Related Experiment Video
Updated: Sep 11, 2025

Methods of Ex Situ and In Situ Investigations of Structural Transformations: The Case of Crystallization of Metallic Glasses
Published on: June 7, 2018
Phase Transformation Principle and Magnetite Grain Growth Law in the Magnetization Sintering Process of Oolitic
Hanquan Zhang1, Xunrui Liu1, Lei Xie1
1School of Resources & Safety Engineering, Wuhan Institute of Technology, Wuhan 430074, China.
Abstract:
Oolitic hematite ore represents a significant iron resource, but its utilization is challenging due to the complex multi-layered circular structure of hematite ore, which makes it difficult to be reduced. This study systematically investigated the phase transformation principle and magnetite grain growth law during the magnetization sintering of oolitic hematite ore, aiming to establish optimal conditions for efficient hematite ore to magnetite conversion. The results demonstrated that both elevated temperature and prolonged reduction duration significantly enhanced the reduction efficiency of hematite (Fe2O3) to magnetite. The optimal sintering conditions were determined to be 700 °C for 45 min, under which the magnetite content and Fe/O atomic ratio in the roasted products peaked at approximately 68% and 0.8%, respectively. However, temperatures exceeding 800 °C proved detrimental to magnetite formation, as further reduction to FeXO phases occurred. Notably, appropriate temperature elevation promoted substantial magnetite grain growth. When the sintering temperature increased from 600 °C to 700 °C, both the absolute and relative thickness of the magnetite layer exhibited remarkable enhancement, expanding from 9.52 μm to 76.76 μm and from 5.99% to 50.33%, respectively. Furthermore, comparative analysis revealed that a high sintering temperature for a short time was more effective for magnetite particle growth than a low temperature for a long time in the magnetization process of oolitic hematite ore.
More Related Videos
Related Concept Videos
Ferromagnetism
Steel Manufacturing
During this smelting process, limestone plays a crucial role by forming slag. Slag captures impurities within the molten iron, such...
Phase Diagram
Magnetism
An individual magnetic pole cannot be isolated. No matter how small, every piece of a magnet contains a north pole and a south...
Precipitation Processes

