Goods based on refractory fibers are currently becoming more and more widely used [1]. One of the promising forms of such goods is refractory paper. Refractory paper is used abroad in various fields of engineering [2, p. 71; 3] because of its valuable physicochemical and engineering properties; the low thermal conductivity and thermal capacity; the excellent thermal-shock resistance; its ability to withstand the action of zinc and aluminum melts; good dielectric properties; etc. The operational temperature of the paper can reach 1150~ which is 500~ higher than asbestos paper.Research has established that the fibers in the sheet must be fastened together by bonding agents added to the paper composition, to produce a strong sheet.

Linings of heating equipment made with the use of refractory fiber thermal insulation materials are receiving ever increasing use. Their use makes it possible to significantly reduce the weight of heating equipment, heat losses to the environment, accumulation of heat by the lining, and fuel consumption and also to increase the productivity of heating equipment, especially batch furnaces such as bell furnaces.As a rule anchors of heat resistant steel, which are welded to the furnace shell by electric welding, are used for fastening of a lining of refractory fiber materials.The fiber materials are mounted on the anchors and fastened with metal or ceramic plates.Such a method of fastening of the lining requires the use of scarce heat resistant steel, a large volume of welding work, and the use of metal anchors through which the heat losses through the lining increase.Magnitogorsk Metallurgical Combine together with the Ukrainian Scientific-Research Institute for Refractories has developed a method of lining heating equipment with fiber refractory materials with an inorganic binder and the use of refractory cement.Thermal insulation fiber plates with a clay binder of unfired type MI

The aim of the investigation was to explain whether it is possible to obtain high-alumina cement from clinker calcined in shaft furnaces used for firing chamotte made from fireclays. The preliminary studies were done in small shaft furnace designed by the Institute.* The granules produced by the Dorogobuzhsk nitrogen fertilizer factory and prepared on a granulator at the Institute were fired in the trials.Together with adequate mechanical strength, preventing damage during firing in a shaft furnace, granules should have a uniform grain-size composition ensuring a uniform firing. The granules from the Dorogobuzhsk factory had a low strength and heterogeneous composition: there were marked variations in the apparent density of granules of the same size (with sizes of 15-20 mm it ranged from 1.3 to 1.6 g/cm3). Therefore we carried out a study to obtain granules with properties ensuring normal operation of the shaft furnace, It is known that the strength of moistened granules depends on their moisture content, and is determined by the forces of capillary action and surface tension of the thin water films, and the strength of the dried granules is provided by colloidal films of substances cementing the grains [i]. According to [2], good granulation occurs not only in finely milled materials but also in granular materials if they contain an adequate content of fractions minus 30 ~m, capable of enveloping the coarser grains.The granules were prepared from a mixture of unmilled alumina and finely milled chalk. The optimum moisture content of the batch was selected so that the granules were not broken down during operation of the granulator, and had a uniform grain-size composition. The granules with the maximum strength were those that had a moisture content of about 4%~In order to obtain seedings the mixture was moistened by spraying witha 2% solution of methyl cellulose and this was then passed through a screen with apertures of 2 ram; the rolling of the granules on the seeds was done with a mixture moistened through a jet using 25% solution of sodium lignosulfonate. The properties of the granules are shown in Table i. The strength of the raw granules rolled in the Institute was double that of the granules from the Dorogobuzhsk factory. The granules with the additions of surface-active substances have a somewhat higher density and strength. Such granules withstand loading in the furnace and firing without considerable damage.Both types of granule were fired in the shaft furnace. Since the Dorogobuzhsk granules had an irregular form and variable sizes, we selected granules measuring not less than I0 mm for calcination. The properties of the calcined granules are shown in Table 2 The Institute's granules calcined at 1450~ had a moderate concentration of calcium dialuminate, and after firing at 1600~ were mainly fused on to each other. The Dorogobuzhsk granules in the main were white in color, and some even at 1430~ were fused. Thus, the cal-*Designed for firing corundum briquet.

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The heat insulation of the hearth pipes of continuous heating furnaces is important because 15-35% of the heat input for heating the steel is lost with the cooling water [1]. The hearth pipes are insulated with various materials and by various methods~ The use of ceramic fibrous materials and products for this purpose is promising. These materials possess usefu[ properties like low density, thermal conductivity, and heat capacity and high thermal strength and elasticity, and they are convenient to use [2, pp. 87-92]. Numerous proposals have been put forward for the cQnstruction of the insulation of the hearth pipes with ceramic fibrous materials [3].The heat-insulation properties on water-cooled models were determined in tests with refractory fibers, with cardboard processed from high-alumina fiber, and with asbestos fabric bonded with a high-temperature adhesive.