Effect of Preoxidation Temperature on the Reduction Kinetics of Ilmenite Concentrate

Choi, Kyungsob; Park, Hyun-Sik

doi:10.1007/s11837-022-05480-0

Cited by 4 publications

(2 citation statements)

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“…The rate of reduction reaction of ilmenite that has been preoxidized at 1000 °C is much higher compared to ilmenite preoxidized at 600 and 800 °C. Choi and Park 13 studied the reduction reaction of 600−1000 °C preoxidized ilmenite at 1000 °C with a reduction gas of 50% H 2 + 50% CO. Ilmenite oxidized at low temperatures (600− 800 °C) exhibited a more rapid reduction rate compared to that which was oxidized at high temperatures (900−1000 °C). Zhang et al 14 conducted a comparison between the hydrogen reduction of untreated ilmenite and ilmenite that had been preoxidized at low temperature (780 °C) and high temperature (900 °C).…”

Section: Introductionmentioning

confidence: 99%

“…Compared to the untreated ilmenite, the preoxidized ilmenite exhibited a decrease of approximately 25% in the average activation energy, along with a 67 °C lower starting reduction temperature. At a reduction temperature of 1000 °C, Choi and Park 13 investigated the reduction kinetics of ilmenite oxidized at 600−1000 °C in a 50% H 2 + 50% CO environment. Ilmenite samples oxidized at 600 and 1000 °C had activation energies of 44.31 and 101.55 kJ/mol, respectively, for reduction.…”

Section: Introductionmentioning

confidence: 99%

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Influence of Preoxidation Treatment on the Reduction Behavior and Reaction Kinetics of Vanadium Titanomagnetite by Hydrogen

Shi,

Xu,

et al. 2024

J. Phys. Chem. C

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Hydrogen is a potential alternative reducing agent, which can greatly reduce CO 2 emission in the ironmaking process of vanadium titanomagnetite. This paper investigated the reaction process and kinetic characteristics of the hydrogen reduction of both untreated and preoxidized vanadium titanomagnetite using a thermogravimetric analyzer (TG). The effects of different preoxidation temperatures (T oxi = 500 °C, T oxi = 700 °C, and T oxi = 900 °C) on the reduction characteristics of vanadium titanomagnetite were compared at a reduction temperature of 1000 °C. It was found that the reduction degree and reduction rate of low-temperature (T oxi = 500 °C and T oxi = 700 °C) preoxidized vanadium titanomagnetite are higher than those of high-temperature (T oxi = 900 °C) preoxidized vanadium titanomagnetite. X-ray diffraction (XRD) and scanning electron microscopy (SEM) analyses show that the low-temperature preoxidation process separates the Fe/Ti in vanadium titanomagnetite and forms micropores on the surface of the vanadium titanomagnetite, while the high-temperature preoxidation process allows the separated hematite and ilmenite to recombine and form pseudobrookite. The isothermal reduction experiments on untreated and preoxidized vanadium titanomagnetite were carried out, with reduction temperatures ranging from 600 to 1000 °C. The obtained results were subjected to kinetic analysis using conventional model-fitting and iso-conversional methods. The fitting results of different kinetic models show that the activation energies of the preoxidized vanadium titanomagnetite reduction reaction are lower than those of untreated vanadium titanomagnetite. In the entire range of the reduction reaction, the contracting area model (R 2 ) can best describe the reaction between hydrogen and untreated and preoxidized vanadium titanomagnetite. After the preoxidized treatment, the reduction energy barrier of vanadium titanomagnetite decreases by about 38.0%.

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Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%