FeO*Fe2O3 + 4 CO → 3 Fe + 4 CO2
This is an oxidation-reduction (redox) reaction:
4 CII - 8 e- → 4 CIV (oxidation)
FeII + 2 e- → Fe0 (reduction)
2 FeIII + 6 e- → 2 Fe0 (reduction)
CO is a reducing agent, FeO*Fe2O3 is an oxidizing agent, FeO*Fe2O3 is an oxidizing agent.