BREAKAGES OF SODERBERG ELECTRODES DURING SUBMERGED ARC FURNACES START-UP

This article presents a technological issue related to the operation of self-baking electrodes in six-electrodes submerged arc furnaces during the process of smelting high-grade silicon alloys with iron and other elements by carbothermal reduction, carried out in Re Alloys ferroalloys plant. Particular attention is paid to technological problems related to the use of Soderberg electrodes during start-ups of electric furnaces after shutdowns. The impact of furnace shutdowns and starts-ups on thermal conditions disturbance of electrode sintering process, formation of microcracks, and thus deterioration of mechanical strength of the electrode leading to increased risk of breaking, is presented. Actual examples of electrode breaking during SAF start-up, causes of breaking, and possible ways to avoid them are described in the article.