 Discovery Information
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| Who: Hans Christian Oersted |
| When: 1825 |
| Where: Denmark |
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| Name Origin
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| Latin: alumen (alun). |
| "Aluminium" in different languages. |
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| Sources
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| Most plentiful metal in earth's crust (7.5% - 8.1%), but virtually never occurs in free form, so rare that it was once considered
a precious metal more valuable than gold! Obtained by electrolysis from bauxite (Al2O2).
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| Primary reserves are found in Surinam, Jamaica, Ghana, Indonesia and Russia. Annual production is around 15 million tons. |
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| Abundance
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| Universe: 50 ppm (by weight) |
| Sun: 60 ppm (by weight) |
| Carbonaceous meteorite: 9300 ppm |
| Earth's Crust: 82000 ppm |
| Seawater: |
| Atlantic surface: 9.7 x 10-4 ppm
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| Atlantic deep: 5.2 x 10-4 ppm
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| Pacific surface: 1.3 x 10-4 ppm
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| Pacific deep: 1.3 x 10-5 ppm
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| Human: |
| 900 ppb by weight |
| 210 ppb by atoms |
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| Uses
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| Kitchen utensils, building decorations, electrical transmission (not nearly as conductive as copper, but cheaper) as well as packaging (can, foil etc.). Aluminium alloys form vital components of aircraft and rockets as a result of their high strength to weight ratio. Alloys containing copper, magnesium, silicon, manganese and other metals are much stronger and more durable than aluminium, making aluminium useful in the manufacture of aircraft
and rockets.
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| Most electronic appliances that require cooling of their internal devices (like transistors, CPUs - semiconductors in general)
have heat sinks that 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.
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| Aluminium oxide (Al2O3), alumina, is found naturally as corundum (rubies and sapphires), emery, and is used in glass making. Synthetic ruby and
sapphire are used in lasers.
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| Powdered aluminium is a commonly used silvering agent 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.
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| History
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| The ancient Greeks and Romans used aluminium salts as dyeing mordants and as astringents for dressing wounds. 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 at first named alumium and later aluminum.
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| Friedrich Wöhler is generally credited with isolating aluminium (Latin alumen, alum) in 1827 by mixing anhydrous aluminium chloride with potassium. The metal, however, had indeed been produced for the first time two years earlier - but in an impure form - by the Danish
physicist and chemist Hans Christian Orsted. Therefore, Orsted can also be listed as the discoverer of the metal. Further, Pierre Berthier discovered aluminium in bauxite
ore and successfully extracted it. The Frenchman Henri Etienne Sainte-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.
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| Aluminium was selected as the material to be used for the apex of the Washington Monument, at a time when one ounce (30 grams)
cost twice the daily wages of a common worker in the project; aluminium was a semiprecious metal at that time.
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| Notes
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| It is the second most malleable metal (gold being first) and the sixth most ductile.
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| Hazards
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| 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 antiperspirant
products, digestive disorders and inability to absorb nutrients from eating food cooked in aluminium pans.
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| Aluminium powder is flammable. Reacts very exothermically with halogens.
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