Electric steelworks

The arc furnace is essentially a tool for producing liquid steel from scrap, which can be partially replaced by cast iron or pre-reduced ores ( [28] and § 7.8 and § 7.9 ).

It consists of a steel vessel lined with refractories, and the necessary energy is supplied by electric arcs flying between graphite electrodes and the charge.

Molten steel is refined by reacting the liquid metal with a lime-based slag. The furnace lining is therefore basic 3.2 .

The smelting operation is often accompanied, or followed, by a decarburization and dephosphorization operation carried out by adding iron ore or blowing oxygen into the bath.

Decarburization is designed to bring the bath to the desired carbon content and, by releasing carbon monoxide, facilitates the elimination of dissolved gases.

Dephosphorization is achieved by oxidizing phosphorus and combining the resulting P ₂ O ₅ with slag lime.

After complete or partial removal (by overflowing above the gate sill) of the resulting over-oxidized, phosphorous-rich slag, the metal can either be ladle-cast for refining, or pre-refined in the furnace with powerful deoxidizers, such as silicon or aluminum, under a lime-rich...