The promising and most accessible natural and technogenic raw materials are considered for lining metallurgical units for producing primary and secondary aluminum. A potential form of natural raw material for use as a dry barrier mix in aluminum electrolyzers is quartz pyrophyllite rock. For lining melting and casting units of the aluminum industry with the greatest technical and economic efficiency it is desirable to use aluminothermal slags and fuzed materials of OAO Klyuchevsk Ferroalloy Plant.The material sciences laboratories of OAP VOSTIO and NTTS Nonferrous Metals are carrying out a systematic search for new varieties of natural and technogenic refractory raw material suitable for preparing the linings of aluminum industry units; determination of its properties. The aim of this work is a reduction in the specific cost of refractories with sufficient wear resistance. Here a marked reduction in the cost of metal preparation is achieved by excluding expensive production conversion, i.e. high-temperature treatment of raw material and articles.A purposeful search for highly effective mineral raw material has been carried out taking account of the following main facts: melt resistance to reagents of metallurgical units, i.e. aluminum, cryolite, fluorite and mixtures of them; thermal stability under service conditions, i.e. absence of shrinkage, melting, corrosion, loss of strength, thermal spalling; economic capacity, i.e. possibilities for use without firing or fuzing raw material; ecological potential, i.e. absence of toxic and carcinogenic impurities in the raw material; accessibility, i.e. presence of reserves in mineral resources and dumps. A study was made of more than 40 varieties of natural and technogenic mineral raw materials of the Ural for their conformity with the suitability criteria listed above for the refractories of aluminum electrolyzers and melting and casting units. On the basis of comprehensive studies some promising raw materials were selected relating to the systems Al 2 O 3 -SiO 2 , CaO-Al 2 O 3 , CaO-MgO-Al 2 O 3 . Then from them pyrophyllite and aluminothermal slag were considered.Pyrophyllite. Among the numerous natural materials forming commercial deposits, there is most interest for producing aluminosilicate refractories in pyrophyllite Al 2 O 3 ·4SiO 2 ·H 2 O having refractoriness of 1710°C. The theoretical composition of the mineral is, wt.%: Al 2 O 3 28.3, SiO 2 66.7, H 2 O 5.0. The melting temperature is~1750°C.In view of the similar crystalline structure of pyrophyllite and talc many of their physicochemical properties are identical. Pyrophyllite has perfect jointing over plane (001), low hardness (about 1.0 of Moh's scale), a lamellar form of individual minerals, and a true density (specific gravity) of 2.8 -2.9 g/cm 3 . On heating, constitutional water is removed entirely in the range 600 -1000°C. The total dehydration product it metapyrophyllite Al 2 O 3 ·4SiO 2 . At 1150°C metapyrophyllite decomposes with formation of mullite and cristobalite. The overall sequence of phase ...

The substance composition, properties, and areas for use of five large scale varieties of technogenic high-alumina mineral raw materials are considered: aluminothermal slags, organic synthesis catalysts, abrasive slurries, aluminium slags and alumina dust. With combined use on the basis of this secondary raw material it is possible to produce more than twenty forms of different product:Currently in the Ural region a number of scientific organizations and industrial enterprises are participating in the fulfilment of Regional and Federal programs for processing technogenic formations. In 2008 the presidium of the Russian Academy of Sciences developed and approved a comprehensive program for study and assimilation of untraditional sources of mineral raw material, including technogenic formations. Main attention in the academic program is devoted to high-alumina natural and technogenic raw material sources: minerals of the kyanite, andalusite, silimanite, kaolinite and pyrophilite groups, aluminosilicate waste from thermal power engineering, high-alumina slags, slurries, dust, etc. Within the scope of fulfilling these programs there is research work, a study of substance composition and properties of mineral raw materials, and promising areas are being developed for use of the most valuable varieties of technogenic high-alumina materials. Among the latter are the following large-scale technogenic formations are of greatest practical interest (limits of Al 2 O 3 content, wt.%, are shown in brackets): aluminothermal slags in the production of the majority of ferroalloys and master alloys (50 -85), wastes of catalyst production or synthetic rubber (65 -75), corundum slurry from abrasive production (82 -96), dust from alumina calcining furnaces (90 -97), and metal-mineral waste from the production of secondary aluminum (60 -72).Technogenic "deposits" are primarily a potential raw material for synthesis of refractories, heat-resistant, and ceramic fuzed materials of different composition: alloyed corundum, mullite-corundum, spinel, codierite, etc. In view of the wide range of mechanical, thermal and chemical properties many varieties of technogenic mineral raw materials may be used effectively, not only in the refractory branch, but also in the production of abrasives, binders, heat insulation and other functional materials and objects [1 -3]. In order to develop effect areas for recycling secondary mineral resources complete information si necessary about the substance, grain size composition and physicochemical properties of each variety of technogenic polyphase and often polydispersed technogenic raw material. ALUMINOTHERMAL SLAGS FROM FERROALLOY AND MASTER ALLOY PRODUCTIONOAO Klyuchev Ferroalloy Plant is the sole enterprise in the RF and CIS producing more than thirty named unique ferroalloys and master alloys by the method of aluminothermal reduction of metals from oxides and other com-. 3 OOO Klyuchev Enrichment Plant, Dvurechensk, Sverdlovsk Region, Russia. 4 OAO UK RosStetsSplav, Yekaterinburg, Russia. 5 OOO NPO V...

Substance and grain compositions, parameters of physicochemical properties, and ranges of application of heat-resistant concretes produced on the basis of aluminothermic slags are presented. A wide range of fillers and lime-aluminate cements of refractory and heat-resistant concretes is considered. Experience in the use of slag concretes in linings of various heating units is described.

The results of an integrated study of high-alumina slag generated in the production of ferrotitanium, ferrochrome, and metallic chromium by the aluminothermic method at the Kluchi Ferroalloy Works are described. The chemical and mineral composition and refractoriness of the main varieties of slag are identified. The prospects for application of refractory slag are considered.The Klyuchi Ferroalloy Works is the only company in Russia and the CIS producing over 30 unique ferroalloys and alloying compositions using the method of aluminothermic reduction of metals from oxides and other compounds. Aluminothermic reduction of metals (Me) proceeds according to the following reaction: 2/m Me n O m + 4/3 Al ® 2n/m Me + 2/3 Al 2 O 3 .Consequently, in contrast to all other ferrous and nonferrous metallurgical slags, aluminothermic slag (ATS) is based on silica whose average content in the slag is at least 60 wt.%. The purpose of this study was to determine the mineral composition, microstructure, and physicochemical properties of the main ATS varieties and to issue recommendations for their more extensive application.

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