Graphite electrode, mainly made of petroleum coke and needle coke as raw materials and coal asphalt as binder, is made by calcining, batching, kneading, pressing, roasting, graphitization and machining. It is a conductor that releases electric energy in the form of electric arc to heat and melt the furnace charge. It is mainly used for electric furnace steelmaking. According to its quality index, it can be divided into ordinary power, high power and ultra-high power Power.
The graphite electrode includes:
(1) Ordinary power graphite electrode
It is allowed to use graphite electrode with current density lower than 17a / cm2, which is mainly used in ordinary power electric furnaces such as steel-making, silicon smelting and yellow phosphorus smelting.
(2) Oxidation resistant coated graphite electrode
The graphite electrode is coated with an anti-oxidation protective layer (graphite electrode antioxidant). A protective layer that can conduct electricity and resist high temperature oxidation is formed, which can reduce the electrode consumption (19% ~ 50%), prolong the service life of the electrode (22% ~ 60%), and reduce the electric energy consumption of the electrode. The promotion and use of this technology can bring such 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 can save 373 (153 tons) electrodes per year and 16900 yuan per ton of ultra-high power electrodes per year, which can save 2585700 yuan.
② Graphite electrode consumes less electric energy, saving electricity consumption per unit of steel-making, saving production costs and energy saving!
③ Due to the less times of changing graphite electrode, the labor volume and risk coefficient of operators are reduced, and the production efficiency is improved.
④ Graphite electrode is a low consumption and low pollution product, which has very important social significance in today’s energy conservation and emission reduction.
This technology is still in the stage of research and development in China, and some domestic manufacturers have begun to produce it. It is widely used in Japan and other developed countries. At present, there are also companies specialized in importing this kind of anti-oxidation protective coating in China.
(3) High power graphite electrode. It is allowed to use graphite electrode with current density of 18-25a / cm2, which is mainly used in high-power arc furnace for steelmaking.
(4) Ultra high power graphite electrode. Graphite electrode with current density greater than 25A / cm2 is allowed. It is mainly used in UHP EAF.