EAF Unit in Donawitz: Installation Is Underway

With every component installed, the overall picture of the new production line becomes clearer. The two electric arc furnaces have now taken on a distinct shape. If you look closely, you can already make out the electrode support arms of the furnaces.  

What exactly is their function?

Extremely high currents enable the electric arc furnace to melt the feedstock. Three large graphite electrodes generate an electric arc that reaches temperatures of up to fifteen thousand degrees Celsius. The electrodes are powered by the three phases of the electrical grid and together form the furnace’s central melting system. The energy generated in this process efficiently liquefies the feedstock and prepares it for further processing.

Which materials are melted in the EAF using the electrode support arms and enormous amounts of electricity?

• Steel scrap: The most important raw material for the electric arc furnace. This consists of processed scrap steel from industry, manufacturing, or recycling.
• HBI (Hot Briquetted Iron): Sponge iron material compressed into briquettes with very high purity. HBI is used to specifically improve steel quality and ensure a consistent chemical composition.
• Alloying elements and additives: These are added as needed during the melting process. They include, for example, lime, dolomite, carbon, and various alloying elements such as chromium, nickel, molybdenum, or manganese, depending on the desired steel grade.

The furnace itself consists of a multitude of complex components. The central components of the electric arc furnace—including the lower vessel, upper vessel, and furnace cover—have already been installed. The heavy-duty assembly of the rotating towers, including the lifting cylinders and electrode arms on both electric arc furnaces, has also been successfully completed. As essential parts of the plant, these components will perform key functions in the melting process and, together, form the central melting unit of the new production line.

Work has also been underway on the scrap transfer cars, where a variety of welding tasks have been carried out. Once the plant is operational, these cars will transport the scrap from the scrap yard to the EAF unit. The scrap is transported in scrap baskets via an underground conveyor system all the way to the furnace hall. The scrap baskets intended for this purpose have already been fully assembled and positioned on the scrap transfer cars. This marks the completion of another important step toward the future material supply for the electric arc furnaces.