EAF

Electric arc furnace (EAF) is a furnace that uses electricity to melt metal by means of an electric arc struck between one or more graphite electrodes and the metal bath. EAFs are used primarily for steelmaking and for various ferrous alloys. They are characterized by high energy efficiency for melting scrap and their ability to adapt quickly to changing production needs.

Operation and feedstock: The furnace is charged with recycled steel scrap, direct reduced iron (DRI), or pig iron, along with alloys. As power is applied, an arc between electrodes and the charge heats the metal. Air or oxygen can be injected to aid refining, and fluxes form slag to remove impurities. The molten iron is refined, alloyed, and then tapped as steel.

Design and variants: Most EAFs use alternating current (AC) power with three graphite electrodes; direct current (DC) variants use a different configuration and one electrode arrangement to improve energy efficiency and electrode life. The furnace is lined with refractory brick, surrounded by a steel shell, with a separate refining station and tapping spout. EAFs can be built as large integrated plants or smaller "mini-mills" depending on feedstock and output.

Economics and environment: EAF steelmaking generally provides lower capital costs and shorter project timelines than traditional blast-furnace routes and is well suited to recycling. Its environmental impact depends on electricity source and process controls; benefits include lower emissions and flexibility, but handling electricity-intensive operations and scrap quality are important considerations. Ubiquitous in modern steelmaking, EAFs account for a large share of global crude steel production, particularly where scrap is abundant.