1. Aluminium
Extraction and Uses

2. Aluminium Mining Aluminium Ore is called Bauxite.
Bauxite is a red mineral made of aluminium oxide and iron oxides.
Bauxite is mined in various places, e.g. Russia, Jamaica

3. Bauxite Purification Bauxite is heated with sodium hydroxide.
This dissolves the alumina but not the other minerals.
The residue is filtered off and disposed of.
The filtrate is acidified and heated to produce pure alumina, aluminium oxide powder.

4. Extracting aluminium Aluminium is more reactive than carbon.
So carbon will not reduce aluminium oxide.
Aluminium cannot be extracted in a blast furnace.
Aluminium is extracted using electricity in a process called electrolysis.

5. The electrolysis cell

6. How it works + Direct Current Al2O3 2Al3+ + 3O2- Anode Al3+ O2- O2-
Cathode -

7. At the anode 2O2-  O2 + 4e- O2 + C  CO2 + anode e- e- O2- O2 O2- CO2
positive
O2 + C  CO2

8. At the cathode Al3+ + 3e-  Al - al l i q u i d Cathode e- e- e- Al3+
negative

9. Quick Review + + Direct Current Anode Anode CO2 CO2 O2 Al3+ O2- O2-
Cathode -

10. At the electrodes. At the negative cathode
Positive Aluminium ions drift to the cathode.
They gain electrons and become aluminium atoms
Al3+ + 3e-  Al
At the positive anode
Negative oxide ions drift to the positive anode.
They lose electrons and become oxygen gas molecules.
2O2-  O2 + 4e-

11. Making stuff

12. Uses of aluminium Power cables Saucepans Aeroplanes Bicycles Cars
Battleships
Cooking foil
Cans
Space blankets
Statues
Window frames
Light
Light, unreactive
Light, doesn’t rust
Light, radar quiet
Reflective, unreactive
Unreactive
Reflective