Production technology for ladle brick using semiacid clays

Conclusions A technology was developed for making ladle brick from Ch1PK semiacid clays mined in the Chasov Yar area.The biggest difference between semiacid ladle brick and firebrick is the after-expansion at service temperatures of 1500–1600° C which reaches about 3% and which densifies the structure of the ladle.The life of semiacid brick in 250-ton steel ladles on average is 11% higher than ordinary ladle brick.The production of ladle brick from semiacid raw materials is economic. The lower cost of the product is a result of using cheaper raw materials and firing the clay into chamotte and products at lower temperatures.Translated from Ogneupory, No. 5, pp. 3–7, May 1967.     

Firing arkalyksk clays into grog and obtaining products from it

Conclusions We obtained heat-technical and technological factors for the firing of Arkalyksk clays in rotary furnaces.On the basis of grog made from these clays we obtained class-A articles.Ladle brick made on the basis of grog from Arkalyksk clay shows a resistance of 1–3 heats greater than ordinary ladle brick.Translated from Ogneupory, No. 7, pp. 33–40, July, 1966.     

Ladle brick from semiacid clays

Conclusions The main feature of the technology developed for the production of high-density ladle brick which expands in service, made from semiacid clay from Chasov Yar and Druzhkov sources, is the regular firing cycle for the chamotte and the finished products, namely completion of firing in the temperature range in which we can guarantee sintering of the material, but in which bloating has not yet begun.The life of the ladle brick in service made from semiacid clays is greater than that of high-chamotte ladle brick owing to the high density of the structural joints, governing the expansion of the working layer of the brick coming into contact with metal and slag.Mass production of semiacid ladle brick using the technology developed by VIO should be organized in refractory plants of the UkrSSR.Deceased.Translated from Ogneupory, No.2, pp.14–17, February, 1967.     

Conditions of operation of a tunnel kiln with injection burners

Conclusions The injection burners ensure jet combustion of the gas with the generation of an oxidizing atmosphere in the tunnel kiln. The firing of dense ladle brick and brick for blast furnaces in such kilns must last for 50–60 h.In discussion series [see Ogneupory, No.5, 11 (1968)].Translated from Ogneupory, No. 5, pp. 10–13, May, 1969.     

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.     

Making ladle products using North Onezhsk bauxites

Conclusions It was found that the North-Onezhsk bauxites are promising raw materials for the production of highly resistant ladle bricks.We developed and mastered a technology in the BKO conditions for making ladle brick using these bauxites containing up to 6% iron oxides.In the lining of the steel ladles made with the use of bauxite chamotte, the bricks wear out 30–40% less than with ordinary ladle brick produced by BKO and the Chasov Yarsk Combine.Translated from Ogneupory, No. 8, pp. 4–9, August, 1980.     

Siphon brick with high spalling resistance

Conclusions Production experiments establish the possibility of making port siphon brick with increased thermal shock resistance (spalling resistance) by the plastic method and pretreating the grains of chamotte with paraffin.The introduction of 2.7% by weight of commercial paraffin increases the usual spalling resistance factor of siphon brick by four times and greatly reduces its cracking service during thermal shock under the action of the jet of molten metal.An increase in the thermal shock resistance of the siphon brick with the introduction of paraffin in the batch is determined by the reduction in the thermal stresses on account of the lower coefficient of thermal expansion and modulus of elasticity. The effectiveness of using the method for increasing the thermal shock resistance was also confirmed by a number of other calculation characteristics.The positive results of the tests on the experimental siphon brick in service show the advantages of carrying out extensive testing of such siphon products, including those involving the casting of alloy steels.Translated from Ogneupory, No. 3, pp. 14–21, March, 1967.     

Increasing the life of ladle brick

Conclusions A technology was developed for the manufacture of ladle brick of high resistance. The difference between the proposed method and that used at present is in the increase in alumina content of the bond part of the batch. The nonplastic may be ordinary grog made of first or second-grade clays normally used in the manufacture of ladle bricks. The optimum Al₂O₃ content in the bond part of the batch is 55–60%.A compulsory condition for increasing the service life of the ladle brick, in addition to a high content of alumina, is the density of the bonding part of the batch. Therefore, the firing temperature of the goods should be determined not by the porosity of the finished product in general, but by the porosity of the bond part of the batch.The chief norms for the manufacturing technology are as follows: a) a batch content of 50–55% ordinary grog made of first and second-grade clays, water absorption not more than 5%; b) a batch content of 50–45% mixture of combined grist of high-alumina grog and clay; the ratio of grog to clay in the mix should be from 6535 to 7030.The conclusions of the present article have been proved by manufacturing an industrial batch of goods and testing them in linings of ladles [14]. The technology has been included in a project for reconstructing the Bogdanovich refractories plant.     

The influence of technological factors on the densification of forsterite green ware

Conclusions The grading of bodies made of dunite containing 20% additions of metallurgical magnesite ensuring a reduction in green porosity lies in the range 50–80% fraction 3–0.5 mm, 0–30% 0.5–0.088 mm and 20–50% finer than 0.088 mm.With an increase in fabricating pressure the relationship between the porosity of the green ware and grading diminishes.With a reduction in the grain sizes of the top and lower fractions the green porosity increases. An increase in moisture content from 4 to 6% in most cases increases the green porosity.An addition of 2–4% sulfite lye reduces the porosity (without a correction for pore filling by lye).The porosity of the green brick is greatly increased during firing. With the presence in the body of finely ground metallurgical magnesite the region of minimum porosity of fired specimens compared with the corresponding region for green brick moves to the side with the large content of fines.Dunite bodies with 20% fine magnesite giving the minimum porosity and shrinkage in firing should be used with the following grading: 10–40% fraction 3-0.5 mm, 10–40% 0.5–0.088 mm, and 50–70% finer than 0.088mm.An increase in the fines in the body leads to high shrinkage and deformation of the specimens in firing.     

Testing ladle brick made by various factories

Conclusions The resistance of linings in steel-casting ladles depends on the working conditions and the construction of the lining, the quality of the brick laying during repairs of the working layer, and the resistance of the ladle brick. The greatest effect on the wear of the lining in ladles is exerted by the following working conditions: chemical composition of the slag, temperature of the metal being cast, the dwell time of metal and slag in the ladle during one casting, the height of the slag layer in the ladle, the thickness of the lining in each belt of the structure. The quality of the structure in the ladles is mainly determined by the size of the joints, the care with which they are filled with mortar, uniformity of drying and warming-up of the ladles before filling them with metal.The resistance of the ladle brick depends mainly on the apparent porosity and nature of the pores and the concentration of fluxes and mullite in the brick.The highest resistance in service was shown by Zaporozh'e ladle brick made from Polozhe kaolin and having the lowest apparent porosity. The concentration of iron oxides in the brick was moderate, and on average equalled 1.39%.In terms of falling resistance the ladle brick of the remaining concerns can be placed in the following order: Chasov-Yar, Semiluks, Bogdanovich, Magnitogorsk, and Borovich.In order to increase the resistance of steel casting ladle linings it is necessary to increase the resistance of the ladle brick by reducing the apparent porosity, using raw materials with low concentrations of fluxes and improving the firing in order to obtain the maximum conditions of the ladle, reducing to a minimum the quantity of slag and reducing the casting time; to use a more rational thickness for laying the ladles over the courses, taking into account better use of their capacity.Translated from Ogneupory, No.5, pp. 27–32, May, 1970.     

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.     

Spinel-bonded magnesite brick for high-tonnage electric arc furnaces

Conclusions The manufacture of an experimental batch of spalling resistant magnesite-chrome brick with a spinel binder has made it possible to improve the technological norms for the production of these parts and has shown the possibility of making them at the new shop at the Magnezit Plant.The parts produced show good characteristics: refractoriness-under-load of 2 kg/cm² — 1650–1720°; additional shrinkage during heating to 1650° with subsequent holding for three hours –0.1%; spalling resistance 7–13 water-heating-cooling cycles (heating to 1300°); apparent porosity 15–17%; compressive strength 620 kg/cm².To obtain parts with good physical-chemical properties it is essential to use MK magnesite powder; to add at least 6–8% industrial alumina to the charge (in terms of Al₂O₃); to make certain the magnesite-alumina mixture is highly dispersed so that it helps to complete the spinel formation reaction during the firing; to use a mixture of the following grain composition: not less than 20% fraction 3–1 mm; 55–60% finer than 0.5 mm, including 30–35% finer than 0.06 mm; to press the parts at 1200–1500 kg/cm²; to fire the parts at a temperature not less than 1600°, batching them far apart so as to avoid the formation of an uneven structure.The use of magnesite brick with a spinel binder for the walls of high-tonnage electric arc furnaces used to melt transformer steel ensures satisfactory strength of the walls in the slag belt and prevents the steel becoming contaminated with chromium.     

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.     

Producing dense ladle brick with a kaolin bond

Conclusions The use of finely milled chamotte, triethanolamine, and bentonite in chamotte-kaolin batches considerably improves their moldability and sintering capacity, which enables us to obtain dense ladle brick with a porosity of 11–12% with a kaolin bond.Translated from Ogneupory, No. 4, pp. 10–13, April, 1972.     

Experience with producing ladle and blast furnace brick with a change in pressing rates

Conclusions A reduction in the pressing rate improves the factors of ladle and blast furnace refractories, since it affords the possibility of increasing the permissible upper limit for the pressing force, starting from the condition that there are no overpressing cracks.In order to obtain refractories with a low porosity it is desirable to prepare ladle and blast furnace brick with 5.0–5.5 pressings per minute with an average pressing rate of 9–11 mm/sec.Translated from Ogneupory, No.5, pp. 20–22, May, 1970.     

Service of refractories in the continuous casting of 100 ton converter heats

Conclusions Refractories for steel-casting ladles used at present in the converter shop of the Novolipetsk Factory can be used for casting 100-ton heats. However, it is necessary to increase the resistance of the ladle linings.Ladle bricks, stopper tubes, and zircon nozzles provide reliable casting of 3–4 heats in series without replacing the intermediate ladle.To provide reliable covering of the jets where necessary it is recommended that use be made of highalumina plugs for intermediate ladle stoppers.Translated from Ogneupory, No. 7, pp. 37–41, July, 1968.     

Semiacid ladle brick based on low-fired chamotte,quartz sand,and Ch1PK clay

Conclusions Dense semiacid products based on low-fired chamotte can be obtained by adding 15–30% quartz sand to the batch. The articles need to be fired at 1260±30–40°C. Firing at temperatures above 1300° and below 1230 even by 20–40° reduces the apparent density and after-expansion of the products.Preliminary testing in service showed that the wear of the semiacid ladle brick is 10% less than that of dense kaolinized brick.Using the proposed technology it is necessary to produce large batches of semiacid refractories, observing the optimum parameters of their manufacture in order to establish the economic effectiveness and advantages of organizing the industrial production of such articles.Translated from Ogneupory, No. 8, pp. 9–15, August, 1969.     

Mullite corundum refractories for out-furnace working and continuous casting of steel

Conclusions The Zaporozhe refractories factory has set up the industrial manufacture of mullite-corundum tubes using a technology developed by the Ukrainian Institute of Refractories together with the factory. The tubes are designed for continuous casting of steel and blowing it in the ladle at the Azovstal' Factory.Following improvements in the production method and increases in the resistance of the goods, it was possible to reduce the specific consumptions, and this gave a saving annually of 88,600 rubles.Translated from Ogneupory, No. 1, pp. 11–15, January, 1981.     

Change in properties of unfired magnesite tarred brick due to unilateral coking firing

Conclusions Unfired magnesite brick is capable of undergoing sharp thermal changes without visible signs of destruction.The rate of heating of the structure over the depth during single sided firing diminishes with time. The depth of coking of the tarred bond at 2 h firing reaches 140 mm and for 6 h firing 190 mm.The maximum compressive strength (430 kg/cm²) is possessed by a zone heated in the range 500–730°C. The apparent porosity and gas permability increase from the cold to the hot surface of the brick.     

Suitability of Zavadov deposit dolomites for use as raw material

Conclusions Investigations of raw Zavadov deposit dolomite showed that in strength it belongs to the dense varieties of dolomite with a fine crystalline structure. The weight % of the basic component (dolomite) is 88–98%. The impurities are calcite, quartz, clay particles, and iron oxides.By firing the dolomite in the form of the previously separated 5–25-mm fraction at 1700–1750°C it is possible to provide sintering of practically all of the samples. The use of preliminary grinding and briquetting improves sintering but does not provide significant advantages in comparison with firing in granular form. The addition of scale causes an improvement in sintering and an increase in the resistance to hydration.The resistance of hydration after firing at 1750°C in storage in air of samples Nos. 4–17 was satisfactory while the dolomite of samples Nos. 1–3 hydrated significantly more rapidly. With the addition of 1% scale and firing at 1700°C in storage in air the resistance is significantly greater.As the result of the investigation it was established that the dolomite, with the exception of individual samples, meets the requirements of Industry Standard 14-84-82 for raw metallurgical dolomite for patching and filling the sills of hearth furnaces and also for firing for metallurgical dolomite. A further improvement in dolomite quality is pssible with selective mining and benefication of it.Translated from Ogneupory, No. 2, pp. 36–40, February, 1987.