Extraction of Aluminum By Peter Bassett and Ben Reading-Thompson

What is Aluminum? Aluminum is the most abundant metal on Earth. It is found in Group 3 of the periodic table It is only recently in the 21 st century that it has been put to use because beforehand it was expensive and difficult to extract and purify It is known for it’s light but strong metal Today due to it’s properties it is used in many things from aluminum foil to cars and planes

How is it extracted? Aluminum is found in an ore called Bauxite Most of the bauxite is found only a few meters below the surface of the Earth Every six tones of bauxite only produces one tone of aluminum Before the extraction process begins the bauxite is grounded down to the consistency of sand Then it goes through a two step system to extract the aluminum

Step 1: Extracting Aluminum Oxide To obtain the aluminum oxide from the Bauxite we use a technique called the Bayer process Sulfuric Acid is first added to the bauxite in which the silicon and aluminum will dissolve. The remaining impurities are filtered off. Carbon Dioxide is then bubbled through the mixture causing the aluminum oxide to precipitate. The reaming mixture is then filtered again to get rid of any impurities The water is then boiled off leaving purified aluminum oxide

Step 2: Separating Aluminum Oxide The Hall-Heroult method is used to separate the aluminum oxide The aluminium oxide is first mixed with cryolite and then heated to 980 degrees Celsius to melt the solids The mixture is then elextrolysed with a very large current. The oxygen gas is formed at the anodes which are made of carbon so that it forms carbon dioxide The aluminium metal is formed at the cathode

Discussion This is the most efficient and least expensive method currently in use It is still very expensive as it requires large amount of energy to obtain the aluminum metal although it is competitively priced with other metals unlike earlier in history.

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