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).
Prospects are demonstrated for the use of heat insulation materials, manufactured by concrete technology, in various branches of industry. The materials are distinguished by thermal conductivity stability with a change in temperature, and high thermal shock resistance.One of the priority areas for the refractory laboratory of ZAO Soyuzteplostroi is development, testing and introduction of refractory materials prepared by ceramic concrete technology. There has been considerable experience of using dense materials in molten media (in magnesium electrolyzers and chlorinators, in fluidized bed furnaces, etc). Manufacture of ceramic concretes occupies two production areas of ZAO Soyuzteplostroi: in Bereznikoe of the Perm region, and in Lipetsk. It is planned to create two more areas in Angarsk and St. Petersburg.Currently there is intense work on creating medium-temperature heat insulating shaped blocks (900 -1200°C); there is a proposal for high-temperature objects. All of which assumes today either formation of objects of standard sizes or shaped objects, manufactured by technology of low or medium cement concretes. Since in ZAO Soyuzteplostroi there is a plant for producing expanded vermiculite, in order to manufacture heat insulating objects as a binder a HCVS (highly concentrated ceramic binder suspension) of aluminosilicate composition is used, and the filler is vermiculite.In the laboratory, and then in production, a new method for manufacturing objects has been proved and introduced. Whereas previously after moulding and drying of materials for providing the assembly strength of an object it was necessary to fire or strengthen it in an aqueous solution of water glass (strengthening by chemical activation of contact bonds) with additional drying, then currently a strong object is prepared after the first drying without additional introduction of an addition into its composition. This makes it possible to manufacture quite large objects with a thickness from 20 mm.Testing fro thermal conductivity of the materials obtained was carried out in the D. I. Mendeleev FGUP All-Russia Scientific Research Institute of Metrology. Specimens for testing had an apparent density of 0.9 g/cm 3 , a temperature on the hot side T hot from 30 to 600°C. Results of tests are
It is shown that the use of inexpensive, domestically produced refractory materials that have been produced according to the technology of refractories has shown promise for the manufacture of dry mixtures, runner clay and repair compounds, masonry mortar, and protective coatings. The dry mixtures are intended for the production of cast-in-place linings and large-block shaped articles with uniform structure that are resistant to corrosive media and exhibit high thermal stability. In terms of chemical composition, masonry mortar and protective coatings conform to the operating conditions. Following deposition on a working surface, the compounds used for hot repair experience a sharp rise in temperature.Refractory materials have been developed at the refractories laboratory of ZAO Solyzteplostroi based on the technology of ceramoconcrete for use in thermal power plants under different operating conditions. Considerable experience has been accumulated in the use of the newly developed articles in the chemical industry and in nonferrous metallurgy, in particular, in chlorinators, electrolysers and fluidized-bed furnaces in magnesium plants in the form of troughs and screens in the sector working with large billets, etc. The newly developed materials are used in the manufacture of coal-ash slag, cast-in-place furnace lining, and the lining elements of the trolleys of tunnel-type furnaces. Studies in the area of heat-insulating articles have also begun to find uses. The application of the technology of ceramoconcrete in the manufacture of refractory articles has made it possible to create serious competition to foreign analogs.The laboratory of ZAO Soyuzteplostroi was given the task of developing on the basis of this technology dry refractory mixtures with storage period up to 6 months in a hermetically sealed box that are technologically efficient for the manufacture of cast-in-place furnace lining and large and complexly shaped articles. The finished article must be resistant to melts of cast iron and slag, possess reduced wetting angle by melts and high thermal stability, mechanical strength, and refractoriness. Similar studies have been carried out at OAO Dinur under the scientific direction of Dr. (technical sciences) Yu. E. Pivinskii, and the newly developed compounds have already found applications. 3 In turn, specialists at ZAO Soyuzteplostroi, facing a critical situation, have attempted to reduce production costs through the use of inexpensive domestic raw material. Masonry mortar and repair compounds for hot repairs, supplied in both the dry and in the plastic state, have been developed.Refractory aluminosilicate crucibles in which the cast iron floats with slag obtained from OAO NTMK at 1500°C for 2 h have been developed for these purposes. The SiC refractory compound (brand F40) was added in order to reduce the wetting angle of the melt and, correspondingly, increase the resitance of the material. In its optimal composition, the compound contains Al 2 O 3 (³28%) and SiC (³15%). Following drying of the cruci...
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.