Reduction behavior of hematite ore with different particle sizes in suspension roaster

High-purity hematite was divided into five size fractions, and the reduction behavior of these fractions was investigated to explore the problem of the asynchronous reaction of heterogeneous and complex refractory iron ore. The quantitative relationship between the conversion rate, roasting time, and ore par-ticle size of different temperature systems was determined using the MATLAB software. X-ray diffraction (XRD) and vibrating sample magnetometry (VSM) were conducted on roasted samples, and reducing the ore size was found to promote the transformation of the hematite phase into magnetite during the mag-netization roasting process. Scanning electron microscopy (SEM) and specific surface area analysis demonstrated that the new magnetite had a loose porous structure, which provides a channel for CO gas to contact with the new hematite surface. The increase in the ore particle size increased the CO dif-fusion resistance, resulting in an asynchronous reaction.(c) 2022 Published by Elsevier B.V. on behalf of The Society of Powder Technology Japan.

Automated summary

The reduction behavior of different size fractions of high-purity hematite was investigated to address the asynchronous reaction issue in heterogeneous and complex refractory iron ore. The results indicated that reducing the ore size promoted the transformation from hematite to magnetite, with the newly formed magnetite exhibiting a loose porous structure. This structure facilitated the contact between CO gas and the new hematite surface. However, an increase in ore particle size increased CO diffusion resistance, resulting in an asynchronous reaction.