Why use graphite electrodes? Advantages and defects of graphite electrode
By:Yvonne Sep 05, 2020
Graphite electrode is an important part of eAF steelmaking, but it only accounts for a small fraction of the steelmaking cost. It takes 2 kg of graphite electrode to produce a ton of steel.
Why use graphite electrodes?
Graphite electrode is the main heating conductor fittings of arc furnace. Eaf is the process of melting scrap from old cars or home appliances to produce new steel.
The construction cost of electric arc furnace is lower than that of traditional blast furnace. Traditional blast furnaces make steel from iron ore and use coking coal as fuel. However, the cost of steelmaking is higher and environmental pollution is serious. However, eAF USES scrap steel and electricity, which hardly affects the environment.
The graphite electrode is used to assemble the electrode and the furnace cover into a whole, and the graphite electrode can be operated up and down. The current then passes through the electrode, forming a high-temperature arc that melts the scrap steel. The electrodes can be up to 800mm(2.5ft) in diameter and up to 2800mm(9ft) in length. The maximum weight is over two metric tons.
Graphite electrode consumption
It takes 2 kilograms (4.4 pounds) of graphite electrodes to produce a ton of steel.
Graphite electrode temperature
The tip of the electrode will reach 3,000 degrees Celsius, half the surface temperature of the sun. The electrode is made of graphite, because only graphite can withstand such high temperatures.
Then turn the furnace on its side and pour the molten steel into huge barrels. The ladle then delivers the molten steel to the steel mill's caster, which turns the recycled scrap into a new product.
Graphite electrode consumes electricity
The process requires enough electricity to power a town of 100,000 people. In a modern electric arc furnace, each melting typically takes 90 minutes and can produce 150 tons of steel, enough to make 125 cars.
Needle coke is the main raw material for the electrodes, which take up to three to six months to produce. The process involves roasting and reimpregnation to turn the coke into graphite, the manufacturer said.
There are petroleum based needle coke and coal based needle coke, both of which can be used to produce graphite electrodes. "Pet coke" is a by-product of the petroleum refining process, while coal-to-coke is made from the coal tar that occurs during the coke production process.