In situ X-ray diffraction analysis of iron ore sinter phases (original) (raw)
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Powder Diffraction, 2014
The formation and decomposition of silico-ferrite of calcium and aluminium (SFCA) and SFCA-I iron ore sinter bonding phases have been investigated using in situ synchrotron and laboratory X-ray diffraction (XRD) and neutron diffraction (ND). An external standard approach for determining absolute phase concentrations via Rietveld refinement-based quantitative phase analysis is discussed. The complementarity of in situ XRD and ND in characterising sinter phase formation and decomposition is also shown, with the volume diffraction afforded by the neutron technique reducing errors in the quantification of magnetite above ∼1200°C. Finally, by collecting 6 s laboratory XRD datasets and using a heating rate of 175°C min −1 , phase formation and decomposition have been monitored under heating rates more closely approximating those encountered in industrial iron ore sintering.
A Short Review of the Effect of Iron Ore Selection on Mineral Phases of Iron Ore Sinter
Minerals, 2021
The sintering process is a thermal agglomeration process, and it is accompanied by chemical reactions. In this process, a mixture of iron ore fines, flux, and coal particles is heated to about 1300 °C–1480 °C in a sinter bed. The strength and reducibility properties of iron ore sinter are obtained by liquid phase sintering. The silico-ferrite of calcium and aluminum (SFCA) is the main bonding phase found in modern iron ore sinters. Since the physicochemical and crystallographic properties of the SFCA are affected by the chemical composition and mineral phases of iron ores, a crystallographic understanding of iron ores and sintered ore is important to enhance the quality of iron ore sinter. Scrap and by-products from steel mills are expected to be used in the iron ore sintering process as recyclable resources, and in such a case, the crystallographic properties of iron ore sinter will be affected using these materials. The objective of this paper is to present a short review on resea...
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Iron ore sinters are considered as multi-phase materials, with a heterogeneous microstructure. The amounts of the different phases mainly hematite, magnetite and a dicalcium silicate are contributing factors to a number of important on the sinter quality. The behavior of phase formation during the sintering process has a significant of effect on the chemical composition of sinter and controlling microstructure and concentration of silicoferrites of calcium and aluminum (SFCA). The mineralogical distribution of different phases determines the microstructure of the sinter which imparts the quality of the sinter. In this study, the microstructure of the sinter has been examined by considering the chemical composition, the mineralogy, the morphology and the spatial arrangement of the various mineral phases formed during sintering. The chemical composition in the process of sintering (especially CaO, Al2O3, Fe2O3, SiO2 etc.) were made optimum control and all parameters that can effect on...
Metallurgical and Materials Transactions B, 2014
The effect of MgO on the stability, concentrations and formation mechanisms of silico-ferrite of calcium and aluminum (SFCA and SFCA-I) iron ore sinter bonding phases during heating in synthetic mixtures was investigated using in situ x-ray diffraction. The novelty of this study is in the intricate detail in which the formation mechanisms of the SFCA-I and SFCA phases are characterized, and the observation of the effects of MgO addition on intermediate phases. For example, the significant mechanistic effect of increasing MgO content is the lack of additional SFCA formed after SFCA-I decomposition, with additional magnesioferrite spinel being formed instead. In MgO-free mixtures, the decomposition of SFCA-I typically results in a significant increase in SFCA concentration. Through the results of phase equilibria experiments, this study also provides evidence that the SFCA-I structure accommodates more Mg 2+ than the SFCA structure, which is consistent with evidence that the SFCA-I structure contains a higher amount of Fe 2+ than SFCA.
JOM, 2020
The effect of MgO on the stability, concentrations and formation mechanisms of silico-ferrite of calcium and aluminum (SFCA and SFCA-I) iron ore sinter bonding phases during heating in synthetic mixtures was investigated using in situ x-ray diffraction. The novelty of this study is in the intricate detail in which the formation mechanisms of the SFCA-I and SFCA phases are characterized, and the observation of the effects of MgO addition on intermediate phases. For example, the significant mechanistic effect of increasing MgO content is the lack of additional SFCA formed after SFCA-I decomposition, with additional magnesioferrite spinel being formed instead. In MgO-free mixtures, the decomposition of SFCA-I typically results in a significant increase in SFCA concentration. Through the results of phase equilibria experiments, this study also provides evidence that the SFCA-I structure accommodates more Mg 2+ than the SFCA structure, which is consistent with evidence that the SFCA-I structure contains a higher amount of Fe 2+ than SFCA.
X – Ray Diffraction Analysis of Iron Sinter
Acta Metallurgica Slovaca - Conference, 2014
Producers of iron sinter need precise phase analysis for effective operation supervision. It is not enough to consider only chemical composition, but it is beneficial to know the iron sinter mineralogical composition. Producers can utilize this information for better sinter mechanical properties adjustment and sinter yield improvement. When iron ore fines under 6mm are mixed with limestone flux, recycled materials and coke breeze, and are heated to about 1250°C the iron sinter is obtained. Produced iron sinter is in partial melting of mixture porous, but physically strong enough heterogeneous material, in which the iron bearing minerals are bonded together by range of different phases, where complex ferrite phases are very well known as SFCA (Silico-Ferrite of Calcium and Aluminum). Sinter is used as feed material for blast furnace. Using X-ray diffraction method and Rietveld method in the TOPAS program, the existing phases were identified both qualitatively and quantitatively.