Fe0-Fe3+-Fe0-Fe2+-Fe(OH)2-Fe(OH)3
Fe + 2HCl = FeCl2 + H2
FeCl2 + 2H2O = Fe(OH)2 + 2HCl
Fe(OH)2 = FeO + H2O
FeO + H2 = Fe + H2O
2Fe + 3Cl2 = 2FeCl3
FeCl3 + Al = Fe + AlCl3
4Fe(OH)2 + O2 + 2H2O = 4Fe(OH)3