Print Email Facebook Twitter Reduction Mechanism of Fine Hematite Ore Particles in Suspension Title Reduction Mechanism of Fine Hematite Ore Particles in Suspension Author Chen, Z. (TU Delft (OLD) MSE-3; Flemish Institute for Technological Research) Zeilstra, Christiaan (Tata Steel) van der Stel, Jan (Tata Steel) Sietsma, J. (TU Delft Team Kevin Rossi) Yang, Y. (TU Delft Team Yongxiang Yang) Date 2021 Abstract In order to understand the pre-reduction behaviour of fine hematite particles in the HIsarna process, change of morphology, phase and crystallography during the reduction were investigated in the high temperature drop tube furnace. Polycrystalline magnetite shell formed within 200 ms during the reduction. The grain size of the magnetite is in the order of magnitude of 10 µm. Lath magnetite was observed in the partly reduced samples. The grain boundary of magnetite was reduced to molten FeO firstly, and then the particle turned to be a droplet. The Johnson-Mehl-Avrami-Kolmogorov model is proposed to describe the kinetics of the reduction process. Both bulk and surface nucleation occurred during the reduction, which leads to the effect of size on the reduction rate in the nucleation and growth process. As a result, the reduction rate constant of hematite particles increases with the increasing particle size until 85 µm. It then decreases with a reciprocal relationship of the particle size above 85 µm. To reference this document use: http://resolver.tudelft.nl/uuid:de3c2151-673d-488a-8772-7e3a142bee4b DOI https://doi.org/10.1007/s11663-021-02173-y ISSN 1073-5615 Source Metallurgical and Materials Transactions B - Process Metallurgy and Materials Processing Science, 52 (4), 2239-2252 Part of collection Institutional Repository Document type journal article Rights © 2021 Z. Chen, Christiaan Zeilstra, Jan van der Stel, J. Sietsma, Y. Yang Files PDF Chen2021_Article_Reductio ... Hemati.pdf 3.41 MB Close viewer /islandora/object/uuid:de3c2151-673d-488a-8772-7e3a142bee4b/datastream/OBJ/view