Extraction of aluminium

• • Extracting metals via electrolysis requires a lot of energy
  • positive AI^3+ ions move towards the cathode and are reduced : AI^3+ + 3e- -> AI
  • cathode ( - ) and carbon anode ( + and needs replacing regularly )
  • Negative O^2- ions move towards the anode and are oxidised : 2O^2- -> O2 + 4e-
  • oxygen gas produced at anode
  • molten aluminium metal at the bottom
  • molten aluminium oxide mixed with cryolite ( to lower the melting point ) .