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 can be divided into ordinary power, high power and power according to its quality index.
Graphite electrodes include:
(1) Ordinary power graphite electrode
It is allowed to use graphite electrodes with a current density lower than 17A/cm2, which are mainly used for ordinary power electric furnaces such as steelmaking, silicon making, and yellow phosphorus smelting.
(2) Coated graphite electrode
Graphite electrodes coated with a protective layer (graphite electrode agent). 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:
- The unit consumption of graphite electrode is less, and the production cost is reduced. For example, a steelmaking plant, based on the consumption of about 35 graphite electrodes per week in the first-level LF refining furnace without production shutdown throughout the year, and the consumption of 165 furnaces in the refining process, after using the graphite electrode technology, 373 electrodes (153 tons) can be saved every year. , calculated at 16,900 yuan per ton of power electrodes per year, which can save 2.5857 million yuan.
- Graphite electrodes consume less electricity, save electricity consumption per unit of steelmaking, save production costs, and save energy!
- Due to the less frequent replacement of graphite electrodes, the labor and risk factors of operators are reduced, and the production efficiency is improved.
- Graphite electrodes are low-consumption and low-pollution products, which are of great social significance in the promotion of energy conservation and emission reduction.
This technology is still in the research and development stage in China, and some domestic manufacturers have also started production. It is widely used in developed countries such as Japan. At present, there are also companies specializing in importing this protective coating in China.
(3) High-power graphite electrode
It is allowed to use graphite electrodes with a current density of 18-2/cm2, mainly used in high-power electric arc furnaces for steelmaking.
(4) Power graphite electrode
Graphite electrodes with current densities greater than 2/cm2 are allowed. Mainly used for power steelmaking electric arc furnace.
(5) Ordinary power graphite electrode
It is allowed to use graphite electrodes with a current density lower than 17A/m3, which are mainly used in ordinary power electric furnaces such as steelmaking, silicon making, and yellow phosphorus smelting.