Electric arc furnace are high-temperature furnace that makes steel with high-voltage electric arcs. Electric arc furnaces are a feature of minimills that produce new steel products by recycling iron and steel scrap.
An electric arc furnace is like a huge kettle that is lined with heat-resistant ceramic refractory material. There is a water-cooled lid that can be lifted off in the furnace for loading of scrap. Three graphite electrodes that create electric arc are held by the lid to melt scrap into new steel. Large electric lines enter the furnace. The lid inclines for loading. The lid is lowered and clamped tightly with the electrodes lowering into the scrap when the furnace is loaded. When power is supplied to the furnace, the electric power jumps from the two energized electrodes into the steel and passes through the steel through the neutral electrode connected to the ground. The steel scrap is melted by direct and radiant heat from the electric arcs.
Pulverized coal and oxygen are injected to supplement the electrical heat to obtain additional heat. Electric arc furnaces from the injection of fuel and oxygen produce approximately 35% of the heat. Accurately control additional energy to ensure that the finished steel has a carbon content that meets the level of the product.
