Graphite Electrodes

Graphite electrodes are mainly used in the production or recycling of steel. In this process, steel scrap is melted in a large crucible (furnace) by the heat of an electric arc, which is why these furnaces are called electric arc furnaces. Approximately 1/3 of the world’s steel is produced in this way, making it the largest recycling process in the world. In contrast to the alternative route, steel production by means of iron ore, production by means of electric arc furnaces avoids about 80% of direct CO2 emissions per ton of steel.

Such an arc is a channel of ionized air through which electric current passes from the electrode into the steel scrap. Something similar happens during a thunderstorm, here the current jumps over between the cloud and the ground.

In the steel mill, the crucible is loaded with steel scrap, then one strand (direct current furnace) or three strands (alternating current furnace) consisting of several graphite electrodes screwed on top of each other is introduced and then the arc is ignited. The arc is maintained for many minutes, so that the enormous heat of around 3500 °C generated quickly melts the scrap in the furnace. The molten steel is then poured off for further processing in a process known as tapping. Typical cycle times, i.e. the time between two taps, are between 45 and 90 minutes.

Such an arc is a channel of ionized air through which electric current passes from the electrode into the steel scrap. Something similar happens during a thunderstorm, here the current jumps over between the cloud and the ground.

In the steel mill, the crucible is loaded with steel scrap, then one strand (direct current furnace) or three strands (alternating current furnace) consisting of several graphite electrodes screwed on top of each other is introduced and then the arc is ignited. The arc is maintained for many minutes, so that the enormous heat of around 3500 °C generated quickly melts the scrap in the furnace. The molten steel is then poured off for further processing in a process known as tapping. Typical cycle times, i.e. the time between two taps, are between 45 and 90 minutes.

So why do the electrodes necessarily have to be made of graphite? If the electrodes that conduct the current were made of metal, as in almost all electrical devices, they would do likewise to the scrap and also melt. What is needed, therefore, is a material that can conduct the electric current well into the scrap, but does not melt even at the extremely high temperatures that occur in the arc. Our graphite meets precisely these conditions.

But despite its exceptional properties and the accompanying high resistance, the graphite electrode consumes itself in the melting process, mainly through oxidation. Therefore, at regular intervals, the shortening strand must be supplemented by screwing on a new electrode.

Our customers appreciate the low consumption values, high quality and reliability of our products. With production facilities in all regions of the world, we stand for short delivery distances and high delivery reliability in the industry.

More details needed?

Standard electrode sizes can be found here.