Effective induction of magnetite on suspension magnetization roasting of hematite and reaction kinetics verification

Tang, Zhidong; Liu, Xiao; Gao, Peng; Han, Yuexin; Xu, Benwei

doi:10.1016/j.apt.2022.103593

Cited by 11 publications

(3 citation statements)

References 45 publications

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“…These findings suggest that heating the magnetite phase to 100% hematite phase at 350 °C for an hour is not possible. This phenomenon is related to the minimum activation energy required to change the structure of Fe 3 O 4 to α-Fe 2 O 3 has not been fulfilled [23,25,26]. Samples H500, H650, and H800 showed peaks corresponding to the α-Fe 2 O 3 phase, with no impurity peaks.…”

Section: Resultsmentioning

confidence: 99%

Effect of calcination temperature on structure evolution of hematite nanoparticles

Husain,

Adi,

Subaer

et al. 2024

Phys. Scr.

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This research aims to examine the transition structure of iron oxide, namely from magnetite to hematite, and the impact of calcination temperature on the structural development of hematite nanoparticles. The coprecipitation process was used to extract the magnetite from Indonesian local iron sand. Magnetite was calcined at several temperatures (350, 500, 650, and 800 °C) to produce hematite. Several characterization methods were combined to investigate the structure changes due to the effect of calcination temperature. The synchrotron X-ray diffraction (SRD) and X-ray absorption spectroscopy (XAS) techniques were used to investigate the crystal and local structure, respectively. The Debye-Schrerer equation at the most dominant SRD peak were used to determine the crystallite size. Meanwhile, scanning electron microscopy (SEM) performed to studied the surface morphology. The results of SRD showed that the Fe3O4 and α-Fe2O3 phases are visible in the sample calcined at 350°C, whereas the single-phase α-Fe2O3 was seen at higher temperatures. It was also observed that the crystallinity and crystallite size increased due to the increasing calcination temperature. The crystallite size increased from 9.57 to 29.55, 16.40, 28,48, 29.26, and 29.55 nm for the magnetite, H350, H500, H650, and H800 samples. Meanwhile, XAS fitting data found that higher calcination temperatures increase the interatomic distance but decrease the Debye-Waller factor. It can be concluded that the transformation from Fe3O4 to single-phase α-Fe2O3 was observed at 500oC. A higher calcination temperature of at least 800oC wouldn't change the phase but affect the structure parameters.

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Section: Resultsmentioning

confidence: 99%

Effect of calcination temperature on structure evolution of hematite nanoparticles

Husain,

Adi,

Subaer

et al. 2024

Phys. Scr.

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“…The above experiments and analyses demonstrated that the conversion of hematite to magnetite could be significantly inhibited by the addition of NaOH during the suspension reduction process, while the essential inhibition mechanism of NaOH on the reduction of hematite was still unclear. Herein, thermodynamic analysis and SEM-EDS detec- Fe3O4(s) + CO(g) = 3FeO(s) + CO2(g) (11) Fe3O4(s) + 4CO(g) = 3Fe(s) + 4CO2(g) (12) FeO(s) + CO(g) = Fe(s) + CO2(g) (13) 2NaOH(s) + Fe2O3(s) = Na2O•Fe2O3(s) + H2O(g) (14) 3Na2O•Fe2O3(s) + CO(g) = 2Fe3O4(s) + 3Na2O(s) + CO2 further hinder the reduction of hematite in the interior. Number Equation (9) 3Fe2O3(s) + CO(g) = 2Fe3O4(s) + CO2(g) (10) Fe3O4(s) + CO(g) = 3FeO(s) + CO2(g) (11) Fe3O4(s) + 4CO(g) = 3Fe(s) + 4CO2(g) (12) FeO(s) + CO(g) = Fe(s) + CO2(g) (13) 2NaOH(s) + Fe2O3(s) = Na2O•Fe2O3(s) + H2O(g) (14) 3Na2O•Fe2O3(s) + CO(g) = 2Fe3O4(s) + 3Na2O(s) + CO2(g)…”

Section: Inhibited Reduction Mechanism Analysismentioning

confidence: 99%

“…In the last few decades, plenty of studies have been conducted to investigate the most efficient method of extracting iron from red mud. Among them, suspension magnetization roasting (SMR) developed by the Han research tem (Northeastern University) is regarded as a potentially efficient method to treat refractory iron ore due to its low roasting temperatures, high quality, high energy utilization and lower pollution [12][13][14][15][16]. Liu et al [17] studied the effect of SMR operation parameters on the recovery of iron from red mud in a laboratory, and it was found that a good indicator with iron recovery of 88.45% and iron grade of 56.41% was acquired under the optimized conditions of 540 • C roasting temperature, 15 min reduction time, 500 mL/min gas flow rate and 30% CO concentration.…”

Section: Introductionmentioning

confidence: 99%

Effects of NaOH Content on the Reduction Kinetics of Hematite by Using Suspension Magnetization Roasting Technology

Yuan

Wang

et al. 2022

Minerals

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Red mud is a potential iron resource that needs to be urgently exploited and utilized. However, due to the properties of high alkalinity, fine particle size and complex mineral composition, the utilization of red mud is difficult. Focusing on red mud’s prominent feature of high alkalinity, this paper studies the influence of NaOH content on the reduction kinetics of hematite, which is the main component of red mud. The results show that the conversion degree of hematite was strongly inhibited by NaOH, and the magnetization and specific magnetic susceptibility of reduction products was significantly decreased with the increase in NaOH content. Meanwhile, the results of the calculation of kinetics parameters demonstrate that the addition of NaOH did not affect the control step of the reduction of hematite, while it dramatically decreased the reduction rate of hematite. Moreover, thermodynamic analysis and SEM-EDS detection were conducted to uncover the inhibited mechanism of NaOH on the reduction of hematite, which indicated that sodium ferrite could be produced spontaneously under the experimental conditions and that it is hard for it to be further reduced by CO. Furthermore, the produced sodium ferrite formed a dense film, which covered the surface of the hematite particles, inhibiting the diffusion of CO and thereby hindering the reduction of the interior hematite.

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An innovative study for pretreatment of high-phosphorus oolitic hematite via high-temperature heating: phase, microstructure, and phosphorus distribution analyses

Liu

Han

et al. 2023

Advanced Powder Technology

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Effective induction of magnetite on suspension magnetization roasting of hematite and reaction kinetics verification

Cited by 11 publications

References 45 publications

Effect of calcination temperature on structure evolution of hematite nanoparticles

Effect of calcination temperature on structure evolution of hematite nanoparticles

Effects of NaOH Content on the Reduction Kinetics of Hematite by Using Suspension Magnetization Roasting Technology

An innovative study for pretreatment of high-phosphorus oolitic hematite via high-temperature heating: phase, microstructure, and phosphorus distribution analyses

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