Controlled Solidification of Liquids Within the SFC Primary Phase Field of the “Fe2O3”-CaO-SiO2 System in Air

Nicol, Stuart; Jak, Evgueni; Hayes, Peter C.

doi:10.1007/s11663-019-01689-8

Cited by 13 publications

(33 citation statements)

References 12 publications

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“…Due to the small size of the unknown calcium ferrite crystals, the phase could not be positively identified by EPMA but are assumed to be calcium ferrite crystals. Based on the composition difference between the hematite and magnetite, calcium is rejected to a second phase, with potential candidates including SFC, SFC-I, CF 2 , CF and Ca 7.2 Fe 2+ 0.8 Fe 3+ 30 O 57 [15].…”

Section: Mechanisms Of Formation Of Hematite and Magnetitementioning

confidence: 99%

Measurement of Process Conditions Present in Pilot Scale Iron Ore Sintering

Nicol

Chen

et al. 2019

Minerals

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An improved experimental technique has been developed to measure, concurrently, the oxygen partial pressures and temperatures within a pilot scale iron ore sinter pot as a function of time. The measurements and thermodynamic calculations have demonstrated that the oxygen partial pressure at peak bed temperature and during cooling can be oxidising or reducing relative to hematite. Examples of typical microstructures and phase assemblages observed in product sinters are presented. Potential mechanisms of hematite and magnetite formation at sub-liquidus and sub-solidus conditions are demonstrated. The relative impacts of changes to coke rate and draft pressure drop on the process conditions and proportions of the phases formed in the sinter have been measured. Increasing coke rate was shown to result in a faster sinter heating rates, higher peak bed temperatures and times at peak temperature. Higher draft pressures across the sinter bed resulted in faster sinter heating rates and shorter times at peak temperature.

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Section: Mechanisms Of Formation Of Hematite and Magnetitementioning

confidence: 99%

Measurement of Process Conditions Present in Pilot Scale Iron Ore Sintering

Nicol

Chen

et al. 2019

Minerals

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“…It has been postulated that the different iron oxide morphologies and phase associations result in different sinter properties. 1) A series of studies have been undertaken to determine the stages and phase assemblages occurring during the solidification of "Fe 2 O 3 "-CaO-SiO 2 melts 2,3) and the effects of cooling rate on the phases formed and the resulting microstructures on solidification of these melts. 4) In the present study, a systematic investigation of the effects of changing bulk Fe 2 O 3 concentration, independent of other controllable parameters, on the microstructures and phases formed on cooling "Fe 2 O 3 "-CaO-SiO 2 melts at conditions relevant to iron ore sintering is described.…”

Section: Introductionmentioning

confidence: 99%

Effects of the Bulk Fe2O3 Concentration on the Controlled Solidification of “Fe2O3”–CaO–SiO2 Liquids in Air

2020

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The solidification of "Fe 2 O 3 "-CaO-SiO 2 liquids in air at a controlled cooling rate of 2.0 K/s for a range of Fe 2 O 3 concentrations in the bulk has been investigated. The compositions investigated were selected such that the bulk compositions were within the hematite primary phase field and had a CaO/SiO 2 ratio of 3.46 wt/wt.Non-equilibrium phase assemblages were formed for all bulk compositions investigated. Specifically, the silico ferrite of calcium (SFC) phase was not formed on cooling. The microstructures and proportions of the phase assemblages formed were found to vary with the Fe 2 O 3 concentration in the bulk.

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“…The literature studies also suggest that the form consisting of hematite cores surrounded by SFCA-I is the desired structure for high sinter quality [7,18,19]. During the reduction reactions, the porous structure of the acicular SFCA has been proven to provide a wide surface contact to prevent spread of cracks [10,30]. In the examination of the sinter phase structure (shown in Figure 6); it has been observed that start of mineral compositions, CF3 (CaO.3Fe2O3), CA3 (CaO.3AI2O3) and C4S3 (4CaO.3SiO2) or Fe2O3-AI2O3-CaO compounds can be designed to be able to create a link in a planar structure [13,18,19,30].…”

Section: Resultsmentioning

confidence: 99%

“…During the reduction reactions, the porous structure of the acicular SFCA has been proven to provide a wide surface contact to prevent spread of cracks [10,30]. In the examination of the sinter phase structure (shown in Figure 6); it has been observed that start of mineral compositions, CF3 (CaO.3Fe2O3), CA3 (CaO.3AI2O3) and C4S3 (4CaO.3SiO2) or Fe2O3-AI2O3-CaO compounds can be designed to be able to create a link in a planar structure [13,18,19,30]. In the study, the SFCA composition encountered in the industrial sinter was observed and triple phase diagrams were drawn as SFCA forms, SFCA, SFCA-I and SFCA-II (dendritic) solid solution series [13,19].…”

Section: Resultsmentioning

confidence: 99%

A Study on Analysis of Sinter Microstructure and Phase Morphology

Bölükbaşı

2021

Sakarya University Journal of Science

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Sinter is a blast furnace input material obtained by temperature to 900-1200 o C without full melting and adhering to each other with superficial melting. It is considered as a multi-phase material with its heterogeneous microstructure. In general, the main mineral phases are hematite, magnetite, silicoferrite of calcium and aluminium (SFCA) and silicates. By determining the SFCA structure in the sinter material, the sintering process will be made more stable and important parameters affecting the quality in the sintering process will be examined. Sinter material consists of iron ore, iron and steel industry by-products and auxiliary materials. The scope of this project is the determination of the amount of SFCA formed by bonding SiO2, CaO, Fe2O3, Al2O3 and MgO compounds and monitoring this value as a parameter by sinter manufacturers. Sinter samples having different characteristic features were made ready for Xray diffraction (XRD) and optical microscopy inspections by polishing, etching and cold mounting in epoxy for mineralogical analyses. Before raw data obtained from the analysis were evaluated at Autoquan, they were converted into Autoquan format and then, read in XRD device and mineralogical composition of the sinter was revealed by XRD analyses. Detailed imaging of mineralogical compounds were made so as to complement scanning electron microscope (SEM) analyses and XRD analyses; elemental composition of the compounds and valence conditions of the elements were determined by energy dispersive spectroscopy (EDS) method. Phase structures such as hematite, magnetite, and calcium ferrite were qualitatively determined by mineralogical investigations on sinter samples. Furthermore, the variations of SFCA phases (SFCA, SFCA-I and SFCA-II) were studied through Rietveld method.

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Controlled Solidification of Liquids Within the SFC Primary Phase Field of the “Fe2O3”-CaO-SiO2 System in Air

Cited by 13 publications

References 12 publications

Measurement of Process Conditions Present in Pilot Scale Iron Ore Sintering

Measurement of Process Conditions Present in Pilot Scale Iron Ore Sintering

Effects of the Bulk Fe<sub>2</sub>O<sub>3</sub> Concentration on the Controlled Solidification of “Fe<sub>2</sub>O<sub>3</sub>”–CaO–SiO<sub>2</sub> Liquids in Air

A Study on Analysis of Sinter Microstructure and Phase Morphology

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