Industrial fluidised bed direct reduction kinetics of hematite ore fines in H2 rich gases at elevated pressure

Weiss, Brandon; Sturn, J.; Voglsam, S.; Winter, Franz; Schenk, Johannes

doi:10.1016/j.ces.2010.11.024

Cited by 24 publications

(3 citation statements)

References 16 publications

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“…The reduction of Fe 2 O 3 with hydrogen and CO has been the subject of much research. ,,,, Thermodynamic calculations show that the Fe 2 O 3 → Fe 3 O 4 transformation occurs easily in gas mixtures with a low reducing potential over a wide temperature range. The further reduction of Fe 3 O 4 to metallic iron is a combination of two single-step reactions, Fe 3 O 4 → FeO and FeO → Fe, that may proceed in parallel .…”

Section: Resultsmentioning

confidence: 99%

The Influence of Cu and Al Additives on Reduction of Iron(III) Oxide: In Situ XRD and XANES Study

et al. 2019

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The reduction of Fe-based nanocomposite catalysts doped with Al and Cu has been studied using in situ X-ray diffraction (XRD), in situ X-ray absorption near-edge structure (XANES), and temperature-programmed reduction (TPR) techniques. The catalysts have been synthesized by melting of iron, aluminum, and copper salts. According to XRD, the catalysts consist mainly of Fe2O3 and Al2O3 phases. Alumina is in an amorphous state, whereas iron oxide forms nanoparticles with the protohematite structure. The Al3+ cations are partially dissolved in the Fe2O3 lattice. Due to strong alumina–iron oxide interaction, the specific surface area of the catalysts increases significantly. TPR and XANES data indicate that copper forms highly dispersed surface CuO nanoparticles and partially dissolves in iron oxide. It has been shown that the reduction of iron(III) oxide by CO proceeds via two routes: a direct two-stage reduction of iron(III) oxide to metal (Fe2O3 → Fe3O4 → Fe) or an indirect three-stage reduction with the formation of FeO intermediate phases (Fe2O3 → Fe3O4 → FeO → Fe). The introduction of Al into Fe2O3 leads to a decrease in the rate for all reduction steps. In addition, the introduction of Al stabilizes small Fe3O4 particles and prevents further sintering of the iron oxide. The mechanism of stabilization is associated with the formation of Fe3–x Al x O4 solid solution. The addition of copper to the Fe–Al catalyst leads to the formation of highly dispersed CuO particles on the catalyst surface and a mixed oxide with a spinel-type crystalline structure similar to that of CuFe2O4. The low-temperature reduction of Cu2+ to Cu0 accelerates the Fe2O3 → Fe3O4 and FeO → Fe transformations but does not affect the Fe3O4 → FeO/Fe stages. These changes in the reduction properties significantly affect the catalytic performance of the Fe-based nanocomposite catalysts in the low-temperature oxidation of CO.

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Section: Resultsmentioning

confidence: 99%

The Influence of Cu and Al Additives on Reduction of Iron(III) Oxide: In Situ XRD and XANES Study

et al. 2019

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“…And it has been observed in practice especially for fine iron oxide particles. [18][19][20][21] Hence, it is assumed that the mass transfer resistance of gases from the bulk to the surface can be neglected. Thurnhofer 18) conducted microscopical analyses of polished sections of reduced iron ore fines and observed that a high amount of pores were spread through the entire fine.…”

Section: )mentioning

confidence: 99%

“…Weiss 21) described the reduction kinetics of iron ore fines with a chemical reaction control scheme using the unreacted shrink core model though forms of their reduction rate equations were different. In this work, it is also assumed that the reduction of ore fines proceeds following the unreacted shrinking core model.…”

Section: )mentioning

confidence: 99%

Simulation Study on Performance of Z-path Moving-fluidized Bed for Gaseous Reduction of Iron Ore Fines

2012

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Performance of the Z-path moving-fluidized bed reactor for gaseous reduction of iron ore fines was numerically investigated. The proposed mathematical model was developed by analyzing the gas-solid transport phenomena and chemical reactions in the reactor. The model was solved by a new solving approach -integration of FLUENT package (V6.3) and PHOENICS (V3.3). Numerical simulation results of cold state were compared with the experimental data and the simulation results including pressure drop per perforated plate, gas flow pattern and solid flow pattern agreed well with the experimental ones. The developed CFD model then conducted some hot state predictions of gaseous reduction of iron ore fines using reformed COG gas and purified COREX export gas in this reactor. Results indicate that under hot state, the performance of the reactor depends on the reducing gas supplied. Pressure drop per perforated plate decreases one by one from the bottom plate to the top plate and some improvements are needed for the perforated plate arrangement in the reactor. For ore fines gaseous reduction, the reactor displays a high utilization efficiency of gas sensible heat and gas reduction potential. The Z-path moving fluidized bed has the advantage that it realizes a gradient utilization of heat and reduction potential of the gas in iron ore fines reduction with a comparatively simple structure. In the cases simulated, the top two plates play a role of preheating the ore fines and the bottom three plates reducing the ore fines. For operation control, the reactor with three inclined perforated plates is reasonable and preheating ore fine may be carried out by other means.

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Multistep Reduction Kinetics of Fine Iron Ore with Carbon Monoxide in a Micro Fluidized Bed Reaction Analyzer

Chen

Zheng

Chen

et al. 2017

Metall Mater Trans B

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Industrial fluidised bed direct reduction kinetics of hematite ore fines in H2 rich gases at elevated pressure

Cited by 24 publications

References 16 publications

The Influence of Cu and Al Additives on Reduction of Iron(III) Oxide: In Situ XRD and XANES Study

The Influence of Cu and Al Additives on Reduction of Iron(III) Oxide: In Situ XRD and XANES Study

Simulation Study on Performance of Z-path Moving-fluidized Bed for Gaseous Reduction of Iron Ore Fines

Multistep Reduction Kinetics of Fine Iron Ore with Carbon Monoxide in a Micro Fluidized Bed Reaction Analyzer

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