Graphite electrodes are mainly made of petroleum coke and needle coke as raw materials and coal tar pitch as binder. They are made by calcining, batching, kneading, pressing, roasting, graphitization and machining. They are released in the form of electric arcs in an electric arc furnace. The conductor that heats and melts the charge by electric energy is mainly used in electric furnace steelmaking. According to its quality index, it can be divided into ordinary power, high power and ultra-high power.
(1) Ordinary power graphite electrode
Graphite electrodes with a current density lower than 17A/cm2 are allowed to be used, which are mainly used in ordinary power electric furnaces such as steelmaking, siliconmaking, and yellow phosphorus smelting.
(2) Graphite electrode with anti-oxidation coating
Graphite electrodes coated with an anti-oxidation protective layer (graphite electrode antioxidant). It forms a protective layer that is both conductive and resistant to high temperature oxidation, reduces the electrode consumption (19%~50%) during steelmaking, prolongs the service life of the electrode (22%~60%), and reduces the power consumption of the electrode. The promotion and use of this technology can bring about the following economic and social effects:
① The unit consumption of graphite electrode is less, and the production cost is reduced to a certain extent. For example, a steelmaking plant, based on the consumption of about 35 graphite electrodes per week for the first-level LF refining furnace without production shutdown throughout the year, and the consumption of 165 refining furnaces, after using the graphite electrode anti-oxidation technology, 373 graphite electrodes (153 tons) can be saved every year. ) electrodes, calculated at RMB 16,900 per ton of ultra-high-power electrodes per year, which can save RMB 2,585,700.
② Graphite electrodes consume less electricity, save electricity consumption per unit of steelmaking, save production costs, and save energy!
③ Since the graphite electrodes are replaced less frequently, the labor and the risk factor of the operators are reduced, and the production efficiency is improved.
(3) High-power graphite electrodes. It is allowed to use graphite electrodes with a current density of 18-25A/cm2, mainly used in high-power electric arc furnaces for steelmaking.
(4) Ultra-high power graphite electrodes. Graphite electrodes with current densities greater than 25 A/cm are allowed. Mainly used for ultra-high power steelmaking electric arc furnace.