The authors describe the results of developing compositions and technologies for barrier materials based on the products of concentration of kaolins from the Kampanovskii deposit for cathode lining in aluminum electrolyzes. High-density dry barrier mixtures with different Al 2 O-SiO 2 ratios (from 0.42 to 0.76) have been obtained, which can be used in two-layer linings for aluminum electrolyzers (in the high-alumina and silica layers). The composition and properties of these mixtures correspond to known foreign analogs.The service life and technical-economical parameters of electrolyzers producing primary aluminum to a large extent depend on the properties of refractoris used in cathode units, including barrier materials that serve as a barrier between the aluminum melt and the heat-insulating part of the electrolyzer base. Their main function is to lower the risk of emergency breakthrough of molten metal and electrolyte [1,2]. Such barrier materials in contemporary electrolyzers are either molded as bricks and plates, or non-molded in the form of dry barrier mixtures and concretes of different chemicomineralogical compositions, mainly aluminosilicates. It is assumed that when the electrolyte components penetrate into the barrier material, they react with aluminum oxides and form chemical compounds of the type of nepheline and albite, which creates an additional obstacle to further diffusion of chemically aggressive components into the electrolyzer base.In addition to this main function, i.e., after impregnation with electrolyte to form high-melting compounds whose melting point is higher than that of the infiltrating electrolyte (1100°C in the case of albite and 1200°C in the case of nepheline), the mixture of aluminosilicate powders redistributes the cross-section profile of the charge by decreasing it near the peripheral joints and making it higher in the central part of the cathode unit [3].Hence, it is evident that the main source of raw materials for barrier materials, regardless of their production method (molded or non-molded), are natural aluminosilicate rocks, i.e., refractory clays and kaolins. Despite the growing demand for special refractories to be used in electrolyzers, the Russian industry has not yet implemented the production of dry barrier mixtures (DBM); therefore, producers mainly use foreign refractory mixtures, most frequently from China.The present study evaluates the possibility of using kaolin from the Kampanovskii deposit to produce dry barrier mixtures similar in their composition and properties to imported DBM. According to standard requirements, all barrier materials based on their chemical composition are divided into two classes: high-silica (albite-forming), including grades MTDPR-2 and DBM, and high-alumina (nephelineforming), including grades E-50, E-53, E-55, and MTDPR-1 (Table 1). However, regardless of the DBM type, the Al 2 O/SiO 2 ratio in its chemical composition should be not more than 0.85 in order to provide high resistance to fluorides and aluminum melts.The need to de...
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