The electrode materials we use usually have many physical and chemical properties.
For example, the electric conductivity should be good, the resistivity should be small, so as to improve the power of the molten pool; then the melting point should be high; and the coefficient of thermal expansion should be small, when the temperature changes rapidly, it is not easy to deform, and the internal stress caused by the temperature change can not produce small cracks to increase the resistance; then, the high temperature should have enough mechanical strength; finally, the impurities should be low, and the impurities do not pollute the smelting products, etc.
According to the use and manufacturing process, carbon electrode can be divided into carbon electrode, graphite electrode and self baking electrode.
1： Carbon electrode is made of anthracite, metallurgical coke, pitch coke and petroleum coke with low ash content, which is composed of a certain proportion and particle size. The binder asphalt and tar are added in the mixing process, and then the carbon electrode is pressed and shaped after being evenly stirred at a proper temperature. Finally, it is slowly roasted in a baking furnace. It can be divided into natural graphite electrode, artificial graphite electrode, carbon electrode and special carbon electrode.
2： Graphite electrode is made of petroleum coke and pitch coke as raw materials, and is divided into ordinary power graphite electrode, which is mainly used in steel-making, silicon smelting, yellow phosphorus smelting, etc.; high-power graphite electrode is mainly used in high-power electric arc furnace for steel-making; ultra-high-power graphite electrode is mainly used for ultra-high-power Steel-making Arc Furnace.
3： The self baking electrode can be used continuously, and can be formed at the same time of lengthening. It can be baked into large diameter. It is made of anthracite, coke, asphalt and tar at a certain temperature. Then, the electrode paste is put into the electrode shell installed on the electric furnace. In the production process of the electric furnace, the Joule heat generated when the current passes through and the heat conduction in the furnace is carried out The process of sintering, coking and self baking electrode is not only simple, but also low cost. It is widely used in ferroalloy production.