Computational Insights into Interactions between Ca Species and α-Fe2O3(0 0 1)

Yan-qin, Sun; Lü, Qing; Wan, Xinyu; Zhang, Shuhui; Zhang, Jiongming

doi:10.1016/s1006-706x(14)60064-9

Cited by 4 publications

(3 citation statements)

References 17 publications

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“…There was little hematite present, which was the main reason the sinter had a reduced degradation during the phase transformation of Fe 2 O 3 → Fe 3 O 4 . This was associated with a volume increase of 10%, which led to degeneration during the reduction process at 450-500 • C [12,21,22]. Another cause for the high RDI +3.15 value could be the uniform microstructure, sufficient liquid, few pores, and lack of perovskite.…”

Section: Metallurgical Performancementioning

confidence: 99%

Study on Sintering Characteristics of Ultra-Poor Vanadium-Titanium Magnetite

et al. 2021

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Artificial rich ore for blast furnace use can be produced by sintering ultra-poor vanadium-titanium magnetite (PVTM) with a high-grade iron concentrate. Here, acid (R = 0.33, 0.50), self-fluxing (R = 1.10), and high-basicity (R = 2.60) PVTM sinters were produced in a sinter pot. Their performances were determined using the comprehensive index. The microstructures of the PVTM sinter were observed by metallographic microscope and scanning electron microscopy equipped with an energy dispersion spectrum (SEM-EDS). The results suggest that the acid PVTM sinter had a low flame front speed, low productivity, an uneven size distribution, and poor softening properties. It did have a high tumble index (TI) and low-temperature reduction disintegration index (RDI). The self-fluxing PVTM sinter had the worst performance (TI, RDI, reducibility index (RI)), while the high-basicity PVTM sinter had the highest flame front speed, highest productivity, a reasonable size distribution, excellent softening properties, and satisfactory TI and RDI values. The main consolidation form of the acid sinter was crystal stock, the main bonding phase of the self-fluxing sinter was silicate, and the main bonding phase of the high-basicity sinter was silico-ferrite of calcium and aluminum (SFCA). The comprehensive index values (from high to low) were the high-basicity (R = 2.60), acid (R = 0.50), natural acid (R = 0.33), and self-fluxing (R = 1.10) PVTM sinters. When the production capacity of the acid pellet was in shortage, the acid PVTM sinter (R = 0.50) could be produced by the surplus from the sinter plant. This replaced a part of the acid pellet and the burden structural model of the blast furnace smelting vanadium so the titanium burden could adopt a ‘high-basicity PVTM sinter + acid V-Ti pellet + acid (R = 0.50) PVTM sinter’.

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Section: Metallurgical Performancementioning

confidence: 99%

Study on Sintering Characteristics of Ultra-Poor Vanadium-Titanium Magnetite

et al. 2021

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“…The viscosity and the TiO 2 content of the slag are high in the blast furnace (BF) iron-making process, due to the high TiO 2 content in the CCVTM. The slag experiences a decreased ability for desulfurization, and it is difficult to separate the slag from the iron [8][9][10][11][12][13].…”

Section: Introductionmentioning

confidence: 99%

Effects of Dolomite on Mineral Compositions and Metallurgical Properties of Chromium-Bearing Vanadium–Titanium Magnetite Sinter

et al. 2017

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Abstract:Chengde chromium-bearing vanadium-titanium magnetite (CCVTM) has been used as an important mineral resource in sinter making. The MgO content of this sinter can be enhanced by adding dolomite, which improved operation of the blast furnace. The effects of MgO in the form of dolomite on metallurgical properties, microstructure and mineral compositions of CCVTM sinter were studied by a sinter pot test, X-Ray Diffraction (XRD), Scanning Electron Microscope (SEM), and mineral phase microanalysis. The results were as follows: The flame front speed and sinter coefficient decreased with an increase in MgO content from 2.66 to 3.86% by adding dolomite. With an increase in MgO content from 2.66 to 3.86%, the flame front speed, sintering utilization factor, and the value of RI decreased, while RDI and the softening-melting properties improved. In addition, the value of sinter strength (TI) reached a maximum value at MgO = 3.56%. In addition, an increase in the abundance of magnetite, magnesium ferrite, and silicate phase, as well as a decrease in hematite, was found with an increase in MgO content. We concluded that the most appropriate MgO content in the sinter is 3.56%.

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“…Pseudopotential chooses the ultra-soft pseudopotentials in reciprocal space representation. The plane-wave has the cutoff energy of 350 eV in all calculations, and the value of k-points is 4 × 4 × 1 [15,16,19,20]. The values of convergence criterial for energy is 2.0 × 10 −5 eV/atom, maximum force is 0.005 Ha/Å, maximum stress is 0.1 GPa, displacement in Self Consistent Field (SCF) is 0.002 Å.…”

Section: Computational Detailsmentioning

confidence: 99%

Combined Density Functional Theory and Reduction Kinetics Investigation of Enhanced Adsorption of Hydrogen onto Fe2O3 by Surface Modification with Nickel

Zhang

Wei

et al. 2019

Metals

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Based on the density functional theory, the geometric structure, adsorption energy and density of states of H 2 /α-Fe 2 O 3 (001) system and (H 2 + Ni)/α-Fe 2 O 3 (001) system were determined. The results showed that the absolute value of adsorption energy between H 2 molecule and α-Fe 2 O 3 (001) surface and the bond length of H 2 molecule were increased by the presence of Ni atom. The presence of Ni atom promotes the adsorption of H 2 molecule on α-Fe 2 O 3 (001) surface. Reduction behavior of iron and nickel oxides in H 2 atmosphere was determined by thermogravimetric analysis. The samples included Fe 2 O 3 , Fe 2 O 3 -NiO and Fe 2 O 3 -Ni systems. The effect of Ni and NiO on the reduction behavior of Fe 2 O 3 was investigated. The ease of reduction within the following three systems decreases sequentially: Fe 2 O 3 -Ni > Fe 2 O 3 -NiO > Fe 2 O 3 . The activation energy of Fe 2 O 3 -Ni, Fe 2 O 3 -NiO and Fe 2 O 3 systems at two temperature stages (viz. < 400 • C and > 400 • C) were 172 kJ·mol −1 , 197 kJ·mol −1 and 263 kJ·mol −1 respectively.

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Computational Insights into Interactions between Ca Species and α-Fe2O3(0 0 1)

Cited by 4 publications

References 17 publications

Study on Sintering Characteristics of Ultra-Poor Vanadium-Titanium Magnetite

Study on Sintering Characteristics of Ultra-Poor Vanadium-Titanium Magnetite

Effects of Dolomite on Mineral Compositions and Metallurgical Properties of Chromium-Bearing Vanadium–Titanium Magnetite Sinter

Combined Density Functional Theory and Reduction Kinetics Investigation of Enhanced Adsorption of Hydrogen onto Fe2O3 by Surface Modification with Nickel

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