Problems and solutions to protection of carbon-graphite electrodes

This paper presents literature review of the existing problems and solutions in protecting carbongraphite electrodes from the destructive environment of arc steel-making furnaces, magnesium and aluminum cells. The most significant publications on the corrosion resistance of cathodes and anodes in relation to physical, chemical, and electrochemical wear, to oxidizing environments, to active components of the introduction and destruction of the carbon structure are discussed. An analysis of various proposals and engineering solutions for reducing or eliminating the impact of aggressive environments on electrodes under specific operating conditions of metallurgical units is carried out. It was established that losses from lateral oxidation of the electrode surface of arc steel-making furnaces, when passing the temperature zone of 600–800°C, may reach 40–60% of the total consumption. Carbon-graphite products are subject to a significant destructive effect of the specific interaction of carbon with elements and compounds of the working environment, which can be introduced (intercalate) into the interlayer structure of carbon. The existing engineering and technological solutions mainly apply to the protection of the product surface; moreover, they perform their functions for a short time, rather than during the entire service life of the metallurgical unit. In this connection, it is proposed to focus on ensuring volumetric protection of electrodes from the effects of an aggressive environment. Intermediate results obtained in the field of synthesis of carbonbased composite materials adapted to the conditions of electrode production at existing enterprises are presented, along with the results of studies into the oxidizability of these composites. The existing and proposed engineering solutions for protecting the surface of carbon products have not received wide recognition or are not used in the metallurgical industry. Among the most probable reasons are the limited period of electrode surface protection, the complexity of reproduction, or the lack of profitability due to the high cost of protective components. In this regard, synthesis of C – TiC/TiB2 composite electrodes based on petroleum coke and graphite seems to be a promising research direction.