Refractories based on fused pe riclase ? Chromite material for vacuum steel refining plants

Chernyavskaya, V. P.; Bocharov, L. D.; Voinikova, L. A.; Oriov, V. A.; Marants, A. G.; Соколов, А. Н.; Kononchuk, O. P.; Kuznetsov, G. I.

doi:10.1007/bf01282336

Cited by 6 publications

(7 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Some authors [2] consider that the main cause is the accelerated firing cycle for the briquette as it is converted into chamotte in an oxidizing atmosphere; others [6] consider firing in a reducing atmosphere. Some authors [7] assume an expansion of the products to be connected with mullitization which takes place during firing, or to be a consequence of the bloating of the material, which is due to the incomplete phase conversion [3,4] and the expansion of the gas in the closed pores [6,8].…”

Section: Propertiesmentioning

confidence: 99%

“…The Magnezit combine prepared specimens and articles as follows: periclase-chromite (PKhVP) based on granular fused periclase-chromite and finely milled periclasc-chromitic mixture [7]; periclase-spinel PShPV and PShSV based on sintered magnesite and granular fused [8] and sintered [8,9] spinel MgA1204; periclase-chromitic PKhV and PShS based on sintered magnesite and chromite, respectively, granular and finely milled simultaneously [10] and only finely milled [11]; magnesite-chromite MKhS based on sintered magnesite Magnezit Combine. East…”

mentioning

confidence: 99%

See 1 more Smart Citation

Thermomechanical and deformation properties of periclase and magnesia-spinel refractories

1983

Self Cite

View full text Add to dashboard Cite

this case the thermal conductivity of the goods is hardly impaired. We developed optimum compositions for these refractories, enabling us to reduce the linear shrinkage to 1% in the 1100-1300~ range. It is shown that a reduction in the linear shrinkage of the tiles with the addition of alumina and magnesia occurs on account of the overall increase in the volume during the synthesis of magnesia spinel, mullite in the bond, and a-cristobalite. The linear shrinkage of fibrous specimens with fused quartz is reduced on account of the increase in the volume during the cristobalitization of the fused quartz. The Bogdanovich factory made a trial batch of fibrous articles with a low shrinkage during heating which were established in the working layer of a soaking pit at the Hammer and Sickle Steel Plant.LITERATURE CITED 1. G.C. Padgett and P. T. A. Hocson, Metallurgia, 477, No. 6, 308-313 (1980). 2."Ceramic fiber blanket covers furnace hot-face lining needs," Southam's Metalwork, 35,No. 8, 6-9 (1972 The scientific principles of the mechanics of failure of ceramics, and review data on their strength, have been published in [1][2][3][4][5][6].The effectiveness of using refreactories in high-temperature technology is determined by their thermomechanical and deformation properties. The investigation of these properties is essential in order to create and improve methods for periclase and magnesia-spinel refractories for progressive methods of producing a steel and for other areas of technology.This article describes the results of studies of these properties in conventional and new types of periclase and magnesia-spinel refractories and the relationship between these properties and the structure and other factors.The Magnezit combine prepared specimens and articles as follows: periclase-chromite (PKhVP) based on granular fused periclase-chromite and finely milled periclasc-chromitic mixture [7]; periclase-spinel PShPV and PShSV based on sintered magnesite and granular fused [8] and sintered [8,9] spinel MgA1204; periclase-chromitic PKhV and PShS based on sintered magnesite and chromite, respectively, granular and finely milled simultaneously [10] and only finely milled [11]; magnesite-chromite MKhS based on sintered magnesite Magnezit Combine. East

show abstract

Section: Propertiesmentioning

confidence: 99%

mentioning

confidence: 99%

Thermomechanical and deformation properties of periclase and magnesia-spinel refractories

1983

Self Cite

View full text Add to dashboard Cite

show abstract

“…

At present one of the best high-duty magnesia-spinel refractories is PShPKh, based on fused periclase-chromite, chrome-alumina spinel, periclase, obtained by fusing in the block in arc furnaces.

…”

mentioning

confidence: 99%

Refractories based on sintered and fused periclase-chromite

et al. 1991

View full text Add to dashboard Cite

The technology for magnesia-spinel refractories developed in the USSR specifies the production of goods from sintered periclase powder and chromite ore added to the batch in granular form (PKhS) [i]; in the form of finely dispersed mixtures with sintered periclase powder (PShS) [2]; combinations of both versions (PKhV), and also on the basis of granular fused periclase-chromite mixture (PKhVP) [4]; granular fused periclase chromite, chrome-alumina spinel, and finely dispersed fused periclase (PShPKh) [5]; fused (PShPV) and sintered (PShSV) [6,7] granular aluminomagnesia spinel and sintered periclase powder, sintered periclasechromite clinker (KPShS) [8]. Goods from clinker obtained with nonpelletized [9] and pelletized [i0] fine mixtures of caustic magnesite and chromite calcined in rotary kilns 90 m long at 1760-1790~ (at the flame) and cooled in the range tmax-900"C at a rate of 95-100~ are slightly different with respect to the standard (porosity, strength, thermal-shock resistance, refractoriness under load of 0.3 N/mm2), but are suitable distinguished from PShS goods, both in terms of thermal strength, thermal fatigue, porous structure and of wear resistance in the linings of open-hearth roofs [9, i0].At present one of the best high-duty magnesia-spinel refractories is PShPKh, based on fused periclase-chromite, chrome-alumina spinel, periclase, obtained by fusing in the block in arc furnaces. The preparation of fused periclase-chromite is connected with a high specific consumption of batch, electrodes, energy and labor; separating the blocks is laborious and limits the increase in production of PShPKh goods, and greatly affects their cost.In order to study the possibility of replacing fused periclase-chromite in the batch for PShPKh goods by sintered material, we carried out industrial experiments in the TsMI-2 section of the Magnezit Combine.The sintered periclase-chromite was prepared from caustic magnesite and chrome concentrate (Table i) by combined milling in the ratio 80:20 to a residue on a screen with i0,000 apertures per cm 2 of less than 10%, moistening during blending with a water solution of LST having a density of 1.24 g/cm 3 to a moisture content of 2.8-3.6%, pelletizing in the PR-7 press at i00-Ii0 N/mm 2 in the form of flat articles 460 mm and 520 mm long, with a cycle time of 26-30 sec. The pressed green brick had excess pressing cracks, an apparent density of 2.10-2.22 g/cm 3 in a monolithic piece, and possessed adequate strength for mechanized loading onto the kiln cars.The pellets were fired in tunnel kiln No. 6 at TsMI-2 (Magnezit Combine) at a maximum temperature of 1920~ and with 18 pushings of the car in 24 h, with a soak in the temperature zone above 1700~ of 10-11 h. The pellets were cooled in the range 1700-900~ using the standard cycle for the kiln at a rate of 70-72~The fired pellets were milled using the standard TsMP-4 scheme with screening to obtain respectively 73 and 27% fractions 3-I and I-0 mm (control weighing of powders). The open porosity of the pellet fractions 3-1 mm ...

show abstract

“…Taking into consideration the results of domestic [13][14][15] and foreign* developments, t~ose compositions of periclase--chromite materials which were characterized by increased…”

mentioning

confidence: 99%

Refractories for an argon-oxygen steel refining unit

et al. 1982

Self Cite

View full text Add to dashboard Cite

In recent decades such processes of outside-the-furnace refining of very low carbon steels as vacuum--oxygen decarburization, argon--oxygen decarburization, and steam--oxygen decarburization have obtained wide use. Vacuum-oxygen decarburization is done in the ladle and argon--oxygen decarburization and steam--oxygen decarburization in special converter-type units.In the USA, Japan, and the countries of Western Europe the most common are argon--oxygen decarburization converters, in which in recent years more than 70% of corrosionresistant steel has been made [i, 2].In the argon--oxygen deoxidation converter the semifinished product, melted in an electric furnace or other steel melting equipment, is treated by purging it with an argon--oxygen mixture supplied through several side or bottom tuyeres.During purging the temperature of the molten metal increases to 1700-1800~ and the slag is high chromium with a low basicity (~1.2). At the end of treatment of the semifinished product the chemical composition of the molten metal is adjusted by addition of ferroalloys and production of a highly basic slag. The average treatment time in an argon--oxygen decarburization converter is 90 min [3,4].The combination of high temperatures, the strong erosion action of the molten metal and slag, acid slags, and variable temperature loads presents very high requirements for the quality of refractories for the lining of argon--oxygen decarburization converters.In a number of countries the problem of refractories for the lining of argon--oxygen decarburization converters has been solved as a result of development of special magnesite--chromite parts from clinkers and melted powders with the use of pure SiO2 raw material and high firing temperatures (1750-1825~ [3-6].The average life of argon--oxygen decarburization converters of these refractories is 45 heats with a maximum life of about i00 heats [5]. Refractories with a high magnesium oxide content must be avoided since their life in contact with an acid slag was low (14 heats) [3]. In the parts of the lining which are most eroded (tuyere zone, slag area) cast periclase refractories possessed higher wear resistance than refractories from melted powders but as a result of their high cost and low heat resistance they have not found quite wide use in argon--oxygen converters [7,8].Substantial changes in the technology of the argon--oxygen decarburization process (a reduction in temperature, an increase in slag basicity, etc.) had made it possible to use dolomite refractories for argon--oxygen decarburization converter linings.The average life of a dolomite lining is about 60 heats [9, I0] and with the organization of intermediate repairs up to i00 heats [ii]. In Japan magnesite--chromite refractories with a weight content of 64-74% MgO and 15-18% Cr203 are used in the slag zone and magnesite--dolomite in a ceramic binder (78)(79)(80)(81)(82)(83)(84)(85)(86) in other portions of the lining [12].The authors of this article have made investigations of refractories for the lining of an a...

show abstract

Refractories based on fused pe riclase ? Chromite material for vacuum steel refining plants

Cited by 6 publications

References 0 publications

Thermomechanical and deformation properties of periclase and magnesia-spinel refractories

Thermomechanical and deformation properties of periclase and magnesia-spinel refractories

Refractories based on sintered and fused periclase-chromite

Refractories for an argon-oxygen steel refining unit

Contact Info

Product

Resources

About