Practice of application of refractory concrete in industrial furnaces

The Teploograzhdenie Research-and-Production Company has developed refractory concretes with service temperature of 1150–1650°C which have been successfully used as car bottom lining in tunnel furnaces, block lining of the hearth and lower parts of thermal furnace walls (together with the Termostal’ JSC), lining of roof panels of a continuous furnace, and burner stones. __________ Translated from Novye Ogneupory, No. 11, pp. 18–19, November, 2006.     

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.     

Part 3. Phase Transformations within the Layer of a Dry Barrier Mixture for Aluminum Electrolysis Cells

It has been established that transformations within the layer of a dry barrier mixture (DBM) are selective in character and are mainly confined to the upper zones of the innermost part (core) of DBM. The DBM layer undergoes a solid-liquid sintering in these zones. The glass phase thus formed prevents the electrolysis products from penetration into the DBM layer. Modifier admixtures — titanium and iron oxides, products of electrolysis and degradation of the refractory layer AlF, SiF₄, and sodium oxide — decrease the viscosity of aluminosilicate melt. The grains of a disthene-sillimanite concentrate undergo cracking along the cleavage plane. Imperfections of the crystal lattice promote transformations in the grains of normal electrofused corundum. Oxyfluoride AlOF and an oxyfluoride of variable composition AlOF_{1 − x} are formed in the cathode lining of the electrolysis cell. For Parts 1 and 2, see Novye Ogneupory, Nos. 3 and 5, 2005. __________ Translated from Novye Ogneupory, No. 9, pp. 7 – 13, September, 2005.     

Composition and Fabrication of Magnesia Briquettes from Refractory Scrap for Repairing the Lining of Oxygen Converters

A technology for fabrication of refractory briquettes from spent periclase and periclase-carbon materials salvaged from decommissioned steel ladles has been developed. The briquettes can be used as a patching material to repair the worn refractory lining in oxygen converters. Tests of the patching briquettes were conducted at the MISW JSC with satisfactory results.__________Translated from Novye Ogneupory, No. 1, pp. 17 – 19, January, 2005.     

Economic aspects of dust collecting from exit gas and aspiration exhaust in refractory production

An economic concept of protecting the atmosphere from dust exhausts in refractory production is proposed. The efficiency of measures intended to decrease atmospheric pollution is considered at two levels: primary level — lowering the damage caused to the environment by decreasing dust exhausts: secondary — an integrated socioeconomic effect (improving the living standard of the population and increasing national wealth). A procedure is recommended for estimating the economic damage to company fixed assets caused by dust exhausts. __________ Translated from Novye Ogneupory, No. 7, pp. 63–65, July, 2006.     

Enhancing the reliability of the screw — nut friction couple of a friction screw press for refractories

Tribological techniques for enhancing the operational reliability of the screw — nut assembly of a 4KF-200 friction screw press for shaping refractory materials are considered. Economic and engineering effects due to the design modifications proposed are discussed. __________ Translated from Novye Ogneupory, No. 12, pp. 33–35, December, 2005.     

Periclase-Carbon Components for Use in the Refractory Lining of the Steel-Tapping Channel of a 370-Ton Converter

Tests of periclase-carbon blocks for the converter's steel-tapping channel available from the Kombinat Magnezit JSC were carried out in an oxygen-converter shop at the Magnitogorskii Metal-and-Steel Works JSC. The new refractory materials are shown to have a higher endurance as compared to the conventional periclase blocks, which made it possible to increase the operational efficiency of converters.     

Materials based on highly concentrated ceramic binding suspensions (HCBS). The effect of heat treatment temperature on the strength properties of siliceous ceramic castables

Mechanical properties of siliceous ceramic castables shaped by vibration and static pressing with binders of quartz sand HCBS (pure and with a 5% additive of refractory clay) are studied. Other conditions being equal the porosity and the strength of the materials is affected by the content of the binder (varied from 10 to 33%). Ceramic castables heat treated at 1200 — 300°C exhibit a compressive strength of 50 –60 MPa at a porosity of 12–16%. The effect of the porosity on the strength of the materials is analyzed.     

Fabrication of New Water-Soluble Chitosan Derivatives

A new water-soluble derivative of chitosan — chitosan oligoethylene oxide sulfonate — was synthesized. The ratio and concentration of reacting substances and temperature and duration of the chitosan modification reaction affect the composition and properties of the reaction products. The conditions that ensure a 100% yield of water-soluble chitosan derivatives were determined. Using potentiometric titration and IR spectroscopy, the formation of a new water-soluble chitosan derivative — oligoethylene oxide sulfonate — was confirmed. __________ Translated from Khimicheskie Volokna, No. 4, pp. 41–44, July–August, 2005.     

Experience Gained in the Service of a Zonal Lining for Converters at the Magnitogorskii Iron-and-Steel Works Joint-Stock Company

A brief report on the execution of a step of a program on improving durability of the refractory converter lining at the MISW JSC in 2001 is presented. The use of refractory components PUPK-1 (available from Kombinat Magnezit) and refractory components available from Meierton Co. in various campaigns is discussed.     

Improving Lining Resistance Using High-Magnesia Fluxes in the Converter Steelmaking Process

Tests carried out at the Severstal Joint-Stock Co. and Magnitogorskii Iron-and-Steel Works JSC showed that a lime-magnesia flux containing 30 – 35% MgO used in the converter steelmaking process produced a favorable effect on the refractory lining resistance. Compositions for high-magnesia granules (50 – 65% MgO) were developed, their properties characterized, and the rate of solution in the slag melt was determined. Using these granules in the converter process makes it possible to increase the service life of periclase-carbon refractories for converter linings.     

Use of polyester monofilaments in the connecting locks of drying screens — “clothing” for paper machines

Different types of frames for joining the ends of drying screens — “clothing” for paper machines were analyzed. A structure for connecting frames for modern fabric drying screens which totally correspond to the technological and service requirements was developed. The optimum types of connecting frames for drying screens include the end segments of the screen fabric forming the sewn flap and the ellipsoidal coil of thick polyester monofilaments mutually connected by a polymer rod. Nevskaya Manufaktura Joint-Stock Company, St. Petersburg. Translated fromKhimicheskie Volokna, No. 5, pp. 45–47. September–October, 1999.     

Isocyanates derived from fatty acids by the trimethylsilyl azide modification of the curtius rearrangement

Five fatty acid chlorides—myristoyl (14:0), palmitoyl (16:0), linoleoyl (18:2), oleyl (18:1) and stearoyl (18:0)—were smoothly converted in a one-pot, one-step reaction to the isocynates with one less carbon atom in the alkyl chain by treatment with trimethylsilyl azide in aromatic solvents at 100 C. The yields were consistently greater than 70%, and NMR and IR spectra of the products were consistent with the assigned isocyanate structures. “Interaction of Carbonyl Compounds with Organometallic Azides,” Part 3; for Part 2, see Reference 1; for Part 1, see Washburne, S.S., and W.R. Peterson, Jr., J. Org. Chem. 37:1738 (1972).     

The Steelmaking Ladle — Ways Towards Saving Heat

Using a program developed at the NLISW JSC, heat losses through the wall of a steel-teeming ladle for different types of refractory materials and lining design and the surface temperature of the ladle jacket are calculated. It is shown, both computationally and experimentally, that using efficient heat insulators for the wall lining of steel ladle, the liquid-metal outlet temperature in the converter can be decreased by 10 – 15°C.     

Silicon carbide refractory castables

Optimum formulations for castables intended for different service conditions are proposed. Silicon carbide castables containing ultradisperse particles of cement, silica fume, and electrofused corundum are developed. The castables do not weaken on heating and display superior operational properties: the compressive strength is 40–80 MPa at sintering temperature 400°C and 50–85 MPa at 1300°C, the strain onset temperature under a load of 0.2 MPa is 1700–1510°C; thermal stability (1300°C — water) is better than 45 heating/cooling cycles (1300°C — water); no change in linear and volume dimensions was observed on heating. The newly-developed castables can find application in various sectors of industry, in particular, as the refractory material for the lining of Whiting furnaces and porcelain kilns. __________ Translated from Novye Ogneupory, No. 12, pp. 36–39, December, 2005.     

Side-chain autoxidation of stigmasterol and analysis of a mixture of phytosterol oxidation products by chromatographic and spectroscopic methods

Although the structure of phytosterols is closely related to cholesterol, there is a gap in knowledge concerning the formation and occurrence of oxidation products from phytosterols. The main objective of this study was to isolate and characterize some side-chain oxidation products formed after autoxidation of stigmasterol. Another objective was to highlight the difficulties in the analysis of phytosterol and a mixture of their oxidation products by GC. Pure stigmasterol was oxidized at 120°C for 72 h in an air-ventilated oven. Preparative TLC separated the oxidation products, and the products were characterized with GC-MS and NMR. In addition to the common ring-structure oxidation compounds, three semipolar oxidation products—24-ethylcholest-5,22-dien-3β,25-diol, 24-ethylcholest-5,22-dien-3β,24-diol, and 24-ethyl-5,22-choladien-3β-ol-24-one—were characterized for the first time by TLC, GC-MS, and NMR. Moreover, the results of the analysis of a large number of oxidation products from sitosterol, campesterol, and stigmasterol by capillary column GC indicated that further efforts and optimization are required in this area.     

Al2O3 — TiO2 dispersion-strengthened granular refractory ceramics

The technology, properties, phase composition, and structure of Al₂O₃ — TiO₂ refractory granular ceramics are reported. Additional heat treatment provides conditions for generating nanocrystals and increasing significantly the ceramic strength. A dispersion-strengthening mechanism for refractory ceramics is proposed. __________ Translated from Novye Ogneupory, No. 5, pp. 36–39, May, 2006.     

The structure and chemistry of sulfatides

Recent advances in the chemistry of cerebroside sulfates which have led to a precise formulation of their structure and to a detailed knowledge of their composition are reviewed. Qualitative and quantitative analyses of the constituent fatty acids and sphingosine-type bases of cerebrosides and sulfatides have shown a close relationship between the cerebrosides and their sulfate esters. Sulfatides were converted into cerebrosides in high yield by mild desulfation with methanolic HCl at room temperature. The products of partial degradation of cerebrosides—ceramide and psychosine—were found to be identical to the products obtained under similar conditions from desulfated sulfatides. By methylation and periodic acid oxydation, the sulfate group has been located conclusively and apparently only at C-3 of the galactose moiety in the sulfatide molecule. Δ β-configuration of the galactosidic linkage in cerebrosides and in sulfatides has been demonstrated by direct comparison of the products of periodate oxidation of dihydropsychosine obtained from cerebrosides and from sulfatides, with the products of oxidation of 1-D-glycerityl β-D-galactoside of known configuration. Investigations of the composition and structure of sulfatides abnormally accumulated in the brain and kidneys in cases of metachromatic leukodystrophy, a demyelinating disorder, are reported.     

Carbon and carbon-containing refractory materials for blast-furnaces at the Chelyabinsk Electrode Plant Joint-Stock Co.

The effect of SiC additives and the granular composition on porosity, abrasive resistance, and endurance of carbon refractory blocks used in the blast-furnace steel-making technology. The use of microporous refractory blocks makes it possible to extend the blast-furnace production campaign by several years. The high efficiency of low heat-conducting cold-rammed mixes and a carbon-containing concentrate (available from ChEP JSC) is discussed.Translated from Novye Ogneupory, No. 6, June, 2004, pp. 16–18.     

Investigation of reaction in an Ni?Al?Cr SHS system based on high-temperature brightness pyrometry

A previously proposed model of reaction in an Ni−Al system is developed as applied to a ternary reaction system that is promising for obtaining materials for vapor-phase thermal deposition of protective coatings. We compare the features of the temperature profile of the combustion wave with data from structural investigations of the reaction products. We show that a detailed qualitative model for the reaction adequately fits the structure and phase composition of the products obtained over a wide range of concentrations of the alloying element (chromium) and initial synthesis conditions. Altai Scientific Center of Powder Technology. Altai Branch, Germes-Finans JSC, Barnaul 656099. Translated from Fizika Goreniya i Vzryva, Vol. 31, No. 5, pp. 52–57, September–October, 1995.