Carbon electrodes are applied for the production of silicon metal as they have peculiar characteristics. Carbon electrodes are used as electric current conductors in electric furnaces where silicon metal, elemental phosphorus or - to a small extent - other specialties are produced. The production of silicon metal and phosphorus is quite a specialised process and therefore only a small number of companies is engaged in this business world-wide. Most of the silicon metal produced is used in two main industrial fields: in metallurgy as an alloying element for aluminium and in the chemical industry for the production of a large family of plastics called silicones. Silicon metal is also employed, after a long processing chain, in the electronic field. 

Carbon electrodes play a main role in the production processes in submerged arc furnaces. Carbon electrodes are most largely used for the production of silicon metal. The process consists in the continuous reduction of quartz (SiO 2 ) into silicon by a reducing mixture according to the simplified relation SiO 2 , + 2C -> Si + 2CO. As components of the mixture, carbon in the form of mineral carbon, petroleum coke, charcoal, wood-chips can be used. The choice and proportions of these materials vary depending on the local availability and cost. The electric current runs through the electrode between the contact plates and the tip of the electrode causing the ignition of the electric arc with its extremely high temperatures (> 2000°C) necessary for the reduction of quartz into silicon. The silicon is then tapped from the bottom of the furnace. Every day, 15 to 50 tons of silicon are produced according to the power applied to the furnace. During the process the tips of the columns submerged in the reaction area are gradually consumed. Each of the three electrode columns is built with 5-6 electrodes.