Role of MgO in Sinter from Perspective of MgO Distribution between Liquid and Magnetite Phases in FeO&lt;sub&gt;x&lt;/sub&gt;–CaO–SiO&lt;sub&gt;2&lt;/sub&gt;–MgO System

Hayashi, Miyuki; Tanaka, Hiroki; Watanabe, Takashi; Susa, Masahiro

doi:10.2355/isijinternational.isijint-2017-305

Cited by 7 publications

(6 citation statements)

References 19 publications

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“…An increase in the amount of dissolving CaO with increasing basicity has been reported. 21,23) Thus, the high dissolution of CaO in magnetite found in the low-slag sintered ores in this study is mostly due to the prevention of the reaction of MgO by using brucite and the increasing basicity of fine particles by selective granulation.…”

Section: Microstructure Of Low-slag High-feo Sinteredmentioning

confidence: 77%

“…Many investigations have reported a decrease in melt during sintering by MgO addition. 19,[21][22][23] Therefore, the improvement of sinter quality is mostly caused by the improvement of melt quantity and properties due to the low reactivity of brucite preventing MgO dissolution into the CF melt.…”

Section: Changes In Sintering Performance and Quality Ofmentioning

confidence: 99%

“…MgO is widely distributed in magnetite. 19,21,[23][24][25] Figure 11 shows the measurement results of dissolving CaO and MgO in magnetite in the low-slag sintered ores in the current study. The results of past investigations of pot sinter, 1,21,24) plant sinter, 24,25) and synthesized slag 23) are also shown in the figure . There was a tendency whereby the lower the dissolution of MgO, the higher was the dissolution of CaO.…”

Section: Microstructure Of Low-slag High-feo Sinteredmentioning

confidence: 99%

“…19,21,[23][24][25] Figure 11 shows the measurement results of dissolving CaO and MgO in magnetite in the low-slag sintered ores in the current study. The results of past investigations of pot sinter, 1,21,24) plant sinter, 24,25) and synthesized slag 23) are also shown in the figure . There was a tendency whereby the lower the dissolution of MgO, the higher was the dissolution of CaO. This ten-dency is mostly due to a competitive relationship between Mg 2 + and Ca 2 + during cation replacement in the spinel structure of magnetite.…”

Section: Microstructure Of Low-slag High-feo Sinteredmentioning

confidence: 99%

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Reducing Slag Volume at Cohesive Zone of Blast Furnace by using Low-slag Sintered Ore with Reducible Magnetite

et al. 2022

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Lowering the reducing agent rate (RAR) of blast furnaces (BFs) is an effective way to mitigate CO 2 emissions in the steel industry. It is well known that low-slag sintered ores can be effective at lowering the RAR. Therefore, in this study, we focused on the manufacturing technologies of low-slag high-FeO sintered ores. High-temperature sintering was used to maintain enough strength before and during the reduction, resulting in the chemical composition of sintered ores with a T.Fe above 60 mass% and an FeO content above 8 mass%. Improvement in the permeability of the sintering bed and the melt properties were the main challenges. Stand-support sintering, selective granulation, and binder use are essential for improving the permeability. The use of brucite and reducing the Al 2 O 3 content of ores while designing their penetration length are essential for improving the melt properties as well. We implemented all of these measures in plant trials, and low-slag high-FeO sintered ores were successfully manufactured. The sintered ores exhibited a low slag volume in the cohesive zone, resulting in a lower RAR of the BF both in the offline simulator and actual plant operation. The sintered ores differed from other low-slag sintered ores manufactured previously in two aspects; large numbers of both small-sized magnetite grains and voids between grains. The reducibility of magnetite was superior to that of hematite with CaO doping, whereas MgO doping had the opposite effect. These behaviors of magnetite may explain the high reducibility of the manufactured low-slag high-FeO sintered ores.

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Section: Microstructure Of Low-slag High-feo Sinteredmentioning

confidence: 77%

Section: Changes In Sintering Performance and Quality Ofmentioning

confidence: 99%

Section: Microstructure Of Low-slag High-feo Sinteredmentioning

confidence: 99%

Section: Microstructure Of Low-slag High-feo Sinteredmentioning

confidence: 99%

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Reducing Slag Volume at Cohesive Zone of Blast Furnace by using Low-slag Sintered Ore with Reducible Magnetite

et al. 2022

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“…Since adding dolomite to the blast furnace will bring a series of adverse effects [7][8][9], magnesium-containing fluxes are usually added during the sintering process. As for the effects of magnesium flux on the sintering process, previous studies have shown that MgO has a negative effect on the strength and reducibility index and a positive effect on the reduction degradation index of the sinter [10][11][12][13][14][15]. It can be seen that the reaction behavior of MgO is closely related to the quality index of sintering production.…”

Section: Introductionmentioning

confidence: 95%

The Macroscopic Flow direction and Microscopic Distribution of Mg in Sintered Products and Its Influence

Zhang

Kou

et al. 2018

Metals

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Magnesium flux is an indispensable part of sintering materials. Its distribution and reaction behavior have an important influence on the quality of the sinter. Studying the macroscopic flow direction and microscopic distribution of MgO in sintered products is important for guiding the matching of ore for sintering and adjusting sintering technical parameters. The macroscopic flow direction situation of MgO in all sintered products was studied using X-Ray diffractometer and X-Ray fluorescence analyzer. In addition, the microscopic distribution characteristics of Mg element in the main sintered products were studied using scanning electron microscope and energy dispersive spectrometer. The results of this research are as follows. The Mg contents of sintered products are in the following increasing order: sinter ore, sinter internal return ore, and blast furnace return ore. The Mg content of the 1 to 2 mm grain size is the highest in the sinter internal return ore and blast furnace return ore, which is related to the granular distribution of magnesium flux. Moreover, the Mg content of sintered minerals are in the following decreasing order: magnetite; silico-ferrites of calcium and aluminium (SFCA); and silicate and hematite, and the Mg dissolving in the SFCA has a tendency to make the SFCA morphology coarse. The diffusion range of Mg in a large dolomite particle is much narrower, and it mainly stays at the position where the dolomite is located. In the actual sintering process, Mg increases the viscosity of the sintering liquid phase and prevents the oxidation of magnetite, which is not conducive to the improvement of the strength of the sinter.

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Competitive Formation Behavior of Calcium Silicate and Calcium Ferrite in Sintering of Iron Ore Fines

Du,

Wei,

Guo

2024

steel research int.

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Calcium silicate is the undesirable bonding phase in sinter with relatively high melting point and poor reducibility, while the formation mechanism in sinter is ambiguous. Herein, the phase transformation, phase quantification, and morphology evolution of calcium silicate and calcium ferrite in CaO‐SiO2‐Fe2O3‐Al2O3 systems under different n(Fe2O3)/n(CaO) and Al2O3 content are investigated. It is found that with the increase of n(Fe2O3)/n(CaO), the calcium ferrite phases transform from Ca2Fe2O5 (C2F) to complex calcium ferrite, and calcium silicate phases including β‐Ca2SiO4 (β‐C2S) and γ‐Ca2SiO4 (γ‐C2S) are promoted. Moreover, small amount (2%) of Al2O3 can effectively promote the content of silico‐ferrite of calcium and aluminum (SFCA) increasing from 20.95% to 46.69%, whereas inhibiting the β‐C2S from 51.79% to 42.34%. When the content of Al2O3 is over 4%, the Ca2Al(AlSiO7) phase is formed, where both the SFCA and calcium silicate are inhibited. On this base, the competitive mechanism for the formation of calcium silicate and calcium ferrite is revealed, where the Ca2+ and Si4+ are preferred to react with Fe3+ and Al3+ to form liquid phase SFCA, while the amount for β‐C2S or γ‐C2S can be decreased due to the deprivation of Ca2+ and Si4+.

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Role of MgO in Sinter from Perspective of MgO Distribution between Liquid and Magnetite Phases in FeO<sub>x</sub>–CaO–SiO<sub>2</sub>–MgO System

Cited by 7 publications

References 19 publications

Reducing Slag Volume at Cohesive Zone of Blast Furnace by using Low-slag Sintered Ore with Reducible Magnetite

Reducing Slag Volume at Cohesive Zone of Blast Furnace by using Low-slag Sintered Ore with Reducible Magnetite

The Macroscopic Flow direction and Microscopic Distribution of Mg in Sintered Products and Its Influence

Competitive Formation Behavior of Calcium Silicate and Calcium Ferrite in Sintering of Iron Ore Fines

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