Abstract: In view of the fact that the formulas for standard molar Gibbs free energy change of iron oxides reduction which used in our previous research work are not precise, the impact of stored energy on gas-based reduction thermodynamics of iron oxides are further investigated based on new induced formulas. Except for correcting four errors in previous work, it is found out that FeO gas-based reduction itself is not affected by the starting temperature. But in the Fe₃O₄ reduction gas-based reduction system, FeO reduction owns the same starting temperature as Fe₃O₄ reduction in transition temperature. the temperature for the transition of the Fe₃O₄ reduction decreases linearly with the increase of stored energy for Fe₃O₄, so the reduction of Fe₃O₄ and FeO occurs at the traditional 570 ℃ below when the stored energy for Fe₃O₄ is started. Meanwhile, the equilibrium CO (H₂) pressure fraction corresponding to the aforementioned transition temperature decreases (increases) with the increase of stored energy for Fe₃O₄, that is, CO reduction forked curve moves in the direction of low temperature and low CO pressure fraction while H₂ reduction forked curve moves in the direction of low temperature and high H₂ pressure fraction.

Key words: Mechanical activation, Stored energy, CO reduction, H₂ reduction, Thermodynamics, Fork curve