Technology for high-alumina mortar in the Belokamensk Refractory Plant

Materials proposed for the production of a high-alumina mortar are investigated, namely, waste of melting of secondary aluminum, polishing powder of normal electrocorundum, and sintered corundum. A technology for the production of high-alumina mortars of three compositions has been developed for these materials. An experimental industrial batch of mortar composed of ShKN chamotte, polishing powder of normal electrocorundum, and DN2 clay has been manufactured and tested with a positive result. Production of the mortar has been introduced in the Belokamensk Refractory Plant.Translated from Ogneupory, No. 1, pp. 27 – 28, January, 1996.     

Selecting stable mortars for lining intermediate ladles of continuous steel casting plants

Conclusions The prolonged casting of killed carbon steel requires the use of high-alumina mortar VT-1, slaked with water; prolonged casting of rimmed and corrosive (manganese type) steels requires high-alumina mortar VT-1 slaked with orthophosphoric acid; the assembly of composite elongated nozzles in combination with batcher inserts for casting two or more heats of ordinary rimmed steels 08KP requires corundum type mortars (V-6).Translated from Ogneupory, No. 6, pp. 20–25, June, 1970.     

An Air-Setting Refractory Mortar Using a Composite Binder

A composite binder composed of water glass with a hardener and a high-alumina cement is used to prepare an air-setting refractory mortar based on fireclay fillers. The physicomechanical characteristics of the mortar are determined. An analysis of strains induced in the mortar under the first heat-up conditions with allowance made for the change in mortar's mineral structure is given.     

High-alumina mortar from scrap of refractory articles after use in metallurgical units

Scrap of refractory articles of grades MKS-72, MLKh-65, and ShKh-42 after use in steel-teeming and intermediate ladles of the OMK is studied. The possibility of using after-use scrap in the production of mortar is investigated. Experimental batches of high-alumina mortar have been produced and tested with positive results in linings of steel-teeming and intermediate ladles.Translated from Ogneupory, No. 5, pp. 28 – 31, May, 1995.     

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.     

High-alumina light weight brick and its use

Conclusions A production technique has been worked out for the manufacture of high-alumina lightweight brick by the combustible additive method with semi-dry pressing of the mixtures. These parts can be used for the working layer of the lining at temperatures up to 1550°.The long-term advantage of using high-alumina lightweight brick in the lining of fire-boxes for auxiliary boilers aboard ships using liquid fuel has been established. It is possible that this brick may be used in the future for lining the fire-boxes of the main boilers as well.To satisfy the requirements of the navy we must organize the production of high-alumina lightweight brick at the refractory plants of the South and East.     

如何驯服外墙装饰材料中的“野马”——装饰砂浆?

装饰砂浆是一种高性能、高装饰性、环保的建筑装饰材料,由于泛碱、开裂、色差等问题,约束了其在国内市场的发展。本文分析了装饰砂浆目前存在的技术难点与弊病,从产品定位出发,根据中涂砂浆与面层砂浆的性能特点,分别用硅酸盐水泥与高铝水泥作为凝胶材料,结合可分散乳胶粉与各类助剂对配方进行设计,结果表明:对装饰砂浆进行分类,区分产品性能特点,采用硅酸盐水泥作为中涂砂浆配方设计的主要凝胶材料,高铝水泥作为面层砂浆的主要凝胶材料,能有效控制装饰砂浆目前存在的问题。     

Refractories from kaolinitic materials and high-alumina bond

Conclusions In the department making high-alumina products at the Zaporozh'e Refractories factory they have manufactured an experimental-industrial batch of refractories with high thermal properties for building high-temperature zones of air heaters.The properties of the articles can be improved by fitting the department with powerful presses with staged pressing cycles.In the preparation of articles with a content of not less than 50% Al₂O₃+TiO₂ with a high-alumina bond, an effective method is to introduce commercial alumina together with fine grinding of the components. With this technology there is no need to prepare high-alumina grog which has to be crushed and ground.When organizing the industrial production of high-alumina articles using the proposed technology it is necessary to instal hydraulic presses with staged pressing with forces of not less than 1000 tons of powerful automatic friction presses, batching feeders, mixers SM-568, ensuring necessary vacuum treatment of the bodies, and high-temperature tunnel kilns with low settings.     

Production of high-alumina blocks for blast-furnace bottoms

Conclusions A hydraulic 1500-ton press is now used to produce high-alumina blocks 400×200×120 mm in size and 550×200× ×150 mm, in accordance with the specification for high-alumina bricks for large-size blast furnace bottoms. A technological system has been devised for manufacturing the blocks.The compressive strength of blocks 550×200×150 mm in size is about 100 kg/cm² lower than in the 400×200×100 mm blocks.Further improvement of the standard of high-alumina blast furnace blocks can be achieved by modernizing the 1500-ton press and adapting it for fine-grain mixtures, with a view to increasing the fraction finer than 0.088 mm in the mixture to 50–55%.     

Corundum wash for repairing carbon reactor linings

Conclusions We developed a body composition from electrocorundum and phosphoric acid. The body is well bonded to high-alumina refractories, and after heat processing has a high thermal-shock resistance and strength.The use of this body as a wash for the high-alumina (62% Al₂O₃) lining of reactors used in carbon production increases the service life by not less than 60%.Translated from Ogneupory, No. 3, pp. 27–33, March, 1969.     

Production of high-alumina cement clinker by fusion in an electric furnace

Conclusions The possibility of obtaining clinker from high-alumina cement by melting a mixture of lime and technical alumina in an electric-arc furnace at the Klyuchevsk Ferroalloy Plant has been shown.The high-alumina cement obtained from fused clinker is significantly better in its physicochemical properties than the cement produced on the basis of the lime-alumina slags from the ferroalloy industry.Translated from Ogneupory, No. 5, pp. 25–27, May, 1984.     

Production and properties of high-alumina ceramic concrete

Conclusions A high-alumina ceramic concrete containing ACBS based on the waste products of the high-alumina products industry and on a filler with D _s ^gr =2.5–15.0 mm of an analogous chemical composition has been obtained. The combination of studied properties suggests that new ceramic concrete shows promise for use in heat assemblies of various designs.Translated from Ogneupory, No. 2, pp. 54–56, February, 1982.     

高铝瓷的可塑成形

本文研究了全瘠性料高铝瓷的可塑成形。通过坯料可塑性和干燥性能的测定，对有机粘结剂进行了筛选。复合有机添加剂可以赋予高铝瓷坯足够的塑性和干燥强度。因为有机添加物的灰份接近于零，用它们增塑时，不会影响高铝瓷烧结后的结构与性质。     

碱土金属氧化物对高铝瓷烧结性能的影响

研究了碱土金属氧化物对高铝瓷烧结性质的影响，发现碱土金属氧化物增加高铝瓷韧性的同时并不降低其机械强度。加入不同的碱土金属氧化物其晶粒长宽比不同，一般来讲高长宽比的坯体有较高的韧性和机械强度及韦伯模数。     

Stress relaxation of foamed high-alumina cement paste

A series of stress relaxation tests on foamed high-alumina cement pastes with different relative densities under various temperatures and imposed fixed strains were conducted to study the effects of relative density and imposed strain on the stress relaxation rates of foamed high-alumina cement pastes. At the same time, the activation energy for stress relaxation of foamed high-alumina cement paste was determined from experimental results. Experimental results on the stress relaxation rates of foamed high-alumina cement pastes are also compared to a theoretical expression obtained from a cell-edge relaxation-bending model. Consequently, the microstructural coefficients included in the theoretical expression for describing the stress relaxation rates of foamed high-alumina cement pastes are found. Furthermore, the stress relaxation rates of foamed high-alumina cement pastes can be predicted from the theoretical expression once their relative density and the imposed strain are known.     

The protective layer and decalcification of C-S-H in the mechanism of chloride corrosion of cement paste

Two processes of the chloride corrosion of cement paste are discussed: decalcification of C-S-H and the formation of the skin on the paste surface. Decalcification is relatively quick in the magnesium chloride solution, and brucite as well as basic magnesium chloride are formed. Taylor pointed out the possibility of magnesium silicate hydrate, which was proved in the works of other authors. A skin is formed on durable mortars immersed in the strong chloride solution. It is composed of brucite and basic magnesium chloride. The protective role of this skin, as foreseen by Taylor, was temporary, and sooner or later, the skin was destroyed. The alkali activated slag (AAS) mortar became then quickly destroyed. However, in high-alumina cement (HAC) paste, the dense layer was formed near the surface, which protected the paste, thus hindering the corrosion process.     

Increasing wear resistance of stoppers for 140-ton steel-casting ladles

Conclusions Among the principal reasons for partial or substantial leaking of the metal stream are the following: burning away of the stopper, breaking off of the spherical part of the head, wear and tear of the head and sleeve bricks and opening up of the seams through deformation of the rod.The stoppers burn away on account of a great deal of wear and tear in the pipes, erosion of the seams, formation of cracks in the pipes and head and deformation of the stopper on account of the rod becoming too hot.The amount of slag in the ladle is one of the main factors for corrosion wear in stopper pipes. The aggressive action in the slag increases as the temperature of the metal and casting time are increased.Breaking off of the spherical part of the head during the first stopper opening due to the formation of skull between the stopper saddle and head can be avoided by using a graphite filling.Insulation of the stopper rod reduces the temperature during casting by 150–300°. The use of good quality mortar in assembling stoppers reduces the erosion of seams, while the use of a high-alumina putty prevents wear in the pipes.     

Glass-Migration Mechanism of Ceramic-to-Metal Seal Adherence

The basic mechanism of adherence in high-alumina ceramic-to-metal sealing has been studied. A sealing mechanism has been established which involves the migration of the glassy phase of the high-alumina ceramic into the interstices of the molybdenum-based coating. The study was conducted on 94 and 99% aluminas, using molybdenum-manganese, molybdenum-titanium, and pure molybdenum metallizing compositions. The possibility of the formation of chemical compounds by either the molybdenum or the added metals has also been studied. A means of isolating and identifying any reacted or migrated phases has been developed.     

A high-alumina mass for gunniting the lining of steel-casting buckets

Conclusions The composition for a high-alumina gunniting mass with an Al₂O₃ concentration of 65% was developed on the basis of chamotte obtained by firing the natural raw material. The production of the high-alumina gunniting mass was organized at the Semiluksk Refractory Plant.The process for gunniting 180-ton steel-casting buckets using the new gunniting mass has been mastered and introduced at the Novolipetsk Metallurgical Plant. An increase by 2.88 smeltings was achieved in the average resistance of the bucket linings with a once-only gunniting during the campaign.Translated from Ogneupory, No. 3, pp. 15–18, March, 1982.     

Composite nozzles for casting boiling steel in continuous steel-casting units

Conclusions A technology was devised for the manufacture of composite nozzles for casting boiling steel in continuous steel-casting units. The composite nozzle consists of porous chamotte nozzle (holder) and a high-alumina, magnesite or zircon liner (working part).The composite nozzles with high-alumina liners showed greater durability than other liners during the tests.