South Ural State University, Chelyabinsk, Russia

G. D. Apalkova, Professor, e-mail: apalkovag@yandex.ru

One of the important characteristics of carbon materials, including side blocks, is the resistance to oxidation in gaseous media. Methods of protection against oxidation for carbon materials for various purposes, as well as methods and means for controlling their oxidizability, are analyzed. It is shown that for modern aluminum electrolysis the problems of ensuring the stability of the side blocks during the entire service life have been identified. For lateral blocks, oxidability as an actual physico-chemical characteristic is not standardized, and there is no separate methodology for its determination, taking into account the specificity of the side blocks in domestic practice. The international ISO standards are analyzed and it is shown that for the first time the definition of the oxidation of side blocks is highlighted in separate standards. This indicates the relevance of the direction studied in modern studies. A distinctive feature of the method for determining the oxidability of side blocks in international standards is the temperature at which this value is determined — 550 ^оС — against 900–950 ^оС for domestic methods of controlling carbon materials. The results of studies of the oxidizability of carbon side blocks and their components according to the modernized method are presented. The works on impregnating the side blocks with an environmentally preferable aqueous solution of antioxidant boron-containing compounds were performed. The mechanism of protection against oxidation is based on the formation on the surface and inside the pores of a barrier polymer film that limits the access of oxygen-oxidant from the environment to the material. Oxidability of impregnated blocks decreased by an average of 25%.

The article was supported by the Government of the Russian Federation (Resolution No. 211 of 16 March 2013), agreement No. 02.A03.21.0011.

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