L1 /   
10
CH1012
THE HALL-HEROULT PROCESS I
Cathode: Al2O3   +   6e- ®      2Al   +   3O2-
Anode:    C   +   2O2-        ®      CO2   +   4e- 
Overall:   2Al2O3   +   3C  ®      4Al   +   3CO2
• The electrolyte
  is cryolite
  ( Na3AlF6) and
  alumina.
• At 1000oC this
  is molten.
• The anode
  is consumed