H_2-CO混合气体还原氧化亚铁粉体的动力学

Reduction kinetics of FeO powder with H_2-CO mixtures

通过热重实验获得了873、973和1173 K三个温度条件下不同组成的H_2-CO混合气体还原氧化亚铁的动力学曲线,发现在873和973 K时由于析碳反应的发生,动力学曲线较为混乱,没有规律,而在1 173 K时,还原曲线则随还原气体中H_2含量(体积分数)的增加表现出明显的规律性.通过H_2-CO与H_2-Ar气体还原氧化亚铁动力学的比较,混合气体中CO参与反应的速率与其含量(体积分数)基本符合线性关系.还原产物形貌观察的结果表明,随着反应温度的升高,还原产物孔隙增大,铁相充分发育长大并逐渐有明显的烧结现象.

The reduction kinetic curves of FeO powder by H2 - CO mixture with different hydrogen content at 873, 973 and 1173 K were obtained through TG experiments. It was showed that the kinetic curves at 873 and 973 K are irregular due to the carbon deposition, and the kinetic curves at 1173 K keep a certain regularity with increase of hydrogen content in H2 - CO mixture. Compared the reduction kinetics by H2 - CO and H2 - Ar mixtures, the reduction rate of CO in H2 - CO mixture and CO content （ volume fraction） is basically a linear one. Morphology observation results of the samples showed that with increase of temperature, porosity of the reduction product increases, iron phase fully develops and there is an obvious sintering phenomenon happened.