Graphite electrode production line

　　Graphite electrodes are classified according to their current carrying capacity, flexural strength, compressive strength, density, resistivity, thermal shock resistance, coefficient of thermal expansion, and other indicators, as well as their applications. They are divided into four categories: Regular Power Graphite Electrodes (RP), Impregnated Graphite Electrodes (including graphite electrodes with antioxidant coatings and pitch-impregnated electrodes), High-Power Graphite Electrodes (HP), and Ultra-High Power Graphite Electrodes (UHP). In principle, different qualities of ultra-high power graphite electrode connectors are configured according to quality indicators for various graphite electrodes.

　 　1. Regular Power Graphite Electrodes (RP)
　　Regular power graphite electrodes are made from calcined petroleum coke or pitch coke as aggregate, mixed with a binder pitch, and then cooled, molded, baked, graphitized, and machined. Compared to high-power and ultra-high-power graphite electrodes, regular power graphite electrodes have relatively lower strength and bulk density, and can carry relatively smaller current densities. They are suitable for calcium carbide, industrial silicon, and small-current arc furnaces.
　　 2. Impregnated Graphite Electrodes (Graphite Electrodes with Antioxidant Coatings)
　　Antioxidant coatings are measures used to protect the electrodes and reduce oxidation. There are generally two coating processes: one is "impregnation" coating, and the other is surface coating. The graphite electrode antioxidant is a nano-ceramic material dispersed aqueous solution, which is a semi-transparent blue liquid. After the graphite electrode is impregnated under negative pressure or pressure with the antioxidant YHG-03, a high-temperature ceramic protective film is formed on its surface and in the micropores of its body, effectively isolating the air. This slows down the oxidation rate of the electrode, reduces the unit consumption of the electrode, and is an effective special antioxidant impregnant for electrodes. By introducing graphite electrode antioxidant treatment technology, electrode users can directly save about 15% of graphite electrode usage without any negative impact on the production site.
　　Impregnated graphite electrodes are mainly used in electric arc furnace steelmaking and the smelting of yellow phosphorus.
　 　3. High-Power Graphite Electrodes (HP)
　　Compared with ordinary graphite electrodes, in addition to adding some needle coke to improve the current density, strength, and density of the product, high-power graphite electrodes increase the impregnation and second baking processes, other processes are similar to ordinary graphite electrodes.
　　High-power graphite electrodes are mainly used in electric arc furnace steelmaking and chemical industry.
　 　4. Ultra-High Power Graphite Electrodes (UHP)
　　Compared with high-power graphite electrodes, ultra-high-power graphite electrodes use needle coke entirely. After adding one impregnation and second baking, the current density, strength, and density of the electrode will be significantly improved. Other processes are similar to ordinary graphite electrodes. Compared with ordinary and high-power graphite electrodes, ultra-high-power graphite electrodes, due to the use of needle coke entirely, have significantly improved flexural strength, thus being able to adapt to high-current impact and working conditions with high thermal shock resistance requirements.
　　 Brief description of graphite electrode production process:
　　Petroleum coke or pitch coke is calcined at 1250/1450℃. Calcined petroleum coke or pitch coke is used as aggregate, and after crushing, screening, and pulverizing, it is mixed and preheated in a kneading pot to the required temperature (corresponding to the properties of coal tar pitch). Then, heated and dehydrated liquid coal tar pitch is added for kneading. After that, it is cooled and molded into green electrode products. The green electrode products are baked under the protection of insulation material (shaping and preventing oxidation). To improve the strength and density of the product, impregnation and secondary or tertiary baking can be carried out if necessary. Then, after graphitization, it is finally machined into finished graphite electrodes (connectors) of the specified size.

　　 Graphite Electrode Process Flow Chart

　　Furnace types used: Calcination furnace, baking furnace, secondary baking tunnel kiln, graphitization furnace