Resistance of blast furnace refractories to the action of aggressive reactants under conditions of an oxidizing gaseous atmosphere

Conclusions Investigations have been made of the resistance of ShPD-41, ShPD-39, and ShUD-37 chamotte refractories to the action of K₂CO₃, Fe₂O₃, blast furnace dust, and initial and final blast furnace slags under conditions of an oxidizing atmosphere. The investigation results showed that iron oxides and slag break down these refractories at 1400–1500°C. Dense ShPD-41 refractory is more resistant to the action of the reactants.The most resistant to the action of slags and iron oxides at 1400–1500°C are silicon carbide refractories with binders of silicon nitride and oxynitride.Translated from Ogneupory, No. 7/8, pp. 24–27, July–August, 1992.     

Making refractory products from Arkalyksk clays

Conclusions With the use of Arkalyksk clay in existing conditions of refractories production at the ChMZ plant for obtaining grog with a water absorption of up to 5–6% it is necessary to add 25% plastic clay of the Buskul'sk type.The introduction into use of a rotary furnace will permit the firing of refractory Arkalyksk high-grade clays without additions, which should increase the life of the ladle and stopper refractories.     

Chamotte and semiacid ladle brick from Barzassk clays

Conclusions The Barzassk (basic O1 and O2, and semiacid PK1) clays are suitable for making chamotte and semiacid ladle brick. The production of refractories from these clays can be organized using the technological production scheme for chamotte articles made by semidry pressing. In order to increase the strength of the green products made from semiacid clays it is necessary to reprocess the bodies with an addition of sulfite lye on runner mixers with rollers.The resistance of the experimental chamotte and semiacid brick in a 300-ton ladle was practically the same as that of ladle brick made from Buskul'sk clay produced by the Magnitogorsk Metallurgical Combine.Translated from Ogneupory, No. 5, pp. 1–5, May, 1969.     

Differentiated use of refractories in blast-furnace hot blast stoves

Conclusions In the service of blast furnace hot blast stoves the lining and checkerwork fail in individual zones as the result of deformation of the refractories, formation of cracks, and chemical corrosion of the lining under the action of low-melting dust at high temperatures.It was shown that the deformation of aluminosilicate refractories depends not only upon temperature, load, and hold but also to a large degree upon the physicochemical properties of the parts, especially upon the composition and quantity of impurities.On the basis of an analysis of the service of refractories in hot blast stoves recommendations were developed on differentiated use of refractories in the different zones of the lining and checkerwork.For lining of the walls and the checkerwork of high-temperature hot blast stoves operating with a blast temperature up to 1300°C (temperature under the crown 1500–1550°C) the use of the following forms of refractories (GOST 20901-75) is recommended: 1550–1200°C temperature zone — type DV dinas parts; 1200–1100°C temperature zone — type MKV-72 mullite-corundum parts; 1100–900°C temperature zone — type ShV-42 chamotte parts; 900–700°C temperature zone — type ShV-37 chamotte parts; 700–400°C temperature zone — type ShV-28 chamotte parts.To line the lower portion of the combustion chamber mullite-corundum parts of types MK-80 to Technical Specification 14-8-405-82 or MKV-72 must be used.Lining of the crown, the inner wall of the combustion chamber, the hot blast lines, and the gas burners must be done with mortars corresponding to the types of refractories used (dinas and VT-1) with the addition of 10–12% orthophosphoric acid.Type MKRP-340 mullite-silica fiber parts to GOST 23619-79 and other fiber materials are recommended for use as the compensation gap filler up to temperatures of not higher than 1150°C, and asbestos-vermiculite plates to GOST 13450-68 in the up to 600°C temperature zone.The shell of the hot blast stove in the high temperature zone must be covered with thermal-insulation gunited concrete.Translated from Ogneupory, No. 7, pp. 44–50, July, 1986.     

钢铁工业用耐火材料的发展动向

结合当今国际钢铁工业的发展及其对耐火材料的要求，介绍了炼焦、高炉与出铁沟、熔融还原炼铁、铁水预处理、氧气转炉炼钢、高功率电炉与直流电弧炉炼钢、炉外精炼、盛钢桶、连铸中间包及近终形状连铸等的发展中，所用耐火材料的动向。     

Specialized spinellide-periclase refractories

Specialized carbon-doped spinellide-periclase refractories developed for the bottom lining of a ladle furnace are described. Large-sized PShUP 1-1-grade refractory blocks have been used for the impingement zone which made it possible to reduce the conventional wear rate of 6.21 mm per heat to 2.55 – 2.95 mm in the impingement zone and to 1.09 – 1.66 mm in the hot layer of the bottom lining.Translated from Novye Ogneupory, No. 9, pp. 30 – 33, September, 2004.     

Industrial tests of ladle refractories based on rocky olivinite of the Kovdorskoe deposit

The physicotechnical properties of ladle refractories based on rocky olivinite of the Kovdorskoe deposits, prepared by the technology of the St. Petersburg Institute of Refractories, are considered. Industrial tests of the experimental refractories in the lining of steel-teeming ladles of the open-hearth shop at the Cherepovtskii integrated iron and steel works have demonstrated that the attained durability of olivinite-containing lining (40 heats) exceeds 3.5 – 4 times the durability of conventional fireclay lining commonly used at the works. Rocky olivinite is a novel magnesia-containing raw material which should find wide use in the manufacture of ladle refractories.Translated from Ogneupory, Vol. 35, No. 1, pp. 27 – 28, January, 1994.     

Destruction of refractories by carbon monoxide at high temperatures

Conclusions Laboratory tests carried out showed that carbon monoxide at 500 ± 20°C destroys all types of refractories, regardless of their chemical and mineral composition with more or less substantial porosities. Destruction of the refractories occurs more rapidly the higher the porosity and the lower the degree of vitrification.Since the main cause of destruction in refractory in the shaft of a blast furnace is the action of carbon monoxide, the shaft needs to be lined with gas-impermeable refractories. The apparent porosity of the high-density high-grog refractory for the shaft of glass furnaces should be not more than 5–7%. With this density the refractory is practically gas-impermeable, and therefore is not destroyed by carbon monoxide. The optimum content of alumina in high-grog refractories should be considered as 35–37%.In the nature of a discussion. Comments on the articles by A. V. Gorokh and I. M. Galemina, Ogneupory No. 9 (1964).     

Low-iron bauxites of the Iksinskoe deposit

Iksinskoe-deposit bauxites (5 samples) with 65 – 75% Al₂O₃ were analyzed and used in ladle refractories which were tested in the lining of a ladle-furnace of a vacuum degassing plant. Their durability has turned out to be not inferior to that of mullite-corundum refractories based on commercial alumina.Translated from Ogneupory, Vol. 35, No. 1, pp. 13–17, January, 1994.     

冶金炉用喷补料的发展趋势

国外喷补料在产量逐年增加的情况下，致力于新材质、新品种的开发以适应不同冶金炉喷补的需要。随着我国喷补机的国产化，喷补技术已在高炉、焦炉、热风炉、转炉、电炉、精炼炉和钢包等处使用，使炉龄大幅度提高．今后应利用我国天然耐火原料开发多品种、新质量喷补料，研制喷补装备，以适应冶金工业的需要．     

Main causes of refractory wear in the shaft of a blast furnace and means of improving the resistance

Conclusions During service, refractories in a blast furnace shaft are saturated by components of the batch, change their properties and phase composition, and acquire a zoned structure which reduces the resistance to the complex action of the physicochemical and thermomechanical destructive factors.The wear of the shaft is a maultistaged cyclic process, including the saturation of the refractories through the pores, joints, and cracks by liquid and gaseous components of the batch and the gaseous medium, the decomposition of mullite and the formation of new compounds and glass — mainly potassium phyllitic and nepheline compounds — solution and reduction of the new compounds, and abrasion of the reaction products by the batch materials.We recommended for the lining of the shaft shoulders and the bottom and upper parts of the hearth the use of dense kaolin refractories containing 41–42% Al₂O₃ and with an open porosity of 8–12%, the technology for which is being introduced at the Chasov-Yar Refractories Combine.Translated from Ogneupory, No. 4, pp. 41–45, April, 1980.     

Unfired refractories bonded with coal tar pitch

Conclusions Medium-temperature coal tar pitches are effective bonds for making unfired dolomite and dolomite —magnesite refractories by pressing bodies heated to 100–120°C. The features of the refractories with a pitch bond are the higher contents of carbon resistant to oxidation (about 4%), and the higher compressive strength (400–500 kg/cm²), and finally the higher hydration resistance (10 days).Refractories bonded with pitch are much better than products containing tar, and accordingly offer a greater resistance when used in oxygen converter linings.Translated from Ogneupory, No. 3, pp. 6–15, March, 1971.     

Strength of magnesia refractories in combined thermal cyclic and mechanical loading of them

Conclusions As the result of laboratory tests of periclase-chromite refractories produced by different methods (MKhS, MKhV, and MKhVP) under the combined action of thermocyclic and mechanical loads possibilities were revealed of the most effective use of them in relation to the service conditions of plasma and electric arc furnace linings. The results of production tests of MKhS, MKhV, and MKhVP refractories at various furnace lining operating temperatures agree with the laboratory data and make it possible to draw the following conclusions:MKhS parts, as the most heat resistant, may be used successfully in heating the furnace lining working surface to 1700–1750°C, which corresponds to a temperature on the boundary of spalling of the refractory of 1400–1500°C.An increase in the lining operating temperature to 1800–1900°C (1550–1650°C on the boundary of spalling) requires the use of refractories with a combination of such properties as heat resistance and high-temperature strength. These requirements are met to the greatest degree by MKhV parts.In the future for large tonnage plasma and electric arc furnaces with high mechanical loads MKhVP high-strength parts may be recommended for the lining. However, for successful use of these parts it is necessary to aim to increase their heat resistance.Translated from Ogneupory, No. 5, pp. 43–47, May, 1985.     

Damage to stoves and measures to eliminate it

Conclusions As a result of investigations into newly developed refractories and a study of their service conditions in the stoves of blast furnaces, three basic types of failure in the structure and the checkers were determined:the formation of vertical cracks in the dome and walls; deformation of the checkers and the upper part of the combustion chamber; and failure of the lower part of the combustion chamber. The formation of cracks can be eliminated by selecting the optimum joints, and by using a design in the stoves which takes into account the properties of the refractories under variable temperatures.In order to reduce the deformation of the checkers and the combustion chamber it is recommended that these zones be made of refractories possessing the minimum creep, in the first case dinas with low embrittlement factors, and high-alumina products made of kaolin and calcined alumina.The lower part of the combustion chamber should be built from high-alumina and kaolin refractories possessing a high resistance to thermal shock.It is found that the upper rows of the checker become saturated with fusible compounds, formed when batch dust falls on the material, which means a substantial reduction in their thermal-mechanical properties, contributing to an increase in the deformation under load.To increase the blast temperature to 1300–1400°C it is necessary to use, in the high-temperature zones, mullite, mullite-corundum refractories based on kaolin, and low-embrittlement dinas with the compulsory completion of a number of measures: installation of an emission combustion chamber, removal of the dome load from the working walls, the use of perforated checkers, the construction of a special device for putting the furnace on draft, purification of the gases and air to remove dust and fusible substances, a reduction in the heating period, and the organization of paired-parallel operation of the stoves.Translated from Ogneupory, No. 1, pp. 23–32, January, 1972.     

Investigation of Taimyrsk graphites for producing periclase-carbon ladle refractories

Conclusions The investigations showed that Taimyrsk graphite corresponds in chemical composition to foundry and crucible graphite.The content of crystalline graphite equals 13.0–26.3%. The characteristics of periclase carbon goods based on foundry and Taimyrsk graphites correspond to the demands placed on ladle refractories. The wear factors of these products in the slag belt of the lining of 350-tonne steel ladles are on practically the same level.Taimyrsk graphites may be used for the production of periclase-carbon ladle refractories in place of crucible or foundry graphite.L. N. Kurlyandskaya (Urals Geology Planning Association) and L. Ya. Osipova (All-Union Institute of Refractories) took part in this research.Translated from Ogneupory, No. 1, pp. 15–17, January, 1991.     

Checker blocks for blast-furnace stoves

Conclusions A design was developed and introduced into production for a mold suitable for making perforated blocks for the checkers of blast furnaces by the semidry method on a redesigned SM-143 press. It was demonstrated in principle that it is possible to use the semidry method for pressing chamotte perforated blocks grades VShA and VShB, using a technology employed for manufacturing stove refractories for blast furnaces.The production technology should be tightened up if the products are to have stable strength, porosity, and after-contraction factors (product grade VShA). The technical requirements for the finished products in terms of spalling resistance require reexamining to take into account the shape of the specimens.Translated from Ogneupory, No. 4, pp. 6–9, April, 1971.     

Berlin clay as binder for chamotte products

Conclusions A. technology was developed and introduced for the production of ladle and steelcasting refractories bonded with a mixture of 75% Berlin clay and 25% Arkalyk clay.The durability of the ladle lining was 1.5 melts higher when constructed of this brick.Translated from Ogneupory, No. 7, pp. 4–6, July, 1977.     

A Technology for Production of Composite Refractory Materials for the Lining of Steel Ladles

Results of the testing of new refractory materials for the lining of steel ladles are reported. Refractories based on coarsely crystalline periclase (98% MgO) for the slag zone with an endurance of 55 – 60 heats and wear rate of 2.3 mm/heat were tested. For the bottom lining of the steel ladle, alumina-periclase-carbon refractories using fused or sintered alumomagnesian spinels are developed. Performance characteristics of the newly developed refractory materials are discussed.__________Translated from Novye Ogneupory, No. 1, pp. 6 – 9, January, 2005.     

Reaction between refractories and slag and oxidizing steel

Conclusions Scale, removed from the lining of a heating furnace reacts weakly at 1200–1450°C with corundum, high-alumina, chromite, chrome-magnesite, forsterite, and carborundum refractories.Directly in the process of formation, the scale reacts actively with corundum, high-alumina, chromite, forsterite, and chrome-magnesite refractories, and adheres strongly to them. Carborundum refractories in an oxidizing atmosphere at 1200–1500°C are not wetted and do not react with the scale and the oxidizing metal.Under experimental oxidizing conditions, corundum refractories with zero porosity must be considered to be the most resistant to the action of the scale immediately after its formation.Translated from Ogneupory, No. 4. pp. 23–28, April, 1968.     

Plugs and nozzles for intermediate ladles in continuous steel casting with automatic jet control

Conclusions We prepared and tested in service refractories satisfying the requirements of automatic casting from the intermediate ladle in continuous steel-casting plants. The high-alumina conical plugs and unfired magnesite inserts fixed to fireclay nozzles can be recommended for further use.Translated from Ogneupory, No. 1, pp. 32–35, January, 1970.