South Ural State University, Chelyabinsk, Russia:

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

The properties of sidewall blocks should differ from the ones of hearth blocks, because they are not intended for current transmission. Nowadays, the main way to improve the technology for production of carbonaceous cathode blocks (including both hearth and sidewall ones), is to increase a part of artificial graphite in formulation (graphite-based blocks or graphite blocks) and a supplementary high-temperature processing of blocks by using electric power (grafitation; grafitated blocks). This ensures a decrease of specific electrical resistance ad increases thermal conductivity and thermal stability. Our paper shows the necessity and possibility to correct properties of sidewall blocks, which are not intended for current transmission. Investigation on influence of component composition on the properties of carbonaceous blocks based on traditional materials (thermoanthracite and graphite) shows that decrease of graphite level to 15% (in comparison with hearth blocks) enables optimization of their properties, that is, increasing of specific electrical resistance by 3 times. This allows for elimination of current losses through electrolyzer walls, increases the mechanical strength by 2 times, and decreases the heat conductivity by 4 times: all of this compensates the necessity in additional heatinsulated vermiculite plates. Taking into account the fact that both graphite and thermoanthracite are in different price category, decreasing the level of graphite reduces the production costs of sidewall blocks, which are thus able to compete with carbide-silicon plates. We made a review of globally popular modern methods and means of control of sidewall blocks. The importance of international standards of control is shown.
Our article is written with the support of the Government of the Russian Federation (Resolution No. 211 on 16.03.2013), agreement No. 02.A03.21.0011.

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