Thursday, 16 May 2013

5.2 describe and explain the extraction of aluminium from purified aluminium oxide by electrolysis


  • Bauxite is purified into aluminium oxide.
  • This is then dissolved in molten cryolite to bring down the boiling point
  • The walls of the tank are the negative electrode; here aluminium is made
  • The aluminium sinks to the bottom and is tapped off
  • Oxygen is formed at the positive electrode
  • The oxygen formed reacts with the graphite anode to from carbon dioxide; so the anode has to be replaced
It is very expensive to supply the electricity needed for this electrolysis.

7 comments:

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  2. vvvvvvvvvvvvvvvvvvvvvvvvvvvvvwvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvv

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    Replies
    1. Thanks dude,
      That was some very useful input

      Delete
  3. Replies
    1. steel tank lined with heat resistant bricks, but doubt you need to know that

      Delete
  4. Thanks so much for this wonderful blog! Just one thing: think it should be "bring down the melting point" rather than "bring down the boiling point".

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