Electric Arc Furnace
An electric arc furnace (EAF) is a type of furnace used for steelmaking in which electrical energy is used to create sufficient heat to melt and refine steel scrap or other sources of iron into liquid steel. In an electric arc furnace, the primary energy source is converted into the formation of an electric arc between two electrodes, which serves to melt scrap or charge material in the furnace. The electric arc is generated by a power source, such as a generator, transformer, or rectifier. The electric arc is generally the primary source of thermal energy in the Electric Arc Furnace.
In general, the electric arc furnace makes use of three primary operational components: the furnace, electrodes, and charge material (or scrap). The furnace is usually constructed of mild steel or special alloy steel plates, which are structurally reinforced to create an effective barrier to thermal shock. The typical size of a modern electric arc furnace ranges from a few hundred to up to 3,000 tons. The electrodes, which provide the electric current to the furnace, are usually made of copper coated electrodes. The electrodes are typically supported by a series of hoists or lifting arms, which can turn and tilt the electrodes to improve the efficiency of the electric arc energy production.
The charge material used in an electric arc furnace is typically scrap steel, but may also include pig iron or direct reduced iron. The scrap steel or other source of iron is placed in the furnace, usually in a poured batch form, and then melted by the electrical arc. As the molten steel passes through the electric arcs, it passes through a series of zones, which vary in temperature and are used to control different aspects of the steel making process.
In the early stages of the process, intense heat is generated by the electric arc, which can be channeled to melt and refine the scrap steel. After melting, the steel is then refined via degassing, stirring, and oxidation. Also, the furnace can be used to adjust the chemical composition of the steel by adding alloying elements such as carbon, silicon, manganese, and chromium.
Once the refining and adjusting processes are complete, the molten steel is tapped out of the furnace and then poured into a ladle. The ladle is then used to transport the liquid steel to the steel finishing plants, where further processing is performed.
As one of the most advanced methods of steel manufacturing, the electric arc furnace has revolutionized the steel industry. By producing a wide range of steels in a cost effective and energy efficient manner, the electric arc furnace has become the primary method by which steel is made today.
