use of aluminium's advantages. The aluminium chassis members and suspension parts of these cars have large overall dimensions for stiffness but are lightened by reducing cross-sectional area and removing unneeded metal; as a result, they are not only equally or more durable and stiff as the usual steel parts, but they possess an airy gracefulness which most people find attractive. Similarly, aluminium bicycle frames can be optimally designed so as to provide rigidity where required, yet have flexibility in terms of absorbing the shock of bumps from the road and not transmitting them to the rider. The strength and durability of aluminium varies widely, not only as a result of the components of the specific alloy, but also as a result of the particular manufacturing process; for this reason, it has from time to time gained a bad reputation. For instance, a high frequency of failure in many early aluminium bicycle frames in the 1970s resulted in just such a poor reputation; with a moment's reflection, however, the widespread use of aluminium components in the aerospace and automotive high performance industries, where huge stresses are undergone with vanishingly small failure rates, proves that properly built aluminium bicycle components should not be unusually unreliable, and this has subsequently proved to be the case. Similarly, use of aluminium in automotive applications, particularly in engine parts which must survive in difficult conditions, has benefited from development over time. An Audi engineer commented about the V12 engine, producing over 500 horsepower (370 kW), of an Auto Union race car of the 1930s which was recently restored by the Audi factory, that the aluminium alloy of which the engine was constructed would today be used only for lawn furniture and the like. Even the aluminium cylinder heads and crankcase of the Corvair, built as recently as the 1960s, earned a reputation for failure and stripping of threads in holes, even as large as spark plug holes, which is not seen in current aluminium cylinder heads. Often, aluminium's sensitivity to heat must also be considered. Even a relatively routine procedure such as welding is complicated by the fact that aluminium will melt long before it gets even dully red hot; therefore, unlike steel or iron, where the experienced welder can know from its hue how close the metal is to the melting point, welding aluminium requires a degree of expertise incorporating an almost intuitive sense of the metal's temperature, or else the part suddenly and without warning melts into a puddle. Aluminium also will accumulate internal stresses and strains under conditions of overheating; while not immediately obvious, the tendency of the metal to "creep" under sustained stresses results in delayed distortions, for instance the commonly observed warping or cracking of aluminium automobile cylinder heads after an engine is overheated, sometimes as long as years later, or the tendency of welded aluminium bicycle frames to gradually twist out of alignment from the stresses accumulated during the welding process. For this reason, many uses of aluminium in the aerospace industry avoid heat altogether by joining parts using adhesives; this was also used for some of the early aluminium bicycle frames in the 1970s, with unfortunate results when the aluminium tubing corroded slightly, loosening the bond of the adhesive and leading to failure of the frame. Stresses from overheating aluminium can be relieved by heat-treating the parts in an oven and gradually cooling, in effect annealing the stresses; this can also result, however, in the part becoming distorted as a result of these stresses, so that such heat-treating of welded bicycle frames, for instance, results in a significant fraction becoming misaligned. If the misalignment is not too severe, once cooled they can be bent back into alignment with no negative consequences; of course, if the frame is properly designed for rigidity (see above), this will require enormous force.

Household wiring

Because of its high conductivity and relatively low price compared to copper at the time, aluminium was introduced for household electrical wiring to a large degree in the United States in the 1960s. Unfortunately, many of the wiring fixtures at the time were not designed to accept aluminium wire. More specifically:
- The greater coefficient of thermal expansion of aluminium, causes the wire to expand and contract relative to the dissimilar metal screw connection, eventually loosening the connection.
- Pure aluminium has a tendency to "creep" under steady sustained pressure (to a greater degree as the temperature rises), again producing a degree of looseness in an initially tight connection.
- Galvanic corrosion from the dissimilar metals increases the electrical resistance of the connection. In combination, these properties caused connections between electrical fixtures and aluminium wiring to overheat which resulted in several fires. As a result, aluminium household wiring has become unpopular, and in many jurisdictions is not permitted in very small sizes in new construction. However, aluminium wiring can be safely used with fixtures whose connections are designed to avoid loosening and overheating. Older fixtures of this type are marked "Al/Cu", and newer ones are marked "CO/ALR". Otherwise, aluminium wiring can be terminated by crimping it to a short "pigtail" of copper wire, which can be treated as any other copper wire. A properly done crimp, requiring high pressure produced by the proper tool, is tight enough not only to eliminate any thermal expansion of the aluminium, but also to exclude any atmospheric oxygen and thus prevent corrosion between dissimilar metals. New alloys are used for aluminium building wire today in combination with aluminium terminations. Connections made with these standard industry products are as safe and reliable as copper connections. :See also:Aluminum wire

History

The oldest suspected (although unprovable) reference to aluminium is in Pliny the Elder's Naturalis Historia: One day a goldsmith in Rome was allowed to show the Emperor Tiberius a dinner plate of a new metal. The plate was very light, and almost as bright as silver. The goldsmith told the Emperor that he had produced the metal from ordinary clay. He also assured the Emperor that only he, himself, and the gods knew how to produce this metal from clay. The Emperor became very interested, and, as a financial expert, he was also worried. He feared that all his treasures of gold and silver would fall in value if people started producing this bright metal from clay. Therefore, instead of giving the goldsmith the recognition the latter had anticipated, he ordered him to be beheaded. [http://www.findarticles.com/p/articles/mi_m2843/is_n3_v19/ai_16836663 Notes] - [http://www.world-aluminium.org/history/antiquity.html Source] The ancient Greeks and Romans used salts of this metal as dyeing mordants and as astringents for dressing wounds, and alum is still used as a styptic. Further Joseph Needham suggested finds in 1974 showed the ancient Chinese used aluminium (see the link for "Notes" above). In 1761 Guyton de Morveau suggested calling the base alum 'alumine'. In 1808, Humphry Davy identified the existence of a metal base of alum, which he named (see Spelling below for more information on the name). Friedrich Wöhler is generally credited with isolating aluminium (Latin alumen, alum) in 1827 by mixing anhydrous aluminium chloride with potassium. However, the metal had been produced for the first time two years earlier in an impure form by the Danish physicist and chemist Hans Christian Ørsted. Therefore almanacs and chemistry sites often list Øersted as the discoverer of aluminium.[http://www.chemicalelements.com/elements/al.html#isotopes Source] Still it would further be P. Berthier who discovered aluminium in bauxite ore and successfully extracted it. The Frenchman Henri Saint-Claire Deville improved Wöhler's method in 1846 and described his improvements in a book in 1859, chief among these being the substitution of sodium for the considerably more expensive potassium. The American Charles Martin Hall of Oberlin, OH applied for a patent (400655) in 1886 for an electrolytic process to extract aluminium using the same technique that was independently being developed by the Frenchman Paul Héroult in Europe. The invention of the Hall-Héroult process in 1886 made extracting aluminium from minerals cheaper, and is now the principal method in common use throughout the world. Upon approval of his patent in 1889, Hall, with the financial backing of Alfred E. Hunt of Pittsburgh, PA, started the Pittsburgh Reduction Company, renamed to Aluminum Company of America in 1907, later shortened to Alcoa. Alcoa Aluminium was selected as the material to be used for the apex of the Washington Monument, at a time when one ounce cost twice the daily wages of a common worker in the project. [http://www.tms.org/pubs/journals/JOM/9511/Binczewski-9511.html Source] Germany became the world leader in aluminium production soon after Adolf Hitler seized power. By 1942, however, new hydroelectric power projects such as the Grand Coulee Dam gave the United States something Nazi Germany could not hope to compete with, namely the capability of producing enough aluminium to manufacture sixty thousand warplanes in four years. [http://www.phpsolvent.com/wordpress/?page_id=341]

Natural occurrence

Although aluminium is an abundant element in Earth's crust (believed to be 7.5% to 8.1%), it is very rare in its free form and was once considered a precious metal more valuable than gold. Napoleon III of France had a set of aluminium plates reserved for his finest guests. Others had to make do with gold ones. Aluminium has been produced in commercial quantities for just over 100 years. Aluminium was, when it was first discovered, extremely difficult to separate from its ore. Aluminium is among the most difficult metals on earth to refine, despite the fact that it is one of the planet's most common. The reason is that aluminium is oxidised very rapidly and that its oxide is an extremely stable compound that, unlike rust on iron, does not flake off. The very reason for which aluminium is used in many applications is why it is so hard to produce. Recovery of this metal from scrap (via recycling) has become an important component of the aluminium industry. Recycling involves simply melting the metal, which is far less expensive than creating it from ore. Refining aluminium requires enormous amounts of electricity; recycling it requires only 5% of the energy to produce it. A common practice since the early 1900s, aluminium recycling is not new. It was, however, a low-profile activity until the late 1960s when the exploding popularity of aluminium beverage cans finally placed recycling into the public consciousness. Other sources for recycled aluminium include automobile parts, windows and doors, appliances, containers and other products. Aluminium is a reactive metal and it is hard to extract it from its ore, aluminium oxide (Al₂O₃). Direct reduction, with carbon for example, is not economically viable since aluminium oxide has a melting point of about 2000°C. Therefore, it is extracted by electrolysis — the aluminium oxide is dissolved in molten cryolite and then reduced to the pure metal. By this process, the actual operational temperature of the reduction cells is around 950 to 980°C. Cryolite was originally found as a mineral on Greenland, but has been replaced by a synthetic cryolite. Cryolite is a mixture of aluminium, sodium, and calcium fluorides: (Na₃AlF₆). The aluminium oxide (a white powder) is obtained by refining bauxite, which is red since it contains 30 to 40% iron oxide. This is done using the so-called Bayer process. Previously, the Deville process was the predominant refining technology. The electolytic process replaced the Wöhler process, which involved the reduction of anhydrous aluminium chloride with potassium. Both of the electrodes used in the electrolysis of aluminium oxide are carbon. Once the ore is in the molten state, its ions are free to move around. The reaction at the negative cathode is :Al³⁺ + 3e^- → Al Here the aluminium ion is being reduced (electrons are added). The aluminium metal then sinks to the bottom and is tapped off. At the positive electrode (anode) oxygen gas is formed: :2O^2- → O₂ + 4e^- This carbon anode is then oxidised by the oxygen. The anodes in a reduction must therefore be replaced regularly, since they are consumed in the process: :O₂ + C → CO₂ Contrary to the anodes, the cathodes are not consumed during the operation, since there is no oxygen present at the cathode. The carbon cathode is protected by the liquid aluminium inside the cells. Cathodes do erode, mainly due to electrochemical processes. After 5 to 10 years, depending on the current used in the electrolysis, a cell has to be reconstructed completely, because the cathodes are completely worn. Aluminium electrolysis with the Hall-Héroult process consumes a lot of energy, but alternative processes were always found to be less viable economically and/or ecologically. The world-wide average specific energy consumption is approximately 15±0.5 kilowatt-hours per kilogram of aluminium produced (52 to 56 MJ/kg). The most modern smelters reach approximately 12.8 kW·h/kg (46.1 MJ/kg). Reduction line current for older technologies are typically 100 to 200 kA. State-of-the-art smelters operate with about 350 kA. Trials have been reported with 500 kA cells. Electric power represents about 20 to 40% of the cost of producing aluminium, depending on the location of the aluminium smelter. Smelters tend to be located where electric power is plentiful and inexpensive, such as South Africa, the South Island of New Zealand, Australia, China, Middle-East, Russia, Iceland and Quebec in Canada. China is currently (2004) the top world producer of aluminium. Suriname depends on aluminium exports for 70% of its export earnings.[http://www.cia.gov/cia/publications/factbook/geos/ns.html#Econ]

Isotopes

Aluminium has nine isotopes, whose mass numbers range from 23 to 30. Only Al-27 (stable isotope) and Al-26 (radioactive isotope, t_1/2 = 7.2 × 10⁵ y) occur naturally, however Al-27 has a natural abundance of 100%. Al-26 is produced from argon in the atmosphere by spallation caused by cosmic-ray protons. Aluminium isotopes have found practical application in dating marine sediments, manganese nodules, glacial ice, quartz in rock exposures, and meteorites. The ratio of Al-26 to beryllium-10 has been used to study the role of transport, deposition, sediment storage, burial times, and erosion on 10⁵ to 10⁶ year time scales. Cosmogenic Al-26 was first applied in studies of the Moon and meteorites. Meteorite fragments, after departure from their parent bodies, are exposed to intense cosmic-ray bombardment during their travel through space, causing substantial Al-26 production. After falling to Earth, atmospheric shielding protects the meteorite fragments from further Al-26 production, and its decay can then be used to determine the meteorite's terrestrial age. Meteorite research has also shown that Al-26 was relatively abundant at the time of formation of our planetary system. Possibly, the energy released by the decay of Al-26 was responsible for the remelting and differentiation of some asteroids after their formation 4.6 billion years ago.

Clusters

In the journal Science of 14 January 2005 it was reported that clusters of 13 aluminium atoms (Al₁₃) had been made to behave like an iodine atom; and, 14 aluminium atoms (Al₁₄) behaved like an alkaline earth atom. The researchers also bound 12 iodine atoms to an Al₁₃ cluster to form a new class of polyiodide. This discovery is reported to give rise to the possibility of a new characterisation of the periodic table: superatoms. The research teams were led by Shiv N. Khanna (Virginia Commonwealth University) and A. Welford Castleman Jr (Penn State University). [http://www.science.psu.edu/alert/Castleman1-2005.htm]

Precautions

Aluminium is one of the few abundant elements that appears to have no beneficial function in living cells, but a few percent of people are allergic to it — they experience contact dermatitis from any form of it: an itchy rash from using styptic or antiperspirant products, digestive disorders and inability to absorb nutrients from eating food cooked in aluminium pans, and vomiting and other symptoms of poisoning from ingesting such products as Rolaids , Amphojel, and Maalox (antacids). In other persons, aluminium is not considered as toxic as heavy metals, but there is evidence of some toxicity if it is consumed in excessive amounts, although the use of aluminium cookware, popular because of its corrosion resistance and good heat conduction, has not been shown to lead to aluminium toxicity in general. Excessive consumption of antacids containing aluminium compounds and excessive use of aluminium-containing antiperspirants are more likely causes of toxicity. It has been suggested that aluminium may be linked to Alzheimer's disease, although that research has recently been refuted; aluminium accumulation may be a consequence of the Alzheimer's damage, not the cause. In any event, if there is any toxicity of aluminium it must be via a very specific mechanism, since total human exposure to the element in the form of naturally occurring clay in soil and dust is enormously large over a lifetime. Care must be taken to prevent aluminium from coming into contact with certain chemicals that can cause it to corrode quickly. For example, just a small amount of mercury applied to the surface of a piece of aluminium can break up the normal aluminium oxide barrier usually present. Within a few hours, even a heavy structural beam can be significantly weakened. For this reason, mercury thermometers are not allowed on many airliners, as aluminium is a common structural component in aircraft.

Spelling

Etymology / Nomenclature history

In 1808, Humphry Davy originally proposed the name alumium while trying to isolate the new metal electrolytically from the mineral alumina. In 1812 he changed the name to aluminum to match its Latin root. The same year, an anonymous contributor to the Quarterly Review objected to aluminum, and proposed the name aluminium. :Aluminium, for so we shall take the liberty of writing the word, in preference to aluminum, which has a less classical sound. (Q. Review VIII. 72, 1812) This had the advantage of conforming to the -ium suffix precedent set by other newly discovered elements of the period: potassium, sodium, magnesium, calcium, and strontium (all of which Davy had isolated himself). Nevertheless, -um spellings for elements were not unknown at the time: platinum, which had been known to Europeans since the 16th century, molybdenum, which was discovered in 1778, and tantalum, which was discovered in 1802, all have spellings ending in -um. Curiously, the United States adopted the -ium for most of the 19th century with aluminium appearing in Webster's Dictionary of 1828. However in 1892 Charles Martin Hall used the -um spelling in an advertising handbill for his new efficient electrolytic method for the production of aluminium, despite using the -ium spelling in all of his patents filed between 1886 and 1903. It has consequently been suggested that the spelling on the flyer was a simple spelling mistake rather a deliberate choice to use the -um spelling. Hall's domination of production of the metal ensured that the spelling aluminum became the standard in North America, even though the Webster Unabridged Dictionary of 1913 continued to use the -ium version. In 1926, the American Chemical Society officially decided to use aluminum in its publications, and American dictionaries typically label the spelling aluminium as a British variant.

Present day spelling

In the English-speaking world, the spellings (and associated pronunciations) aluminium and aluminum are both in common use in both scientific and nonscientific contexts. In the United States, the spelling aluminium is largely unknown, and the spelling aluminum predominates. Elsewhere in the English-speaking world the spelling aluminium predominates, and the spelling aluminum is largely unknown. However, in Canada both spellings are common, due to the multiple influences on the language of its proximity to the United States, its British colonial past and the large number of native French speakers. Outside English, the "ium" spelling is widespread: the word is aluminium in French and German, and identical or similar forms are used in many other languages. Consequently it is the more common of the two spellings in global terms, even though there may be more users of aluminum in the English-speaking world. The International Union of Pure and Applied Chemistry (IUPAC) adopted aluminium as the standard international name for the element in 1990, but three years later recognised aluminum as an acceptable variant. Hence their periodic table includes both, but places aluminium first [http://www.iupac.org/reports/periodic_table/index.html]. IUPAC officially prefers the use of aluminium in its internal publications, although several IUPAC publications use the spelling aluminum.[http://www.iupac.org/cgi-bin/htsearch?sort=score&restrict=www.iupac.org%2Fpublications%2Fci&config=htdig&restrict=&exclude=www.iupac.org%2Fgoldbook%2F&words=aluminum&submit=]

Chemistry

Oxidation state 1

- AlH is produced when aluminium is heated at 1500 °C in an atmosphere of hydrogen.
- Al₂O is made by heating the normal oxide, Al₂O₃, with silicon at 1800 °C in a vacuum.
- Al₂S can be made by heating Al₂S₃ with aluminium shavings at 1300 °C in a vacuum. It quickly disproportionates to the starting materials. The selenide is made in a parallel manner.
- AlF, AlCl and AlBr exist in the gaseous phase when the tri-halide is heated with aluminium.

Oxidation state 2

- Aluminium suboxide, AlO can be shown to be present when aluminium powder burns in oxygen.

Oxidation state 3

- Fajans rules show that the simple trivalent cation Al³⁺ is not expected to be found in anhydrous salts or binary compounds such as Al₂O₃. The hydroxide is a weak base and aluminium salts of weak bases, such as carbonate, can't be prepared. The salts of strong acids, such as nitrate, are stable and soluble in water, forming hydrates with at least six molecules of water of crystallization.
- Aluminium hydride, (AlH₃)_n, can be produced from trimethylaluminium and an excess of hydrogen. It burns explosively in air. It can also be prepared by the action of aluminium chloride on lithium hydride in ether solution, but cannot be isolated free from the solvent.
- Aluminium carbide, Al₄C₃ is made by heating a mixture of the elements above 1000 °C. The pale yellow crystals have a complex lattice structure, and react with water or dilute acids to give methane. The acetylide, Al₂(C₂)₃, is made by passing acetylene over heated aluminium.
- Aluminium nitride, AlN, can be made from the elements at 800 °C. It is hydrolysed by water to form ammonia and aluminium hydroxide.
- Aluminium phosphide, AlP, is made similarly, and hydrolyses to give phosphine.
- Aluminium oxide, Al₂O₃, occurs naturally as corundum, and can be made by burning aluminium in oxygen or by heating the hydroxide, nitrate or sulfate. As a gemstone, its hardness is only exceeded by diamond, boron nitride and carborundum. It is almost insoluble in water.
- Aluminium hydroxide may be prepared as a gelatinous precipitate by adding ammonia to an aqueous solution of an aluminium salt. It is amphoteric, being both a very weak acid, and forming aluminates with alkalis. It exists in various crystalline forms.
- Aluminium sulfide, Al₂S₃, may be prepared by passing hydrogen sulfide over aluminium powder. It is polymorphic.
- Aluminium fluoride, AlF₃, is made by treating the hydroxide with HF, or can be made from the elements. It consists of a giant molecule which sublimes without melting at 1291 °C. It is very inert. The other trihalides are dimeric, having a bridge-like structure.
- Organo-metallic compounds of empirical formula AlR₃ exist and, if not also giant molecules, are at least dimers or trimers. They have some uses in organic synthesis, for instance trimethylaluminium.
- Alumino-hydrides of the most electropositive elements are known, the most useful being lithium aluminium hydride, Li[AlH₄]. It decomposes into lithium hydride, aluminium and hydrogen when heated, and is hydrolysed by water. It has many uses in organic chemistry. The aluminohalides have a similar structure.

Aluminium in popular culture

- In the film Star Trek IV: The Voyage Home, Scotty devises the fictional material transparent aluminum.

References

- [http://periodic.lanl.gov/elements/13.html Los Alamos National Laboratory – Aluminum]
- [http://www.worldwidewords.org/articles/aluminium.htm World Wide Words] A history of the spelling of aluminium from a British viewpoint.
- Oxford English Dictionary Entries "aluminum" and "aluminium", available by subscription. [http://www.oed.com]

External links

- [http://www.webelements.com/webelements/elements/text/Al/index.html WebElements.com – Aluminium]
- [http://www.world-aluminium.org/ World Aluminium]
- [http://www.indexmundi.com/en/commodities/minerals/aluminum/aluminum_table12.html World production of primary aluminum, by country]
- [http://www.saanet.org/kashipur/docs/seenalum.htm Social and Environmental Impact of the Aluminium Industry]
- [http://153rd.com/sam/as/physics/aluminium/normal/redirect.html Sam's Aluminium Information Site] Patents
- US[http://patft.uspto.gov/netacgi/nph-Parser?Sect1=PTO1&Sect2=HITOFF&d=PALL&p=1&u=/netahtml/srchnum.htm&r=1&f=G&l=50&s1=400664.WKU.&OS=PN/400664&RS=PN/400664 400664] – Process of reducing aluminum from its floride salts by electrolysis – C. M. Hall Category:Chemical elements Category:Poor metals Category:Pigments Category:Pyrotechnic chemicals Category:Rocket fuels ko:알루미늄 ja:アルミニウム simple:Aluminium th:อะลูมิเนียม

Coors

The Coors Brewing Company was one of the world’s largest brewers. On February 9, 2005 Coors completed its merger with Canadian brewer Molson to create the world’s fifth-largest brewing company, the Molson Coors Brewing Company.

History

The Coors Brewing Company is the principal subsidiary of the Adolph Coors Company. In 1873, German immigrant Adolph Coors established a brewery in Golden, Colorado. His American lager, nicknamed the “Banquet Beer” and now known as “Coors Original,” is said to take its flavor from the pure water of the Rocky Mountains. Coors’ company survived the prohibition era in America by producing malted milk and other related products. Prohibition also led the company to enter the ceramics industry, making products under the name Coors Ceramics. This business was later spun off as CoorsTek. For much of its history, Coors was a regional product mostly confined to the American west. This made it a novelty on the east coast, and visitors returning from visits to the western states often made a point of bringing back a case. This iconic status was reflected in pop culture: in 1977 the movie Smokey and the Bandit centered around an illegal shipment of Coors from Texas to Georgia. The company finally established nationwide distribution in the U.S. in the early 1990s. Coors introduced the aluminum can. aluminum canIn 2003, Coors was the third largest producer of beer in the United States, and the second largest brewer in the United Kingdom through its subsidiary, Coors Brewing Limited. There it controls the UK’s most popular brew, Carling. On July 22, 2004 the company announced it would be merging with Canadian brewer Molson. The merger was completed February 9, 2005 and the merged company is called Molson Coors Brewing Company. Through its owners and foundation, Coors also has played a prominent role in American politics and public policy, supporting many conservative causes, including The Heritage Foundation, one of the world’s most influential conservative public policy research institutes. Chairman Pete Coors ran unsuccessfully for the U.S. Senate from Colorado in 2004 on the Republican ticket.

Product lines

United States

Republican Beers
- Coors
- Coors Original, the "Banquet Beer"
- Coors Light, the "Silver Bullet"
- Coors Extra Gold
- Killian’s
- Blue Moon (wheat beer)
- Keystone Others
- Zima
- Aspen Edge
- Winterfest (Seasonal)

UK

Beers
- Allbright
- Arc
- Breaker
- Caffrey’s
- Carling
- Coors
- Hancock’s
- Lamot
- M & B
- Stones
- Toby
- Worthington Others
- Abis
- Java
- Red
- Reef
- Screamers

Diversity

Coors received a 100% rating on the Corporate Equality Index released by the Human Rights Campaign starting in 2004, the third year of the report.

External links

- [http://www.coors.com/ Coors Brewing Company] (USA).
- [http://www.coorsbrewers.com/ Coors Brewers Limited] (UK).
- .
- [http://www.bamn.com/boycott-coors/index.asp "Coors & Affirmative Action"].
- [http://www.namebase.org/sources/NT.html Summary of The Coors Connection, a book on the Coors’ family support for conservative organizations]. Category:American breweries Category:Companies based in Colorado

Cylinder (geometry)

In mathematics, a cylinder is a quadric, i.e. a three-dimensional surface, with the following equation in Cartesian coordinates: :

\left(\frac\right)^2 + \left(\frac\right)^2 = 1

This equation is for an elliptic cylinder, a generalization of the ordinary, circular cylinder (a = b). Even more general is the generalized cylinder: the cross-section can be any curve. The cylinder is a degenerate quadric because at least one of the coordinates (in this case z) does not appear in the equation. By some definitions the cylinder is not considered to be a quadric at all. In common usage, a cylinder is taken to mean a finite section of a right circular cylinder with its ends closed to form two circular surfaces, as in the figure (right). If the cylinder has a radius r and length h, then its volume is given by :

V = \pi r^2 h \,

and its surface area is :

A = 2 \pi r ( r + h ) \,

For a given volume, the cylinder with the smallest surface area has h = 2r. For a given surface area, the cylinder with the largest volume has h = 2r. There are other more unusual types of cylinders. These are the imaginary elliptic cylinders: :

\left(\frac\right)^2 + \left(\frac\right)^2 = -1

the hyperbolic cylinder: :

\left(\frac\right)^2 - \left(\frac\right)^2 = 1

and the parabolic cylinder: :

x^2 + 2y = 0 \,

External links

- [http://www.mathsisfun.com/geometry/cylinder.html Spinning Cylinder] Math Is Fun Category:Elementary geometry Category:Euclidean solid geometry ja:円柱 (数学)

Cone

A cone is a basic geometrical shape: see cone (solid). Several things have also been called "cones" on account of their shape:
- A volcanic cone is a mountain formed by material ejected from a volcanic vent.
- In relativity, the light cone of an event consists of all spacetime events that can interact with it.
- The scaly fruit-like reproductive bodies of certain plants, especially conifers and cycads, are called cones: see conifer cone.
- In vertebrate anatomy, a cone cell is a type of light-sensitive cell found along with rods in the retina of the eye.
- In ceramics manufacture, a pyrometric cone is a conical or pyramidal mineral stick that is used to gauge the temperature of an oven.
- An ice cream cone is a container for ice cream, shaped like an inverted cone open at its top. It is often made of edible pastry.
- A traffic cone is a brightly colored cone-shaped plastic object commonly used as a temporary traffic barrier or warning sign.
- In basketball, a cone is a player who is so slow and unskilled that he can be dribbled around as if he was a traffic cone.
- Cone is the bassist for the Canadian band Sum 41.
- Fairfax M. Cone was an American advertising executive sometimes called the "father of modern advertising".
- To 'smoke a cone', using a bong and a Conepiece is a term used by Marijuana smokers. The word cone and its derivatives also have several specialized meanings in mathematics:
- In geometry,
- cone (geometry)
- cone (surface)
- cone (solid)
- Also in geometry, the cone of an arbitrary set

X

means the union of all line segments connecting a fixed point to points of

X

. For example, this coning operation will turn a triangle into a tetrahedron.
- In topology, too, coning may be applied to a topological space, e.g. to define the barycentric subdivision of a cell complex; see cone (topology).
- In linear algebra, the convex cone of a set of vectors consists of all linear combinations of those vectors with non-negative coefficients.
- In graph theory, a cone graph is a graph with a universal vertex (a vertex that is connected to all others vertices).
- In descriptive geometry, "conical projection" is another name for the perspective projection.
- In cartography, however, a conical projection maps the spherical surface of the Earth to a conical surface, that is then unrolled onto a plane.
- A conic section is any curve obtained by cutting the surface of a cone (more precisely, a conical surface) by an arbitrary plane. ja:円錐

Aluminium

Properties

Applications

Engineering use

Household wiring

History

Natural occurrence

Isotopes

Clusters

Precautions

Spelling

Etymology / Nomenclature history

Present day spelling

Chemistry

Oxidation state 1

Oxidation state 2

- Aluminium suboxide, AlO can be shown to be present when aluminium powder burns in oxygen.

Oxidation state 3

Aluminium in popular culture

- In the film Star Trek IV: The Voyage Home, Scotty devises the fictional material transparent aluminum.

References

External links

Recycling

Recycling is the collection of used materials that would otherwise be waste to be broken down and remade into new products. Similarly, reuse is collecting waste such as food and drink containers to be cleaned, refilled and resold. Motivations for recycling include environmental sustainability and financial concerns: sustainability because the reused material both prevents waste and reduces the consumption of new raw materials, and financial because it can be cheaper to produce to products from reused or recycled materials. An extensive variety of waste is recyclable, and commonly recycled materials include glass, paper, aluminum, asphalt, and steel. These materials can be derived either from pre-consumer waste (materials used in manufacturing) or post-consumer waste (materials discarded by the consumer).

Overview

Many manufactured products are not readily biodegradable and take up space in landfills or must be incinerated. Recycling is an alternative to this. In theory, recycling would allow a continuing reuse of materials for the same purpose. In practice, recycling most often extends the useful life of a material, but in a less-versatile form. For example, when paper is recycled, the fibers shorten, making it less useful for high grade papers. Other materials can suffer from contamination, making them unsuitable for food packaging. Consumer recycling has succeeded mostly in reducing industrial consumption of energy and water. Production of materials such as aluminum or glass requires large amounts of electricity or fossil fuels. The recycling of such materials is profitable and prevents a substantial amount of greenhouse gas emissions. Skeptics believe that, with the exception of aluminum cans, recycling is wasteful. In particular, the market for recycled materials is limited, and using recycled materials may be more expensive for manufacturers than new raw materials. However, recycling becomes relatively cheaper when externalities associated with raw material extraction and landfill (or incineration) are included, especially environmental and health effects. Recycling may still be socially efficient even when carried out at a financial loss - although an alternative to avoid this would be to tax raw material use appropriately so that prices fully reflect all the costs involved, instead of subsidising recycling. Of the 24 OECD-countries where figures were available, only 16% of household waste was recycled in 2002.

US issues

State support for recycling may be more expensive than alternatives such as landfill; recycling efforts in New York City in the USA cost $57 million per year.¹ A number of U.S. states, such as Oregon, Connecticut, Delaware, Maine, Vermont, Massachusetts, Iowa, Michigan and New York have passed laws that establish deposits or refund values on beverage containers in order to promote recycling. beverage.]] beverage.]]

Reuse

One form of recycling is the reuse of goods, especially bottles. Reuse is distinguished from most forms of recycling, where the good is reduced to a raw material and used in the making of a new good (eg crushing of bottles to make glass for new bottles). Refillable bottles are used extensively in many European countries; for example in Denmark, 98% of bottles are refillable, and 98% of those are returned by consumers. [http://www.alternet.org/envirohealth/21651/] These systems are typically supported by deposit laws and other regulations. In some developing nations like India, concerns over the cost factor often force manufacturers to use refilled glass bottles for selling cola and other drinks thus creating a reuse process inadvertently. India also has a way of reusing old newspapers as "Kabadiwalas" buy these from the readers for scrap value and reuse them in packaging or in recycling plants. These scrap intermediaries also help in disposing other articles and metals from the consumers and is a lucrative business for the resellers. In the former East Germany, organic household waste was collected and used as fodder for pigs. This integrated system was made possible by the state's control of agriculture; the complexities of continuing it in a market economy after German reunification meant the system had to be discontinued. Organic household waste is still collected separately in some towns in Germany, and may be used for fertiliser or landfilled in more sensitive locations where other waste cannot be. In North America, organic household waste, especially yard waste such as leaves on a seasonal basis, is often collected and heaped up to form compost.

History

compost Recycling is generally at its peak during wartimes or energy shortages. Massive government promotion campaigns were carried out in World War II in every country involved in the war, urging citizens to conserve metals and fiber. These resource conservation programs established during the war were continued in some natural resource-poor countries, such as Japan, after the war ended. In the USA, the next big investment in recycling occurred in the 1970s, due to rises in energy costs (recycling aluminum uses only 5% of the energy required by virgin production; glass, paper and metals have less dramatic but very significant energy savings when recycled feedstock is used). The passage of the Clean Water Act in the USA created strong demand for bleached paper (office paper whose fiber has already been bleached white increased in value as water effluent became more expensive). On September 17, 1981, the first ever blue box recycling program was launched in Kitchener, Ontario, Canada. Today, more than 90% of Ontario households have access to recycling programs and annually they divert more than 650,000 tonnes of secondary resource materials. The "blue box" program has expanded in various forms throughout Canada and to countries around the world such as United Kingdom, France and Australia, serving more than 40 million households in countries around the world. The modern recycling movement, associated with avoided solid waste disposal costs in the United States, began in 1987 when a barge called the Mobro 4000, containing a little over 3,000 tons of garbage departed from Islip, New York to deposit its load of garbage in Morehead City, North Carolina. However, before it reached its destination, rumors that it contained medical waste caused officials at Morehead City to deny the barge permission to unload its garbage. As a result, the barge traveled down the East coast of the United States searching for a place to unload, eventually being denied in Mexico and Belize. The barge finally returned to Islip, where the trash was incinerated after a brief legal battle. The barge's journey became a small media event in 1987 which culminated in environmentalists claiming that the United States had run out of landfill space, if it had no room for one single barge. Although scientists disagreed then, and still disagree with this claim, the modern recycling movement had begun.[http://www.bos.frb.org/economic/nerr/rr2002/q1/waste.htm] [http://www.paperloop.com/db_area/archive/p_p_mag/2005/0001/editors.html] [http://www.williams.edu/HistSci/curriculum/101/garbage.html] environmentalist Another major event that initiated recycling efforts occurred in 1989 when the city of Berkeley, California, banned the use of polystyrene packaging for keeping McDonald's hamburgers warm. One effect of this ban was to raise the ire of management at Dow Chemical, the world’s largest manufacturer of Polystyrene, which led to the first major efforts to show that plastics can be recycled. By 1999, there were 1,677 companies in the USA alone involved in the post-consumer plastics recycling business.