Isothermal and Non-Isothermal Reduction Behaviors of Iron Ore Compacts in Pure Hydrogen Atmosphere and Kinetic Analysis
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Isothermal and Non-Isothermal Reduction Behaviors of Iron Ore Compacts in Pure Hydrogen Atmosphere and Kinetic Analysis Abourehab Hammam 1,2 & Ying Li 1 & Hao Nie 1 & Lei Zan 1 & Weitian Ding 1 & Yao Ge 1 & Meng Li 1 & Mamdouh Omran 1,2,3 & Yaowei Yu 1 Received: 18 March 2020 / Accepted: 21 September 2020 # The Author(s) 2020
Abstract This study examines the isothermal and non-isothermal reduction behaviors of iron ore compacts in a pure hydrogen atmosphere and compares the results obtained during the reduction process by CO. The different phases accompanying the reduction reactions were identified using X-ray diffraction (XRD) and its morphology was microscopically examined. In isothermal experiments, temperature plays a significant role in the reduction process. At any given temperature, the reduction rate during the initial stages is higher than that during the final stages. The reduction rate in H2 atmosphere was faster than in CO gas. The comparison of activation energy values suggested that reduction with H2 is more efficient than with CO. At the same temperature, the time required to achieve a certain degree of reduction was lower when using H2 gas than CO atmosphere. In non-isothermal tests, the heating rate has a significant effect on the reduction rate and reduction extent. At the same heating rate, the degree of reduction was higher in H2 atmosphere than in CO gas. Based on experimental data, the parameters of reaction kinetics were deduced by application of model-free and model-fitting methods. The reduction in H2 atmosphere was controlled by nucleation model (Avrami-Erofeev model), while the CO reduction reaction was controlled by gas diffusion. Keywords Hydrogen gas . Isothermal reduction . Non-isothermal reduction . Kinetics and mechanism
1 Introduction Iron and steelmaking sector is one of the most important sectors due its great impact on the global growth, economy, and development. In recent years, the steel production rate has increased sharply [1]. By 2050, steel demand is expected to increase to 1.5 times higher than the current levels in order to meet the needs of a growing population [2, 3]. About 70% of the total steel production relies directly on inputs from coke and coal [3, 4]. The CO2 emission from iron and steelmaking
* Mamdouh Omran [email protected] * Yaowei Yu [email protected] 1
State Key Laboratory of Advanced Special Steel, Shanghai Key Laboratory of Advanced Ferrometallurgy, School of Materials Science and Engineering, Shanghai University, Shanghai, China
2
Central Metallurgical Research and Development Institute (CMRDI), P.O. Box 87, -Helwan, Cairo, Egypt
3
Process Metallurgy Research Group, Faculty of Technology, University of Oulu, Oulu, Finland
was 2.3 billion tons in 2007, while by 2050 it is expected to reach 3.0 billion tons [5]. Nowadays, the main challenges for the steel industry are energy consumption and environmental pollution. Therefore, the growing of the steel sector requires serious attention in order to establish processes that are economically vi
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