Structure of Aluminium
When solid, the of aluminium is cubic close-packed.
History
Aluminium is never found in its metallic form in nature. It occurs as , a mixture of aluminium oxides, iron oxides and clay.
Being so difficult to isolate, aluminium wasn't discovered until 1807, by Sir Humphry Davy (who also discovered potassium and sodium and invented the miner's safety lamp). It was not until 1825 that aluminium was isolated as a metal by Danish physicist Hans Christian Orsted. It was a further 60 years before a commercial production method was developed. In 1886 the electrolytic process that splits oxygen from , allowing the molten metal to be poured off, was discovered simultaneously by Paul Heroult in France and by Charles Martin Hall in the USA.
- 1808 Sir Humphry Davy (Britain) established the existence of aluminium and named it.
- 1821 P. Berthier (France) discovers a hard, reddish, clay-like material containing 52 per cent aluminium oxide near the village of Les Baux in southern France. He called it bauxite, the most common ore of aluminium.
- 1825 Hans Christian Oersted (Denmark) produces minute quantities of aluminium metal by using dilute potassium amalgam to react with anhydrous aluminium chloride, and distilling the resulting mercury away to leave a residue of slightly impure aluminium.
- 1827 Freidrich Wöhler (Germany) describes a process for producing aluminium as a powder by reacting potassium with anhydrous aluminium chloride.
- 1845 Wöhler establishes the specific gravity (density) of aluminium, and one of its unique properties - lightness.
- 1854 Henri Sainte-Claire Deville (France) improves Wöhler's method to create the first commercial process. The metal's price, initially higher than that of gold and platinum, drops by 90% over the following 10 years. The price is still high enough to inhibit its widespread adoption by industry.
- 1855 A bar of aluminium, the new precious metal, is exhibited at the Paris Exhibition.
- 1885 Hamilton Y. Cassner (USA) improves on Deville's process. Annual output 15 tonnes
- 1886 Two unknown young scientists, Paul Louis Toussaint Héroult (France) and Charles Martin Hall (USA), working separately and unaware of each other's work, simultaneously invent a new electrolytic process, the Hall-Héroult process, which is the basis for all aluminium production today. They discovered that if they dissolved aluminium oxide (alumina) in a bath of molten cryolite and passed a powerful electric current through it, then molten aluminium would be deposited at the bottom of the bath.
Aluminium has only been produced commercially for 146 years and is still a very young metal. Mankind has been using copper, lead and tin for thousands of years and yet today more aluminium is produced than all other non-ferrous metals combined. Annual primary production in 1999 was about 24 million tonnes and secondary - recycled - production to some 7 million tonnes. The total of some 31 million tonnes compares with 14.1 million tonnes of copper, 6.0 million tonnes of lead and 0.2 million tonnes of tin.
Uses
Aluminium is the second most widely used metal in the world today.
- It is used extensively in aircraft
- In building construction
- In consumer durables such as fridges cooking utensils and air conditioners as well as in food processing equipment
- Before the middle of the 19th century though, the cost of aluminium production was so high that the metal was considered to be 'semi precious'. Louis Napoleon, Emperor of France, even had a ceremonial helmet and dinner service made of aluminium
- The first major commercial use of aluminium was cookware
Nowadays,
- Cans and foils
- Kitchen utensils
- Outside building decoration
- Industrial applications where a strong, light, easily constructed material is needed
- Although its electrical conductivity is only about 60% that of copper per area of cross section, it is used in electrical transmission lines because of its lightness and price
- Alloys are of vital importance in the construction of modern aircraft and rockets
- Aluminium, evaporated in a vacuum, forms a highly reflective coating for both visible light and radiant heat. These coatings soon form a thin layer of the protective oxide and do not deteriorate as do silver coatings. These coatings are used for telescope mirrors, decorative paper, packages, toys, and in many other uses
Aluminium and the environment
The Australian aluminium industry has long been at the forefront of world environmental excellence in all aspects of its operations - from rehabilitation of its bauxite mines to emission control at the smelters. Since the industry started in Australia, recycling has been recognised as a way of saving energy and reducing pollution. Australian aluminium producers were among the first to recognise the secondary use of aluminium during the 1940s, and by the 1970s had established an extensive network of aluminium scrap collection points around the country. Recycling aluminium represents a 95% saving of energy needed to produce aluminium from .
Conclusion
From all the research I have done I can clearly say that the aluminium is a well-used metallic material. From my notes you can see that it has a history of over 100 years and also well used.
Bibliography
A very good website but it does not go into detail of key dates as this is very brief but to the point including main points and uses such as soda cans.
This was a detailed website that covered most aspects of my report as this had precise dates measurements and also went into detail as who first discovered aluminium.
Another detailed website that corroborated all my findings so and also gave some more detailed notes on uses of aluminium and mainly concentrated on procedures producing cans that was the main down point of this website.
This was a more chemistry based website that dealt with the structure shape and also appearance of the metal, there were no major differences in history as all websites agreed that it was sir Humphry who first discovered aluminium.
The Aluminium Industry www. Server was providing information about organisations and corporations active in or related to the production of aluminium and aluminium products. Not as effective as most other used recourses.
Dedicated to aluminium production and processing, the site was not as useful as other websites as this was more up to date and conclusive as this showed jobs and uses up to date in the aluminium industry.
I also used an As physics textbook but unfortunately this had no information on my chosen material but it helped explain many aspects such as the conductivity and structure. It also gave me ideas on what to include in my report.