Reduction Rates for the Mixture of Iron Oxide and Zinc Oxide, and ZnFe_2O_4 with CO-CO_2 Gas Mixtures

氧化铁和氧化锌的混合物以及ZnFe_2O_4与CO-CO_2气体混合物的还原率

• 批准号: 01550516
• 负责人: ITOH Satoshi
• 金额: $ 1.34万
• 依托单位: Tohoku University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for General Scientific Research (C)
• 财政年份: 1989
• 资助国家: 日本
• 起止时间: 1989 至 1991
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-01550516/
• 关键词: Reduction Kinetics; Mixture of Iron Oxide and Zinc Oxide; Zinc Ferrite; Multi-Interface Unreacted Core Model; Effective Diffusivity; Reaction Rate Constant; Rate-Determining Step; Iron-Reduction Distillation Process; 混合律速; ヘマタイトの還元反応速度; 酸化亜鉛の還元反

In order to analyze the reduction rates for the mixture of iron oxide and zinc oxide, and ZnFe_2O_4 with CO-CO_2 gas mixtures, first of all reduction experiments were carried out in pure hematite pellet and pure zinc oxide pellet in the temperature range from 973 to 1173 K. Experimental data for each reduction were analyzed in terms of the mixed-control kinetics based on the unreacted core model and the shrinking model, respectively. Then experimental data for both the reductions of the mixture of iron oxide and zinc oxide, and ZnFe_2O_4 were analyzed in terms of the mixed control kinetics based on the two-interface model, in which activities of ZnO and FeO were taken into account. The results are summarized as follows :1. For hematite pellets the calculated reduction curves by using the reaction rate constant and the effective diffusivity are in satisfactory agreement with the experimental data.2. For zinc oxide pellets the calculated reduction curves by using the reaction rate constant finely reproduced the experimental data. And it was found that the overall rate is controlled by chemical reaction under the experimental conditions.3. For both the mixture of iron oxide and zinc oxide, and ZnFe_2O_4 the calculated reduction curves by using the rate parameters and activities of ZnO and FeO are in satisfactory agreement with the experimental data, except the reduction curve of zinc oxide on the experimental condition of 1173 K, 92.0%CO on which the experimental data of zinc oxide exhibited delay as compared with the calculated reduction curves.4. It was found from experimental results and calculations based on the two-interface model that the most suitable condition for the first reduction stage of the iron-reduction distillation process was the rather low temperature such as about 973 K.

为了分析氧化铁和氧化锌的混合物以及ZnFe_2O_4与CO-CO_2气体混合物的还原率，首先在973~1173 K的温度范围内对纯赤铁矿球团和纯氧化锌球团进行还原实验。基于未反应的核心，对每次还原的实验数据进行混合控制动力学分析。 分别为模型和收缩模型。然后根据基于双界面模型的混合控制动力学分析了氧化铁和氧化锌混合物以及ZnFe_2O_4的还原实验数据，其中考虑了ZnO和FeO的活性。研究结果如下： 1．对于赤铁矿球团，利用反应速率常数和有效扩散率计算的还原曲线与实验数据吻合较好。 2．对于氧化锌颗粒，通过使用反应速率常数计算的还原曲线很好地再现了实验数据。实验结果表明，在实验条件下，总体速率受化学反应控制。 3．对于氧化铁和氧化锌的混合物以及ZnFe_2O_4，利用ZnO和FeO的速率参数和活度计算的还原曲线与实验数据吻合良好，只是在1173 K、92.0%CO的实验条件下氧化锌的还原曲线与计算的还原曲线相比，氧化锌的实验数据表现出延迟。 4．根据双界面模型的实验结果和计算发现，铁还原精馏过程第一阶段还原的最合适条件是较低的温度，如973 K左右。