基于最小Gibbs自由能原理的铁氧化物气固还原热力学研究

Thermodynamics of iron oxide gas-solid reduction based on the minimized Gibbs free energy principle

基于最小Gibbs自由能原理建立了铁氧化物气固还原反应的热力学模型,由模型计算结果作出铁氧化物气固还原反应平衡图,与文献中实验数据吻合良好.与常用冶金学教材和热力学数据库中给出的参考数据进行了对比,不同来源的热力学数据差异较大.探究了铁氧化物逐级还原的热力学平衡情况.计算了CO和H2混合气体还原铁氧化物的热力学平衡,推导了平衡时气体总利用率η总的计算公式,作出了CO和H2混合气体还原铁氧化物的三维平衡图,并与文献中实验数据对比,验证了结果的正确性.

A thermodynamic model for gas-solid reduction reactions of iron oxides was established based on the minimized Gibbs free energy principle. On the basis of the model calculation results,the equilibrium diagram for the gas-solid reduction reactions of iron oxides was graphed; the equilibrium results are in good agreement with the reported experimental data. Comparison with the data from common metallurgical books and thermodynamic databases indicates big differences in thermodynamic data from different references. Thermodynamic equilibrium was investigated for the stepwise reduction sequence of iron oxides. The thermodynamic equilibrium was calculated for iron oxide reduction using CO-H2 mixtures as a reducing agent. According to the calculation results,the formula for the gas utilization ratio η总in the equilibrium state was deduced,and the three-dimensional equilibrium diagram of iron oxide reduction using CO-H2 mixtures was graphed. As compared with the reported experimental data indicates the correctness of calculation results.