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  • Author or Editor: J. Orewczyk x
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Abstract  

The paper presents results of research on the effect of the presence of calcium and magnesium in magnetite structure on its reducibility. These are model studies of the phase which mostly affects reducibility of superfluxed sinter. Examinations were carried out on samples melted and crystallized in a single crystal growing process.

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Abstract  

This paper presents applications of thermal analysis to observe the course of reduction of acidic pellets, metallurgical substances whose reducibility and strength are basic parameters of use in blast furnace processes. Both parameters depend on the mineral composition of the samples. The investigations included determination of the chemical and phase compositions of the initial samples and reduction products. Research was conducted on acidic pellets from Połtawa (Poland), applied in the T. Sendzimir Steelworks (Poland), in comparison with pellets from Brazil, Canada and Lebedyn (Russia).

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Abstract  

This paper present results of research performed on briquettes containing iron oxides with the aiming of establishing a relationship between their chemical and phase compositions. Briquettes obtained from industrial in-plant fines waste were subjected to experimental tests involving simulation of the temperature conditions and the redox potential of a gas phase, characteristic of both the top and central parts of a blast furnace. The results of the analysis allowed conclusions concerning the use of briquettes as a blast furnace charge component.

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Abstract  

Investigation of pure and calcium doped phase is the model investigation of phase which determine the blast turnace sinter reducibility. The object of examination are mono- and polycrystalline calciomagnetites of large grains dimension Fe3−xCaxO where 0.04≤x≤0.25. The solubility limit of calcium in magnetite was strictly defined and changes of some physico-chemical properties as well.

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Abstract  

Application of thermal analysis to determine a quantity portion of iron oxides in symmetric blast furnace sinters is presented. In the multicomponent sample, calcium ferrites and many silicate phases beside doped iron oxides phases were observed. The dependence of sinter phase composition from basicity and relation with physicochemical properties is defined.

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Abstract  

The aim of this work was to investigate the application of mixtures of high-basicity sinters and acidic pellets in blast furnace charges. The ratio of high-basicity sinter and pellets depends on the nature and basicity of the latter, and is established in order to secure desired properties of the slag and sufficient reducibility and mechanical strength of the furnace charge. Such a composition of the charge leads to a considerable cost decrease related to coke saving, the elimination of fluxes and a decrease in air pollution. Examinations of phase composition and physicochemical properties of the sinters and pellets as separate materials were carried out. The effect of the mineral composition of sinters with a basicity of 1.7–2.0 on the reducibility was determined. Sinters of different basicities (CaO/SiO2=1.7; 2.0) mixed with pellets from Poltawawere reduced in a CO/CO2 gas mixture. The reduction process was followed by thermal analysis.

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