Reduction of iron oxide in carbon monoxide atmosphere—reaction controlled kinetics

Mondal, Kanchan; Lorethova, Hana; Hippo, E.J.; Wiltowski, Tomasz; Lalvani, Shashi B.

doi:10.1016/j.fuproc.2003.12.009

Cited by 160 publications

(75 citation statements)

References 11 publications

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“…To explain the observed features of the scale reduction kinetics, it was assumed that, at a temperature below 1 000°C and in a pure CO atmosphere, a carbon deposition or an iron carburizing could take place as one can predict from Fe-C-O equilibrium diagram as it has already been shown by Turkdogan 15) and more recently by Mondal and et al 30) To validate this hypothesis, a reduction run at 830°C was interrupted at 0.3 of reduction fraction and the carbon content in the sample was measured by LECO CS-244 analyzer. The value measured was about 7 mass%, thus confirming the hypothesis of carbon pickup during the scale reduction at relatively low temperature and with strongly reducing gas (pure CO).…”

Section: Reduction Kinetics Of the Scale By Carbon Monoxidementioning

confidence: 99%

Characterization and Reduction Behavior of Mill Scale

et al. 2011

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This paper presents an initial part of a project devoted to the recycling of mill scale in the form of selfreducing briquettes. First chemical and morphological characteristics of mill scale were investigated and next its gaseous reduction behavior was studied by thermogravimetry. The chemical characterization showed that wustite is the major constituent of this waste matter, with small amounts of magnetite, hematite and metallic iron. The microscopic examination of the scale revealed its complex and layered microstructure with three distinct zones. The outer layer is relatively thin and porous. It is mainly composed of hematite and magnetite. The intermediate layer is made of the dense, columnar grains of wustite. The inner layer is a very porous wustite. The gaseous reduction by carbon monoxide has a topochemical character regardless of initial morphology of scale and, depending on temperature and reducing gas composition it produces a porous iron or the iron whiskers. The unreacted shrinking core model with one interface fits quite well the kinetic data and the activation energy of reduction is about 80 kJ/mol.

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Section: Reduction Kinetics Of the Scale By Carbon Monoxidementioning

confidence: 99%

Characterization and Reduction Behavior of Mill Scale

et al. 2011

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“…The formulations of kinetics equation are derived based on the model proposed by Levenspiel [9]. Although many literatures propose the models such as Mondal et al [10], Iguchi and Yokomoto [11], and Shi et al [17]; among them, Levenspiel formulates the model in more detail by considering every step which is close with reality. Figure 2 shows the visualization of shrinking core model for iron reduction.…”

Section: Reactor Modelingmentioning

confidence: 99%

“…Mondal et al [10] propose the another kinetics model for iron reduction. Here, the kinetic constants are derived based on Arrhenius equation and Cementite formation reaction was also taken into account in their model.…”

Section: Introductionmentioning

confidence: 99%

Heat and Mass Transfer in Reduction Zone of Sponge Iron Reactor

Alamsari

Torii

Trianto

et al. 2011

ISRN Mechanical Engineering

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Numerical prediction is performed on reduction zone of iron ore reactor which is a part of counter current gas-solid reactor for producing sponge iron. The aim of the present study is to investigate the effect of reduction gas composition and temperature on quality and capacity of sponge iron products through mathematical modeling arrangement and simulation. Simultaneous mass and energy balances along the reactor lead to a set of ordinary differential equation which includes kinetic equations. Kinetic equations of reduction of hematite to iron metal, methane reforming, and water gas shift reaction are taken into account in the model. Hydrogen and carbon monoxide are used as reduction gas. The equations were solved by finite element method. Prediction shows an increase in H 2 composition while an attenuation of CO produces higher metallization degree. Metallization degree is also increased with an increase in gas inlet temperature. It is found that reduction gas temperature over 973• C (1246 K) is not recommended because the formation of sticky iron will be initiated.

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“…[1][2][3][4][5] Ganguly 6) analyzed the reduction behavior of pure calcium ferrites (calcium ferrite, calcium diferrite and dicalcium ferrite) in H 2 , CO and CO-CO 2 gas mixtures. Maeda et al 7) studied the final stage of reduction of quaternary calcium ferrite with CO-CO 2 gas mixtures.…”

Section: Introductionmentioning

confidence: 99%

Isothermal Reduction Kinetics of Powdered Hematite and Calcium Ferrite with CO–N<sub>2</sub> Gas Mixtures

Ding

Xuan

et al. 2016

ISIJ Int.

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CF is regarded as the best bonding phase with superior strength and reducibility in sintering. The comparison of hematite and CF reduction process was made in this study. Isothermal reduction experiments of powdered hematite and CF in a continuous stream of 30% CO and 70% N 2 at 1 123 K, 1 173 K and 1 223 K were conducted through thermo-gravimetric analysis (TGA). Reduction rate analysis revealed that the reduction of hematite comprises three independent steps (H→M→W→I), whereas that of CF mainly comprises two steps (H→M→I). The reduction of powdered hematite and CF can be described by shrinking layer model, not shrinking core model completely. Results of the ln-ln and Sharp analysis methods indicated that the reduction of hematite included two kinetics stages, namely, plane-like mechanism and then spherulitic-type mechanism. The reduction of CF only included the plane-like mechanism stage. The model free method revealed that the activation energy of hematite and CF reduction were 5.81 kJ·mol − 1 and 46.89 kJ·mol − 1 , respectively.

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Reduction of iron oxide in carbon monoxide atmosphere—reaction controlled kinetics

Cited by 160 publications

References 11 publications

Characterization and Reduction Behavior of Mill Scale

Characterization and Reduction Behavior of Mill Scale

Heat and Mass Transfer in Reduction Zone of Sponge Iron Reactor

Isothermal Reduction Kinetics of Powdered Hematite and Calcium Ferrite with CO–N<sub>2</sub> Gas Mixtures

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