Consumption and use of electrodes in electric steelmaking
In electric steelmaking, the main raw material is scrap steel, the three-phase alternating current is used as the power source, and the current is used to heat and melt the charge bypassing the high temperature of an electric arc between graphite electrode and metal material, which is the main method for producing special steel and high alloy steel. At present, with the increasingly strict environmental protection, the electric furnace steelmaking also shows a strong competitive situation in the field of general steel – electrodes in electric steelmaking
As the conductive electrode of electric steelmaking, the graphite electrode plays an important role in supporting the stable operation of electric steelmaking. The graphite electrode in the center of the dc arc furnace is used as the cathode to add to the electric furnace, and the bottom electrode is the anode, which is composed of two horizontal metals. The metal plate is equipped with a gas-conducting cooling sheet, and many styli are attached to the metal plate. The stylus is filled with magnesia. Electricity flows through the horizontal metal plate at the bottom of the furnace into the contact pin, and then into the melting pool. This method has low consumption of steel-making electrode, which is only half of that of a three-phase ac arc furnace, low production cost, but it has advantages and disadvantages, among which the combination of graphite and magnesia brick is also easy to increase the carbon content.
Generally speaking, electrode consumption can be divided into the following categories:
Therefore, in the process of steelmaking, the consumption of electrode can be effectively reduced by reducing the consumption of oxygen, the consumption of sublimation, the occurrence of dissolution and spalling, the correct use of an electrode, the possibility of fracture reduction and the maintenance of electrode. At the same time, the application of new processes and new technology can also indirectly reduce its consumption.
The matching relationship between furnace capacity, transformer power load, and electrode size
In addition, electrode consumption is also related to electrode size, electrode variety selection, and operation mode selection to some extent. For example, if the electric furnace with the same furnace capacity of 120 tons is operated in the ordinary power electrode (RP) mode, the electrode consumption will be higher than the high-power (HP) and ultra-high power (UHP) mode due to the long smelting time. The surface area of the electrode can be reduced by selecting the electrode with the appropriate diameter, thus the electrode consumption per unit can be reduced.