Refining with Sulphur:

Sulphur is mainly removed as a sulphide dissolved in the slag. The sulphur partition among the slag and metal is based on slag chemistry and is favoured at low steel oxidation levels. Elimination of sulphur in the EAF is complicated. Most of the operations determine it more effective to carry out desulphurization throughout the dropping phase of steelmaking. It means that desulphurization is performed throughout tapping (where a calcium aluminate slag is made up) operations.

Control of the metallic constituents in the bath is significant as it find out the properties of the last product. Oxygen reacts with, silicon, aluminum and manganese to make metallic oxides, that are slag components. These metallics tend to react along oxygen before the carbon. They shall also react with FeO resulting in a recovery of iron units to the bath. For instance :

                                         Mn + FeO = MnO + Fe

Typically Manganese will be lowered to around 0.06 % in the bath.

The reaction of carbon along oxygen in the bath to generated CO is significant as it supplies a less costly form of energy to the bath, and performs various important refining reactions. Within EAF operations, the combination of oxygen along carbon may supply among 30 and 40 % of the total heat input to the furnace. Evolution of carbon monoxide is very significant for slag foaming. Coupled along a basic slag, CO bubbles are tapped in the slag causing it to "foam" and helping to bury the arc. It gives significantly improved thermal efficiency and permits the furnace to operate at high arc voltages even after a flat bath has been attained.

Also burying the arc helps to prevent nitrogen from being exposed to the arc where it may dissociate and enter into the steel.

If the CO is evolved in the steel bath, it helps to strip hydrogen and nitrogen from the steel. Bottom tapping is valuable for maintaining low nitrogen levels because tapping is quick and a tight tap stream is maintained. In the steel a high oxygen potential is beneficial for low nitrogen levels.

Decarburization is also beneficial for the elimination of hydrogen. This has been demonstrated that decarburizing at a rate of 1 % per hour may lower hydrogen levels in the steel from 8 ppm down to 2 ppm in 10 minutes.