Use of magnesian-dolomite mixtures in steel-melting furnace hearths and the mechanism of their wear in service. 1. Study of Jehearth refractory mixture

Shchekina, T. I.; Gramenitskii, E. N.; Batanova, A. M.; Kurbyko, T. A.; Likhodievskii, A. V.; Grigor’ev, B. N.; Pyrikov, A. N.; Sheshevichka, O.; Gazhur, R.

doi:10.1007/s11148-007-0009-5

Cited by 3 publications

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“…Periclase is stable over the whole column with ferrous coefficients of 0.03 and it increases to 0.2 in zone 4. The presence in all zones, including the original mix, of titanium-containing phases distinguishes this column of refractory reaction with melt from previously studied columns [1,2], where Ti was an impurity element. In the zero zone of the composition the titanium phase is close to the stoichiometry of perovskite; with an increase in the intensity of the process the titanium phase becomes more aluminous.…”

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Wear mechanism for periclase material in open-hearth furnace bottoms

et al. 2008

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Results are provided for a mineral petrographic study of reaction with molten metals of refractory material grade PPM-85 produced by OAO Kombinat Magnezit. Features are revealed for the change in its phase and chemical composition and the wear mechanism is considered during operation in an open-hearth furnace. 6Results of mineral petrographic studies of magnesia materials used in the hearths of open-hearth furnaces make it possible to reveal features of the change in phase and chemical compositions of refractory mixes subjected to chemical corrosion during reaction with metallurgical melts in service. In this work the wear mechanism has been studied for the bottoms of open-hearth furnaces during service using magnesia powders grade PPM-85 produced by OAO Kombinat Magnezit for ramming them. Ankerhearth [1] and Jehearth [2] magnesia-dolomite mixes produced overseas have been studied previously.Material PPM-85 has been studied before and after operation in an open-hearth furnace bottom in OAO Chusovoi Metallurgical Plant. Optical and electron microscopy, local x-ray spectral (microprobe), silicate and x-ray phases analyses were used for this purpose. In order to study the reaction column forming in a refractory material of the hearth a procedure was used developed for metasomatic natural processes [3] and processes of magmatic displacement of rock by magmatic melts [4].The original mix PPM-85 (GOST 24682) based on fired magnesite is a light-gray powder with a predominant grain size of tenths of a millimeter (specimen M32); 20 -30% of the volume consists of a different size (up to 8 mm), together with aggregates of periclase grains, sintered into a dense firm mix and cemented with calcium silicates. According to x-ray phase analysis data samples of different fractions of the original mix consist of 84% periclase and 16% x-ray amorphous substance. The individual reflections are identified as belonging to tri-and bicalcium silicates. Silicate analysis was used to determine the empirical chemical composition of an average sample selected from material of different fractions (Table 1). This analysis rested upon comparison with data for the material composition after service. Local x-ray spectral analysis was used to study the phase and empirical chemical composition of coarse fragments with a size of 3 -5 mm (Tables 1 and 2).According to electron microscopy data periclase of the original material is aggregates of polygonal grains (Fig. 1a ) with a size of 0.5 -2.0 mm (predominantly a size of 0.1 mm) and it has a stable iron coefficient of 0.03. The binding mass in the form streaky strips with a width up to 0.1 mm consists of crystals of bicalcium silicate and skeletal strips, i.e. calcium titanate (perovskite), forming typical growths. Within the composition of bicalcium silicate 10 -12% Ca replaces Mg; in addition, within it there are permanently present admixtures of Ti, Al and Fe. Within the composition of perovskite phase 10% titanium is replaced by Al; in addition it contains admixtures of Si, Mg and Fe.It follows f...

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“…In this work the wear mechanism has been studied for the bottoms of open-hearth furnaces during service using magnesia powders grade PPM-85 produced by OAO Kombinat Magnezit for ramming them. Ankerhearth [1] and Jehearth [2] magnesia-dolomite mixes produced overseas have been studied previously.…”

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Wear mechanism for periclase material in open-hearth furnace bottoms

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“…MgO particles burned at lower temperature are bigger than those at high temperature, and resulting in expansion at early age. Shchekina et al [50] Use of magnesian-dolomite mixtures in steel-melting furnace hearths and the mechanism of their wear in service.…”

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Review on the elaboration and characterization of ceramics refractories based on magnesite and dolomite

Sadik

Moudden

Bouari

et al. 2016

Journal of Asian Ceramic Societies

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One of the most important elements of furnaces, boilers and other heating units is the structure (lining), usually made of silica-alumina, basic or special refractories. The basic refractories are materials that are increasingly in demand and whose manufacturing involves necessarily the use of MgO and CaO. In this article, the description and characterization of magnesite (MgCO 3) and dolomite (Mg,Ca(CO 3) 2) and their contribution in industrial ceramics-refractories have been reviewed.

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“…During performance of this work the hearth wear mechanism was studied during service using for ramming magnesia powder grade PPM-85 (GOST 24862) of domestic production (OAO Kombinat Magnezit). Previously magnesia dolomite mixes grade Ankerhearth [1] and Jehearth grade [2], obtained from overseas enterprises, were studied for this purpose.…”

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Technogenic mineral formation in refractory materials in the open-hearth process

et al. 2011

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Zonal changes have been studied for a refractory mix of OAO Kombinat Magnezit (Satka) on reaction with melt in the open-hearth process. Four zones of change are isolated. In successive zones there is a reduction in MgO content in the material and a relative increase in the amount of CaO, TiO 2 , Al 2 O 3 , SiO 2 , and Fe. In this direction there is an increase in feruginosity of periclase and an increase mix porosity, melt and substitution solid phases appear. These changes reduce refractory mix resistance and promote its breakdown.A study has been made in a series of researches by authors of the present article of features of the change in phase and chemical composition of magnesia refractory mixes, used in the hearths of open-hearth furnaces and subject to chemical corrosion during their reaction with metallurgical melts. During performance of this work the hearth wear mechanism was studied during service using for ramming magnesia powder grade PPM-85 (GOST 24862) of domestic production (OAO Kombinat Magnezit). Previously magnesia dolomite mixes grade Ankerhearth [1] and Jehearth grade [2], obtained from overseas enterprises, were studied for this purpose.In studying material the methods used were microprobe, silicate and x-ray phase analysis, optical and electron microscopy. In particular microprobe analysis complex of the petrology faculty of MGU was used on the basis of a Jeol JSM 6480DMÉ microscope with a combined system for x-ray spectral scanning microanalysis combining energy dispersion INCA-Energy 350 and wave diffraction four-crystal INCA-wave 500 spectrometers. Photographs provided in the article were taken in reverse scattered electrons. The original refractory powder grade PPM-85 (fired magnesite of the Satka deposit) represents the material with a predominant grain size comprising tenths of a millimeter. Within 20 -30 vol.% of the powder fragments of various sizes are present (from several millimeters to 3 mm) sintered into a dense mass. Periclase in the from of aggregates of polygonal grains with a size of 0.5 -2.0 mm have a stable feruginosity factor of 0.3. The binder mix consists of skeletal crystals of bicalcium silicate and calcium titanate (perovskite) cementing them. Within the composition of bicalcium silicate 10 -12% Ca is replaced by Mg; in addition, within it there is a permanent presence of impurities, Ti, Al, and Fe. Within the composition of the perovskite phase 10% of the titanium is replaced by Al; in addition it contains impurities of Si, Mg, and Fe. From the position in the material microstructure and according to phase composition diagrams these two phases separated from the melt.In specimens of refractory material that are within the region of metallurgical melt reaction on the refractory mix, there is clear zonality, expressed as a change in color, texture and chemical composition (Table 1). Removal from contact with the melt zone 1 is characterized by a dense deposit of small to medium grain size. Zone 2, with a thickness of 5 -14 mm of gray color has a brecciated structure d...

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Use of magnesian-dolomite mixtures in steel-melting furnace hearths and the mechanism of their wear in service. 1. Study of Jehearth refractory mixture

Cited by 3 publications

References 3 publications

Wear mechanism for periclase material in open-hearth furnace bottoms

Wear mechanism for periclase material in open-hearth furnace bottoms

Review on the elaboration and characterization of ceramics refractories based on magnesite and dolomite

Technogenic mineral formation in refractory materials in the open-hearth process

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