Phase transformation and reduction kinetics during the hydrogen reduction of ilmenite concentrate

• Published in: International journal of minerals, metallurgy and materials Vol. 19; no. 5; pp. 384 - 390
• Main Authors: Si, Xin-guo, Lu, Xiong-gang, Li, Chuan-wei, Li, Chong-he, Ding, Wei-zhong
• Format: Journal Article
• Language: English
• Published: Springer Berlin Heidelberg University of Science and Technology Beijing 01.05.2012; Springer Nature B.V; Hebei Iron and Steel Group Tangshan Steel Company, Tangshan 063020, China%Shanghai Key Laboratory of Modern Metallurgy and Materials Processing, Shanghai University, Shanghai 200072, China; Shanghai Key Laboratory of Modern Metallurgy and Materials Processing, Shanghai University, Shanghai 200072, China
• Subjects: Ceramics; Characterization and Evaluation of Materials; Chemistry and Materials Science; Composites; Corrosion and Coatings; Cracks; Diffusion rate; Glass; Hydrogen reduction; Ilmenite; Iron; Iron constituents; Kinetics; Light microscopy; Materials Science; Metallic Materials; Metallizing; Microstructure; Natural Materials; Optical microscopy; Phase transformations; Phase transitions; Process control; Reduction; Scanning electron microscopy; Solid solutions; Surfaces and Interfaces; Thin Films; Titanium oxides; Tribology; Weight loss; X-ray diffraction; 反应时间; 扫描电子显微镜; 氢还原; 相变; 还原动力学; 速率控制步骤; 金属化率; 钛铁精矿; ilmenite; metallization; phase transformations; hydrogen; kinetics; reduction
• ISSN: 1674-4799; 1869-103X
• DOI: 10.1007/s12613-012-0568-4

The reduction of ilmenite concentrate by hydrogen gas was investigated in the temperature range of 500 to 1200℃. The microstructure and phase transition of the reduction products were studied by X-ray diffraction （XRD）, scanning electron microscopy （SEM）, and optical microscopy （OM）. It was found that the weight loss and iron metallization rate increased with the increase of reduction temperature and reaction time. The iron metallization rate could reach 87.5% when the sample was reduced at 1150℃ for 80 min. The final phase constituents mainly consist of Fe, M305 solid solution phase （M=Mg, Ti, and Fe）, and few titanium oxide. Microstructure analysis shows that the surfaces of the reduction products have many holes and cracks and the reactions take place from the exterior of the grain to its interior. The kinetics of reduction indicates that the rate-controlling step is diffusion process control with the activation energy of 89 kJ.mo1-1.