The reduction kinetics of hematite particles in H2 and CO atmospheres

Oh, Jeongseog; Noh, Dong-Soon

doi:10.1016/j.fuel.2016.10.125

Cited by 95 publications

(33 citation statements)

References 26 publications

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“…These reactors include fluidized bed reactors, packed bed reactors, and thermogravimetric analyzers (TGAs). 4) Iron ore pellet reduction has been investigated in numerous studies in recent decades. Previous research found…”

Section: Introductionmentioning

confidence: 99%

Influence of H2–H2O Content on the Reduction of Acid Iron Ore Pellets in a CO–CO2–N2 Reducing Atmosphere

et al. 2020

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Using hydrogen as a reducing agent for iron production has been the focus of several studies due to its environmental potential. The aim of this work is to study the influence of H 2-H 2 O content in the gas phase on the reduction of acid iron ore pellets under simulated blast furnace conditions. Temperature and gas compositions for the experiments were determined with multi-point vertical probes in an industrial blast furnace. The results of the reduction tests show that higher temperatures and H 2 content increase the rate and extent of reduction. For all the gas and temperature combinations, morphological, mineralogical, and microstructure changes were observed using different characterization techniques. Microscopy images reveal that H 2-H 2 O, in the gas phase, has a positive influence on reduction, with metallic iron forming at the pellet's periphery and core at lower temperatures compared to CO-CO 2-N 2 reducing gas. Porosity and surface area changes were determined using a gas pycnometer and the BET method. The results indicate that increasing the reduction temperatures and H 2 content results in greater porosity and a larger surface area. Moreover, carbon deposition did not take place, even at lower temperatures. A rate minimum was detected for pellets reduced at 800°C, probably due to metallic iron formation, hindering the diffusion of reducing gases through the product iron layer.

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Section: Introductionmentioning

confidence: 99%

Influence of H2–H2O Content on the Reduction of Acid Iron Ore Pellets in a CO–CO2–N2 Reducing Atmosphere

et al. 2020

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“…The iron oxide obtained can be used as a raw material in the ironmaking sectors. Many recent reports are available on the reduction of iron-oxide-bearing materials from various known agents [8][9][10][11][12][13][14][15][16].…”

Section: Introductionmentioning

confidence: 99%

Thermal Behavior of Hydrated Iron Sulfate in Various Atmospheres

Kanari

Ménad

Ostrosi

et al. 2018

Metals

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Iron sulfate, in particular FeSO4·7H2O, is derived from titanium dioxide production and the steel pickling process. Regarding TiO2 manufacturing, the amount of the resultant FeSO4·7H2O can be as high as 6 tons per ton of produced TiO2, leading to a huge amount of ferrous sulfate heptahydrate, which is considered an environmental and economic concern for the titanium dioxide industry in European countries. The present paper focuses on the thermal treatment of ferrous sulfate (heptahydrate and monohydrate) samples under different conditions. Nonisothermal thermogravimetric (TG) analysis was used to study the behavior of iron sulfate samples at temperatures of up to 1000 °C in Cl2 + O2, O2, and N2 atmospheres. Results showed that the dehydration of iron sulfate heptahydrate in nitrogen started at room temperature and resulted in iron sulfate tetrahydrate (FeSO4·4H2O). The ferrous sulfate monohydrate (FeSO4·H2O) was formed at temperatures close to 150 °C, while the anhydrous ferrous sulfate (FeSO4) was obtained when the samples were heated in nitrogen at over 225 °C. The kinetic features of FeSO4 decomposition into Fe2O3 were revealed under isothermal conditions at temperatures ranging from 500 to 575 °C. The decomposition of iron sulfate was characterized by an apparent activation energy of around 250 kJ/mol, indicating a significant temperature effect on the decomposition process. The obtained powder iron oxide could be directed to the agglomeration unit of iron and the steelmaking process.

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“…For instance, the reduction of iron ores in the upper part of blast furnace, the gas-based reduction of ores in the shaft furnace, the reduction of molybdenum oxides, manganese ores, nickel oxides or other metals oxides by carbonaceous reducing agents, all of these reductions are involved in the CO reaction. [1][2][3][4][5][6][7] Moreover, with the increase of environmental protection requirements for iron and steel production, 8) the CO reduction attracts the extensive attention and needs to be further studied.…”

Section: Introductionmentioning

confidence: 99%

“…A number of valuable kinetic models which describe the gassolid reaction have been proposed in literatures, such as the nucleation and growth model, [9][10][11] Fruehan's model, 12) the sharp interface model, [13][14][15] the volume reaction model. [16][17][18] Rao's group 19,20) have investigated the intrinsic rate of reduction metallic oxides and examined the influence of pore diffusion of gaseous species on the shape of the growing nucleus, and modeled the reduction of hematite with CO 2 and CO gases as the reacting intermediates. Tien and Turkdogan 21) reported a mathematical analysis of gaseous reduction of iron oxides with considering the partial internal reduction of the porous oxide and gas diffusion in the porous iron layer.…”

Section: Introductionmentioning

confidence: 99%

A Model for the Reduction of Metal Oxides by Carbon Monoxide

Dang

Chou

2018

ISIJ International

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The reduction of metal oxides by carbon monoxide is a very significant reaction in metallurgical and chemical industries. In current study, a kinetic model describing the reduction reaction of metal oxides by CO has been developed. The model is in the analytic function of parameters such as temperature, radius of the particle, CO content, density of metal oxides and time, which is, therefore, convenient for usage and theoretical analysis. The developed model can be applied to describe the reduction kinetics of metal oxides under both isothermal and non-isothermal conditions. Particularly, it can be used to describe the kinetics of both single reduction reaction (single reaction interface) and dual reduction reactions (double reaction interfaces, such as, the reduction of Fe 2 O 3 to FeO with Fe 3 O 4 being the intermediate product) as well. Application of the developed model to practical systems validated that its predicted values agreed very well with the experimental data in literatures.

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The reduction kinetics of hematite particles in H2 and CO atmospheres

Cited by 95 publications

References 26 publications

Influence of H<sub>2</sub>–H<sub>2</sub>O Content on the Reduction of Acid Iron Ore Pellets in a CO–CO<sub>2</sub>–N<sub>2</sub> Reducing Atmosphere

Influence of H<sub>2</sub>–H<sub>2</sub>O Content on the Reduction of Acid Iron Ore Pellets in a CO–CO<sub>2</sub>–N<sub>2</sub> Reducing Atmosphere

Thermal Behavior of Hydrated Iron Sulfate in Various Atmospheres

A Model for the Reduction of Metal Oxides by Carbon Monoxide

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