Cochise College Student Papers in Geology

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Roger Weller, geology instructor

wellerr@cochise.edu

Aluminum
by Bryson Pantoja
Physical Geology
Spring 2011

Aluminum: The Magic Metal

Whether we realize it or not, aluminum is in our lives every day. Most people hardly pay attention to it, but without it, much of modern living would not be the same. Aluminum is all around us and it is certainly one of the most important metals today. Some items that aluminum is used in are aircraft, cars, door knobs, window frames, packaging, and construction items such as pipes.

http://beyondthebottle.org/?p=70

Aluminum is such a highly versatile material because no other metal has all the properties of aluminum. Some properties of aluminum that make it such a popular choice for making so many items are that aluminum is light weight and as strong as steel if alloyed correctly.

http://www.bombayharbor.com/products/1296/AluminumPipes.html

This makes it a prime choice for aircraft companies because they need a material light enough to get off the ground, but also strong enough to stay up. Another draw is the fact that aluminum is much more cost efficient than other metals. This is probably due, in large, because, if continued mining happens at the same rate it is today, we seem to have enough on the planet to last us for hundreds of years! Another property of aluminum is that it is extremely resistant to corrosion, which makes it an ideal choice for some construction parts. It is also non-toxic, which makes it a prime choice for packaging items

such as soda. Aluminum also has thermal conductivity, and thus can spread both heat and cooling quickly. Perhaps best of all (at least for the environment), aluminum is easily recyclable, which means that little aluminum is wasted. On a quick side note: aluminum does conduct electricity quite well; twice as well as copper, in fact. Unfortunately, aluminum oxide, does not. You can also be sure that, if you have aluminum electrical wiring, it will oxidize. What this means for you: move out of a house with aluminum electrical wiring as soon as possible, because when your wiring oxidizes, it will no longer conduct electricity, but continue to conduct heat. This will start a fire in your house as soon as enough heat is built up in the wiring.

The main source of aluminum in the world comes from an ore specimen called bauxite. Bauxite is primarily composed of aluminum oxide and aluminum hydroxide.

Photo Courtesy of Roger Weller
http://skywalker.cochise.edu/wellerr/mineral/bauxite/bauxiteL.htm

Bauxite can come in a few different colors such as grey, white, yellow, or red, and usually has a dull, earthy luster, or look, to it. To turn bauxite into the usable metal aluminum, the Bayer process is used. The Bayer process involves crushing the bauxite and milling the alumina (also known as aluminum oxide) into smaller chunks that are easier to extract. The alumina is then extracted, and the Hall (sometimes called the Hall-Héroult) process is then implemented.

Photos Courtesy of Roger Weller

http://skywalker.cochise.edu/wellerr/mineral/bauxite/bauxiteL.htm

The Hall process consists of dissolving the extracted alumina in molten cryolite, and then passing an electric current through it. Most (31 percent) of the United States’ bauxite comes from Jamaica. However, other major sources are Guinea (22 percent), Brazil (19 percent), and Guyana (12 percent). The remaining 16% comes from many other countries.

In conclusion, aluminum has many uses which include household, construction, transportation, and packaging purposes. It is a light weight and, if alloyed correctly, extremely hard material. This makes it extremely versatile and invaluable to almost all industries. It is also cheap and abundant, which is why the metal can be used by so many industries. Aluminum is primarily gotten from bauxite, an earthy rock that is the main source of aluminum in the world. So, the next time you look at a car, an airplane, or even your fork, don’t be surprised to find yourself saying, “Wow, what a metal!”

Works Cited

"Aluminum - How Aluminum Is Obtained." Web. 25 Apr. 2011.
http://science.jrank.org/pages/267/Aluminum-How-aluminum-obtained.html

"Bauxite Mineral | Uses and Properties - GEOLOGY.COM."
Geology.com - Earth Science News, Maps, Dictionary, Articles, Jobs. Web. 25 Apr. 2011.
http://geology.com/minerals/bauxite.shtml

"Bayer Process Chemistry." International Aluminium Institute. Web. 26 Apr. 2011.
http://www.world-aluminium.org/?pg=85

Bray, E. Lee. "Bauxite and Alumina." Jan. 2009. Web. 26 Apr. 2011.
http://minerals.usgs.gov/minerals/pubs/commodity/bauxite/mcs-2009-bauxi.pdf

Davyson, Sam. "Aluminum Uses." Sam Davyson. Web. 25 Apr. 2011.
http://sam.davyson.com/as/physics/aluminium/siteus/uses.html

Shivade, Madhumita. "Aluminum: Uses of Aluminum." Buzzle Web Portal: Intelligent Life on the Web. 22 Feb. 2010. Web. 25 Apr. 2011. http://www.buzzle.com/articles/aluminum-uses-of-aluminum.html
Weller, Roger. “Aluminum Oxide Interview” Interview by Bryson P. Pantoja. Personal Interview.

Photo Credits

http://beyondthebottle.org/?p=70

http://www.bombayharbor.com/products/1296/AluminumPipes.html

http://skywalker.cochise.edu/wellerr/mineral/bauxite/bauxiteL.htm