Elucidation of Reaction Mechanism and Evaluation of Rate of Iron Oxide Reduction with Gas Mixtures including Methane

由于众所周知的还原动力学，氧化铁球团被用作铁矿石样品。将重2kg的球团装入反应器中，用CH_4-N_2、CH_4-H_2 O-N_2和CH_4-CO_2-N_2等混合气体进行等温还原。在动力学分析的基础上，利用反应模型阐明了反应机理并评价了还原率。采用三界面未反应核收缩模型对单颗粒H_2-H_2 O-N_2或CO-CO_2-N_2混合气体还原实验数据进行拟合，得到了H_2或CO还原的速率参数。对甲烷在铁系催化剂上的热分解进行了实验研究。考察了含CH_4混合气还原氧化铁的最佳条件，获得了分析煤碳化气预还原氧化铁的基础数据，同时考察了煤的碳化条件和氧化铁的还原条件，提出了最佳条件。

Iron oxide pellets were used as iron ore samples because of the well-known reduction kinetics. The pellets weighing 2kg were packed in a reactor and reduced isothermally with gas mixtures such as CH_4-N_2, CH_4-H_2O-N_2, and CH_4-CO_2-N_2. Elucidation of the reaction mechanism and evaluation of the reduction rate were carried out on the basis of the kinetic analysis using reaction models. Unreacted core shrinking model for three interfaces were adopted to the experimental reduction data of single particles with H_2-H_2O-N_2 or CO-CO_2-N_2 gas mixture, and rate parameters for H_2 or CO reduction were evaluated. Thermal decomposition of methane with iron catalyst was experimentally carried out. Optimum conditions for iron oxide reduction with CH_4 bearing gas mixtures were examined and fundamental data for analyzing pre-reduction of iron oxide with coal carbonization gas were obtained ; carbonizing conditions of coal and reduction conditions of iron oxide were simultaneously investigated to present the optimum ones.