Ultrasonic quality control of ladle brick

Conclusions The relation was determined between the speed of USV and the open porosity of high-density ladle bricks containing a superduty refractory additive and produced by the Bogdanovich Refractories Plant.Calibration charts were plotted which permit the porosity of the various types of brick to be determined from the speed of ultrasound through the brick.Deceased.Translated from Ogneupory, No. 8, pp. 16–18, August, 1978.     

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.     

Results of a competition for the most resistant ladle brick

Conclusions The wear of the Chasov-Yar ladle brick was less than that of bricks made by the other factories; its average resistance for the five ladles was 13.3 melts.The average wear of the ladle brick made by the Zaporozh Plant exceeded the wear of the Chasov-Yar brick. The average resistance of this brick for the five ladles was 13.2 melts.The wear of the ladle brick made at the Belokamen Firebrick Plant is uniform, with only slight washing-out of the joints. The surface of the ladle after service was smooth and glazed.Examining all the materials tested during the competition the award panel awarded: first place in the compeitition to the Chasov-Yar Combine; second place to the Zaporozh Plant; third place to the Belokamen Plant.On the basis of material on the technology for the manufacture of ladle bricks used in the plants taking part in the competition, and also the service factors of the products during competitive testing, and on the basis of proposals from the All-Union, Ukraine and Vostok Institutes of Refractories for improving the quality of ladle brick, the award panel of the competition made the following recommendations for further improving the quality of ladle bricks:scientific-research institutes for refractories in collaboration with factory producers should carry out tests of fired ladle bricks made from chamotte and semiacid bodies, kaolinized and high-alumina raw materials and unfired products, and also should test linings made from rammed bodies in ladles of different capacities in different conditions of service;concerns should specialize in the manufacture of ladle bricks and install modern grinding, blending and pressing equipment;the assortment of bricks should be reexamined and the sizes of ladle bricks should be increased with the aim of reducing the number of joints in the structure;output of adequate supplies of high-grade special packaged mortars should be ensured.     

Making siphon and ladle products from Arkalyksk clay

Conclusions It is possible to use Arkalyksk clay in the bonding part of the batch in amounts of 3% for preparing siphon tubes with physicochemical properties corresponding to the requirements of GOST.With combined firing of experimental siphon tubes and ladle brick it was possible to increase the firing temperature by 50°C, as a result of which the porosity of the ladle brick drops 1%, and the wear 2–3 mm/heat. The experimental siphon tubes tested for casting steel had a satisfactory resistance.Translated from Ogneupory, No.2, pp. 1–3, February, 1970.     

Post-mortem analysis of MgO–Al2O3–C bricks containing bauxite used in steel ladle walls

A serious problem with integrated masonry linings ladle was that the ladle wall bricks were difficult to be partially replaced. Thus, the service life of the ladle was determined by the properties of ladle wall bricks. In this study, the new generation of MgO–Al₂O₃–C bricks with bauxite aggregates was tested in a ladle lining of an integrated steel ladle for 103 cycles, and the corroded microstructure of the used brick was investigated. A multilayered structure of bauxite aggregates could be observed in the used brick, which inhibited the slag penetration along the boundary of the magnesia aggregates and reduced the degree of the aggregates fall off from the used bricks. Besides, during the process of slag penetration, bauxite aggregates could melt into the slag, which increased the viscosity of the slag and weakened the penetration ability of the slag. The MgO–Al₂O₃–C bricks with bauxite addition could improve the service life of the ladle to a certain extent.     

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.     

再生镁碳砖和铝镁碳砖在精炼钢包上的应用

介绍了采用64%～88%质量分数的用后钢包再生料制造的再生镁碳砖和再生铝镁碳砖的性能以及在精炼钢包上的应用情况。使用结果表明,根据使用条件和再生料的特点,把镁碳砖的制造技术和使用条件结合起来设计制造的再生镁碳砖,其使用效果显著好于原镁碳砖:在300 t精炼钢包渣线上的使用寿命提高15%,在50 t LF-VD炉渣线上的使用寿命提高50%以上。     

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.     

Performance of a ceramic frit anti-oxidation coating on a MgO-C refractory brick

In steel production, ladles must be preheated to minimize the heat loss of the steel melt, prevent thermal shock of refractory bricks (MgO-C), and to maximize the lining life of ladle. Partial oxidation of MgO-C bricks begins in the graphite bond during the preheating. Oxidation of graphite bond also causes a decrease in performance of the bricks because of an increase in the brick porosity. In this article, coating on a MgO-C brick surface by a ceramic film to protect against carbon oxidation was studied. Coated and un-coated bricks were heated at 1200 °C, cooled to room temperature, then the brick properties investigated. The oxidization resistance properties of brick with coating were much better than those without coating, which should lead to longer refractory service life.     

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.     

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.     

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.     

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.     

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.     

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.     

Slag erosion-resistant coating for periclase-magnesia-aluminum spinel brick

The magnesia-carbon bricks are used at the ladle slag line adds carbon to molten steel and thus has an adverse effect on the smelting process. Steel production enterprises hope to remove carbon from the ladle slag line. This study presents a Silica sol (SS)–magnesium aluminate spinel(MA) coating that can be applied to the surfaces of periclase–MA spinel brick (spinel brick) to improve their slag erosion resistance, facilitating the elimination of carbon from the ladle slag line. The slag corrosion resistance mechanism of a spinel brick covered with the SS–MA coating was analyzed through scanning electron microscopy and simulation using FactSage software. The results show that increasing the SS content (C_SS) led to the formation of fine cracks during the coating-drying process and was detrimental to the slag erosion resistance of the coating. The optimum C_SS was 20%. In the high-temperature slag erosion experiment, the MA in the coating was capable of forming solid solutions with Fe and Mn in the slag, and the nano-SiO₂ in the coating interacted with the slag, increasing the viscosity of the slag and reducing its penetration. In addition, the presence of the coating extended the penetration path of the slag and reduced the contact area between the slag and the spinel brick and their chances to undergo chemical reactions, thereby protecting the spinel brick from slag erosion. The coated spinel bricks outperformed the magnesia-carbon brick in terms of slag erosion resistance, providing a basis for selecting carbon-free refractory materials for the ladle slag line.     

The wear of magnesia refractories in electric furnaces for melting cast iron

Conclusions The wear of magnesia refractories, i. e., magnesite, perictase — spinel, and magnesite — chromite bricks and magnesite — phosphate mortar, in the walls of electric furnaces for melting cast iron is the result of the solution predominantly of the periclase crystals and to a lesser extent of the spinel in the lowbasicity ferrosilicate slag melt. Brick of the PShS type proved to be the most durable refractory. The use of high-alumina brick in the roof of the furnaces accelerates the wear of the magnesia bricks in the walls.To increase the durability of the lining of these furnaces trials should be carried out with an all-basic wall lining constructed of high-density PShSP-type brick on MF-1-type magnesite — phosphate mortar and a roof lining constructed of MKhS brick and the same mortar.Translated from Ogneupory, No. 4, pp. 44–49, April, 1976.     

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.     

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.