Periclase-carbon composite refractories with a new complex binder

We describe the development of the technology of periclase-carbon composite refractories with a new complex binder, which combines the properties of phenolic resins and coal-tar pitch. Theoretical analysis and the results of application in steel teeming ladle lining show that a combination of these thermoreactive and thermoplastic components in the new binder provides a more compact (denser) structure of the coke framework (residue) possessing increased resistance to oxidation. Articles made of the new composite refractory have been successfully tested in the lining of steel teeming ladles. The wear characteristics of new lining materials in steel ladles has been studied. __________ Translated from Novye Ogneupory, No. 8, pp. 14–20, August, 2007.     

Fabrication Of Periclase-Carbon Refractories With An Antioxidant And Their Testing In A Lining Of A 370-ton Converter

Periclase-carbon refractories based on electrofused periclase with an additive of passivated aluminum have been tested in service in the top cone of a 370-ton converter of the Magnitogorsk Metallurgical Works. The lining with experimental refractories withstood 1501 heats whereas the endurance of commercial periclase-carbon refractories of grades PUPK-6 and PUPK-8 equals 1185–1416 heats. It was concluded that the periclase-carbon articles with an aluminum antioxidant have good prospects for lining converters.     

Thermal Stresses Generated in the Lining of a Steel Ladle

Conditions for the thermal regime of 25-ton steel ladles lined with periclase-carbon refractories are analyzed. The input data for numerical analysis are the temperatures at the inner surface of the lining measured experimentally. Temperature profiles over the cross-section of the hot layer of the lining are calculated and then used to determine thermal stresses in the refractory material. A conclusion is drawn that sharp temperature gradients during the heating-up should be avoided. The currently employed heating regimes generate thermal stresses that exceed the strength tolerance limits for refractory materials. __________ Translated from Novye Ogneupory, No. 10, pp. 84 – 87, August, 2005.     

Upgrade of refractory lining of teeming ladles

A gradual upgrade of refractory lining of 160-ton teeming ladles, the disadvantages of the previous lining schemes, and methods for their elimination are described. The implementation of developed techniques has increased the resistance of teeming ladle lining by 60% (from 50 to 80 heats) and the consumption of refractory in the working layer of lining has decreased by 35.7% (from 4.79 to 3.08 kg/t of steel. __________ Translated from Novye Ogneupory, No. 7, pp. 18–19, July, 2007.     

Functional carbonized refractories

Functional carbonized refractories for the lining of steel ladles have been developed. Results of tests carried out on 400-ton steel ladles under industrial conditions are reported. The average durability of the refractory lining was 94.5 heats against rated value of 100 heats. __________ Translated from Novye Ogneupory, No. 7, pp. 34–38, July, 2005.     

The design and resistance evolution of 150-ton ladles lining

Under electric steel smelting workshop (ESSW) OAO Volzhskii Pipe Plant operating conditions the evolution of design and life of oxide-carbon refractories produced and supplied by OAO BKO in the period 2004 – 2008 is followed. Operation of the working refractory lining layer of 150-ton steel-pouring ladles of ESSW furnace-ladles is analyzed, and the main areas for improving refractory composition and lining design are determined. Translated from Novye Ogneupory, No. 1, pp. 5 – 14, January 2009.     

State-of-the-art plants for drying and high-temperature heating of ladles

The Stal’proekt Institute has developed state-of-the-art plants for drying and high-temperature heating of steel-teeming ladles. Two new plants for drying tundish ladle lining have been designed for machine No. 6 for continuous billet casting at the Oskol’skii Electrometallurgical Works. Plants for drying and heating 30-ton teeming ladles to a temperature of 800°C and for high-temperature heating of ladle lining (1200°C) have been designed for a currently constructed metallurgical works. All these plants recover flue gas heat and use it for heating air supplied for combustion, thus decreasing the consumption of fuel. The process of drying and heating of lining is analyzed using a mathematical model developed at the institute. The plants are equipped with automatic control systems controlling the temperature schedule of drying and heating the lining. The specified plants ensure cost-effective operation in an automatic mode __________ Translated from Novye Ogneupory, No. 10, pp. 21–25, October, 2006.     

Improvement of OAO BKO oxide-carbon refractories

Properties are provided for oxide-carbon refractories produced by OAO BKO, used for lining various zones of steel-pouring ladles and converters. The dynamics of lining life for a OAO NLMK 350-ton converter, executed with refractories produced by OAO BKO, are demonstrated.     

Ladle service under the conditions of vacuum-oxygen decarburization

The Izhstal plant has created a technology for treating corrosion-resistant steel by the method of VOD in a 30-ton ladle. The lining of the ladle is made of periclase-chromite refractories produced by the Magnezit Works JSC. The effect of the process parameters and lining patterns on the endurance of the ladle was studied in development of the process. The main factors determining the wear of the functional layer of the lining are the density of its joints, the composition of the slag of the refining period, the intensity of the mixing, and the thermal regime of the ladle between the heats. The pattern of the lining has been improved by reinforcing the slag line. The mixing regimes and the composition of the killing mixture have been improved where the consumption of lime and the proportion of aluminum to silicon are concerned. These measures have increased the endurance of the ladles by a factor of 2.2 and that of the refractory roofs by a factor of 2.5. Translated from Ogneupory i Tekhnicheskaya Keramika, No. 5, pp. 41–43, May, 2000.     

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.     

Effect of Process Regimes on the Life of “Mayerton” Linings in 385-Ton Steel Teeming Ladles

The effect of performance factors on the life of linings of large ladles from periclase-carbon (the slag-line area) and alumopericlase-carbon (walls) refractories is considered. The studied performance factors are the changes in the properties of the refractories upon heating, the temperature regime of melting, the chemical interaction between the lining and the slag, the residence time of metal in the ladle, the causes of emergency situations, and the effect of external factors on the topography of the lining wear. Observations of 114 ladles have shown that the lining life is determined by three groups of factors. Preliminary estimates made by the authors lead them to expect that a correction of some acting conditions of operation and maintenance of the ladles will increase their life by 10 – 12% without changes in the quality of the refractories or the design of the lining.     

Cast magnesia-spinel concrete linings for steelcasting ladles

Conclusions The magnesia-spinel concretes developed by the writers possess good mobility, thermal-shock resistance, volumetric stability, and low porosity. The concretes settle without additional compaction.A simple technology was developed for the production of cast concrete linings in steelcasting ladles. In transformer steel production the lining of 25-ton recasting ladles lasted six times longer than a chamotte brick lining and the specific consumption of refractories was four times lower; in 35-ton steelcasting ladles a lining of concrete MShG-15 lasted twice as long as a chamotte brick lining and the specific consumption of refractories was 1.3 times lower.An installation was devised for the production of cast concrete linings in steelcasting ladles.Translated from Ogneupory, No. 5, pp. 9–15, May, 1977.     

Testing MKB-75 mullite-corundum articles in linings of casting ladles

The West Siberian Integrated Iron-and-Steel Works has tested in 350-ton casting ladles mullite-corundum refractories of grade MKB-75 (TU 14-8-633-95) produced by the Semiluki Refractory Plant. The use of these refractories in the ladles for casting steel into molds provides an endurance of 40 heats without replacing the slag zone or the bottom, which is 1.5 times higher than the endurance of ladles lined with conventional KVKB refractories. The use of MKB-75 refractories for continuous casting is inexpedient because of the elevated specific consumption and low endurance of the refractories.     

Increasing the Durability of the Lining of 385-Ton Steel-Teeming Ladles

Data on the durability of the lining of steel ladles in service at an MISW ISC oxygen-converter shop are reported. The best stability of the lining under severe operating conditions was achieved using periclase-carbon refractories (since 2000, available from an in-home manufacturer at the MISW). The highest lining durability is found in periclase-carbon components composed of fused periclase (with MgO content not less than 96%) and coarse-grained graphite (7 – 10%).     

Development of a Technology for Manufacture of Periclase-Carbon Refractories

A technology for manufacture of periclase-carbon refractories for the lining of steel-teeming ladles of oxygen-blowing converter is developed.     

The Use of a Multiple-Purpose Lining of the Casting Ladle in an Integrated Steel-Processing Unit at the Oskol'skii Electrical Iron and Steel Works

A report is given on the production of periclase-carbon refractories using advanced technologies and raw periclase of different quality grade at the Semilukskii Refractory Plant Joint-Stock Company (SRP JSC). Refractories available from the SRP JSC were used at the Oskol'skii Electrical Iron and Steel Works JSC (OEISW JSC) to fabricate the multiple-purpose lining for casting ladles exploited in vacuum furnaces and integrated steel-processing units. The endurance of the lining for the walls and the slag zone of the casting ladle reaches 69 heats.     

Introduction of rammed linings for 250-ton steel-teeming ladles at Makeevka Metallurgical Combine

Conclusions In the open hearth shop of the Makeevka Metallurgical Combine the 250-ton steel-teeming ladles have been converted from a brick lining to a monolithic quartzite-clay rammed lining prepared with the use of a sand slinger using MKG-1 mixture according to Technical Specification 14-8-252-77 produced by the Krasnogorovka Refractory Plant. The use of monolithic linings of the ladle walls provided an increase in their average life from 9.06 to 15.6 heats.During service of the quartzite-clay rammed linings in teeming ladles partial degeneration of the quartz into cristobalite and full transformation of the fine crystalline binder into glassy occurs.The annual saving from the introduction of monolithic rammed linings of the 250-ton steel-teeming ladles of the Makeevka Metallurgical Combine was 2000,000 rubles.Translated from Ogneupory, No. 1, pp. 47–49, January, 1985.     

Unfired periclase-carbon refractories with a thermoreactive polymer binder

Elevated environmental requirements necessitate the development of new binders with a high carbon residue, heat treatment of which does not result in emission of toxic or carcinogenic substances. Such binders should have adequate technological properties. It is shown that it is possible to use a thermoreactive polymer binder based on a resorcinol oligomer for production of periclase-carbon refractories. The binder is soluble in water and organic solvents and possesses a high carbon residue (> 60%). Specimens of periclase-carbon refractories with the suggested binder and 5–12% graphite exhibit good ceramic and mechanical properties. Translated from Ogneupory i Tekhnicheskaya Keramika, Nos. 1–2, pp. 19–24, January–February, 1999.     

Increasing the number of uses of the refractories in the slide gates of large steel-teeming ladles

Conclusions A method of enrichment of brucite by washing and sorting of it was developed. An experimental lot of composite slide gate plates for two teemings from the 300-ton steel teeming ladles of Magnitogorsk Metallurgical Combine was prepared from enriched fused brucite at Magnesite Combine. The physicochemical indices of the plates were 97.9 wt.% magnesium oxide with a nonequiaxiality of the periclase crystals of 1.94, 0.3% silica, 0.2% iron oxide, compressive strength 110 N/mm², and open porosity 12%. Under conditions of repeated openings and closings the plates made it possible to provide 100% quality teeming of the first heat and to direct 60% of the slide gates to repeated teeming, which was done with 32%. For a final experimental verification it would be desirable to prepare a larger experimental production lot of refractories using the method developed with specific repeated use.Translated from Ogneupory, No. 2, pp. 47–51, February, 1988.     

High-strength periclase-carbon refractories based on phenol-formaldehyde resin with modification of different batch components

The production of periclase-carbon refractories based on phenol-formaldehyde resin with modification of different batch components is considered, which ensures a compression strength of 70–122 MPa. The strength is increased by reinforcing the resite structure by polysiloxane bonds. The synthesis of SiC in the service of refractories contributes to increasing the slag resistance of the refractory by being an additional antioxidant. __________ Translated from Novye Ogneupory, No. 7, pp. 52–55, July, 2006.