Guniting the lining of heating furnaces of rolling mills

Conclusions Guniting mass compositions and a procedure for guniting worn brickwork of continuous heating furnaces of rolling mills have been developed. At a number of metallurgical factories the worn brickwork of eight continuous heating furnaces of rolling mills have been repaired by guniting. The use of guniting enables the period between furnace lining repairs to be doubled (from 1 to 2 years), the volume of brickwork repair and the length of the repair work to be reduced, and a saving of 5000 rubles per annum per furnace to be obtained (merely by reducing the amount of repair work).Using IR spectroscopy the authors have investigated hydration and dehydration in alumina and high-alumina cements and aluminosilicate guniting masses with additives of these cements. They have shown that during guniting by the semidry method, hydration of the cements included in the composition of the gunite coatings does not go to completion and ends in the stage of formation of CaO·Al₂O₃·10H₂O; dehydration of the gunite coatings is completed below 300°C.Translated from Ogneupory, No. 5, pp. 30–35, May, 1980.     

Guniting the lining of steel-casting ladles

Conclusions In a joint investigation by the Serp i Molot Metallurgical Plant in Moscow and the All-Union Institute of Refractories the advantages were demonstrated of guniting the lining of steel-casting ladles. The first industrial-scale trials showed that guniting results in a significant increase in the durability of the lining and in a decrease in the consumption of ladle brick. In order to extend the practice of guniting steel-casting ladles it will be necessary to organize the production of gunite at specializing establishments of the refractories industry.Translated from Ogneupory, No. 8, pp. 37–39, August, 1975.     

Guniting slag belt in copper-refining furnaces

Conclusions A gunite mixture with a chrome-magnesite face base can be successfully applied and welded to the chrome-magnesite brickwork of the slag belt in copper-refining furnaces.Guniting the slag-belt lining is a reliable and effective method of prolonging its life and increasing the amount of time in between repairs.     

Guniting the lining of 300-ton steelcasting ladles

Conclusions The practice of guniting the lining of steelcasting ladles has been introduced for the 300-ton ladles of the open-hearth division of the Cherepovetsk Metallurgical Plant. The guniting parameters are as follows: the temperature of the lining of the ladle wall should be 60–120°C; the amount of wetting agent (sodium silicate solution) for the optimal adhesion of the G unite layer to the brick masonry should give the G unite mix a moisture content of 8–15%, and the density of the aqueous sodium silicate solution should be 1.15–1.30 g/cm³.The guniting operation is carried out with a remote-controlled centrifugal-action machine which permits the operation to be carried out at a temperature in the ladle of 200°C. The durability of the ladle lining increases significantly when the lining is gunited regularly up to five times per campaign. The estimated economic benefit from the practice of guniting the 300-ton steelcasting ladles is 85,000 rubles/yr.Deceased.Translated from Ogneupory, No. 2, pp. 29–32, February, 1978.     

Guniting of the monolithic lining of steel-teeming ladles

Conclusions The authors have developed the principles of guniting the monolithic lining of steel-teeming ladles with semidry masses. Determination of the wetting of a vitrified siliceous monolithic lining with aqueous solutions of additives and suspensions of these solutions, plasticizing additives, and refractory filler has shown that a coating can be deposited onto the surface of a monolithic lining. Formation of a ceramic bond between the coating and the vitrified surface of a monolithic lining takes place at high temperatures (900°C or above). Masses of siliceous, aluminosilicate, and periclase-chromite compositions have been developed for guniting the monolithic lining of steel-teeming ladles.A procedure for guniting the monolithic lining of 180- and 350-ton steel-teeming ladles has been developed and tested. The best results have been obtained with use of gunite masses of periclase-chromite composition.Translated from Ogneupory, No. 6, pp. 25–30, June, 1981.     

Highly refractory mixture for lining crucibles of induction furnaces for melting high-temperature steel

A dry corundum mixture for lining crucibles of induction furnaces of the powder metallurgy shop of the Dneprospetsstal' Plant that increases the durability of the lining in melting high-temperature powder steels is described. The economic effect of using the mixture amounts to 230,000 karb. per ton of melted steel.     

Guniting the roof of open-hearth furnaces during intermediate overhaul

Refractories and Industrial Ceramics -     

Refractory for lining induction furnaces

Conclusions Studies established that the lining body made from Karel'sk quartzites is not inferior to the Swedish material used for lining induction furnaces by many foreign companies.The great reserves and favorable mining conditions for obtaining these materials enable us to examine quartzite from the central Karel'sk area as raw materials for producing the lining bodies of induction furnaces.Translated from Ogneupory, No.5, pp.39–42, May, 1972.     

Refractories for lining blast furnaces

Conclusions At the Chasov Yar refractories combine we developed and introduced a technology for the production of chamotte kaolin refractories with a porosity of not more than 12% and a mass proportion of not less than 42% Al₂O₃ on the basis of chamotte from high-grade Polozhe kaolin, and also additions to the batch of finely milled mullite-corundum chamotte.Using the new technology we produced a batch of goods designated ShPD-42 for lining the shafts, bosh, and upper parts of blast furnaces of large capacity.Deceased.Translated from Ogneupory, No. 5, pp. 32–36, May, 1985.     

Guniting the roof of open-hearth furnaces at the Zaporozhstal' plant

Conclusions Laboratory analyses and industrial-scale tests resulted in the development of the technological parameters for guniting the lining of the main roof of 500-ton open-hearth furnaces operated at an accelerated melting cycle.The microstructure of chromite and chrome — magnesite coatings containing low-melting additives was analyzed and the chemical composition and structure of coatings which had served in the roof of an open-hearth furnace were determined.The work carried out at the Zaporozhstal' Steel Plant confirmed the effectiveness and advantages of guniting the roof of large-tonnage open-hearth furnaces.Translated from Ogneupory, No. 5, pp. 28–35, May, 1976.