EAFs

Electric arc furnaces (EAFs) are industrial furnaces that melt ferrous scrap metal or direct reduced iron by applying electrical arcs between electrodes and the metal charge. They are widely used for steelmaking and the production of specialty alloys. EAFs became practical with advances in electricity supply in the early 20th century and now account for a large portion of modern steelmaking, particularly where scrap availability is high or rapid capacity adjustments are needed.

A typical EAF consists of a refractory-lined vessel, an electrode assembly, a power supply, and refining equipment such as ladles and gas cleaning systems. The furnace can operate with alternating current (AC) or direct current (DC). DC furnaces, which use controlled rectifiers, can offer faster melting and lower electrode consumption but involve higher equipment costs. Charge materials include unprocessed scrap, baled scrap, direct reduced iron, and occasionally hot metal. The process involves charging, melting, refining (adjusting carbon content, alloying, slag chemistry), and tapping into a ladle for casting.

Performance depends on feedstock quality, energy price, and refining requirements. EAF heats typically range from several tens to a few hundred metric tons, with modern designs advancing productivity and energy efficiency. Environmental considerations include energy intensity, emissions tied to electricity generation, and air and slag gas cleaning; improvements focus on energy recovery, better insulation, and advanced emission controls.

Compared with traditional blast furnace–basic oxygen furnace routes, EAF steelmaking offers flexibility, higher use of recycled material, and lower capital costs for smaller to mid-scale operations, albeit with sensitivity to electricity prices and the carbon intensity of the power grid.