It is shown to be promising to use ceramoconcrete technology in making refractory and heat-insulating materials. Research on these concretes has been done in industrial furnaces and plant. A new technology has been developed for gun-spraying of ceramoconcrete. Industrial tests have been performed and a technology has been devised for making large-block thermal-insulation components. Improvements have been made to the material as regards strength and thermal conductivity. Tests have been done on thermal-insulation ceramoconcretes in the lining of pouring ladles. The characteristics of ceramoconcretes are compared with those of traditional analogs.There are important lines in the scientific industrial activity of this organization in the development, testing, and implementation of new and promising materials. Efforts are devoted primarily of all to raising the quality of the materials and consequently increasing their working lives, and also the scope for reducing energy consumption.Recently there has been a substantial volume of research that has provided major results on the production of refractory and thermal-insulation materials on the basis of ceramoconcrete. Much experience has been accumulated in using dense ceramoconcretes in contact with molten media in magnesium electrolyzers and chlorators, as well as fluidized-bed furnaces and so on. Good results have been obtained in the development of a working lining, burner fittings, and pouring gullies made of ceramoconcrete in nonferrous and ferrous metallurgy (Figs. 1 and 2).Extensive use has recently been made of ceramoconcretes in furnaces for firing the anodes for the aluminum industry, where they have replaced traditional mullite refractories. A basic criterion influencing the working life of refractories in this furnace is the thermal stability. Table 1 gives the characteristics of IKBM-62 components made of ceramoconcrete by comparison with those of MLS-64 ones. Table 1 shows that ceramoconcretes have clear-cut advantages.In 2008, dense long and large-block components of ceramoconcretes were made for organizations in nonferrous metallurgy. In February 2009, industrial tests were completed on a new development at this organization: a technology for gun-spraying with ceramoconcrete. The unique properties of ceramoconcretes allow one to deposit them by gun spraying at an essentially new level. The material shows almost no shrinkage, and this avoids the formation of a large number of cracks, which had been assumed to be a normal phenomenon for a gun-sprayed surface. Also, there has been Fig. 1. Channel furnace under wagons for firing bricks (after two years of work).
Firing of aluminum electrolyzer anodes in multichamber furnaces of the open type is considered. On the basis of studying the thermal work of a firing furnace the main defects of furnace lining that arise during operation and the reasons for their development are studied. The effect of furnace construction on production of finished components from the point of view of quality, productivity, and correspondingly economic efficiency, is analyzed in detail.The most complex production process of manufacturing aluminum electrolyzer anodes is firing of the compacted "green" billets, as a result of which material should be obtained with the required physicomechanical properties, electrical conductivity, high mechanical strength and a uniform defect-free structure. The property indices required are achieved as a result of the maximum yield of coke residue and high quality of the sintering process. The quality of fired billets with uniform original properties after compaction depends on their firing conditions, the rate and uniformity of heat supply to the whole surface, the maximum heating temperature, and cooling conditions. The state of the firing furnace is of considerable significance.Firing is performed in chamber furnaces of the open type. Furnaces of this type are complex and very large heat engineering units, for example, the structure of a 72 chamber firing furnace has a lining volume of more than 14 thousand m 3 and it consists of more than 23 thousand tons of different refractories and heat insulating materials. The working layer of its lining is subject to mechanical, thermal and also chemical loads.A furnace is a unit of 64 or 72 chambers, arranged in two rows and between them connecting transitional (turning) channels for successive passage of gas streams from one chamber to another. Each of the chambers consists of 7 racks, having the shape of rectangular boxes bounded from the sides with partitions (flame walls), and over the ends by transverse walls, and from below by a furnace bottom. A rack serves as a vessel for loading anodes for firing.The partitions have internal channels for passage of furnace gases, that move successively over the partitions of six chambers, during firing. Transfer of gases from one chamber to another is accomplished through passage channels in the transverse walls. Due to brick bridges and vertical barriers, provided within the flame wall, there is sinusoidal movement of gas and uniform heating of the side surfaces of a heated barrier. Each rack has an automatic heating system accomplished by means of burners in each barrier. The overall form of a chamber furnace is shown in Fig. 1.The resulting thermal cycling technology for producing fired anodes includes heating of the flame partitions,
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