Desulfurization
Cast steel production

The extraction of sulfur from liquid steel necessarily involves the formation of stable sulfides. Thermodynamic data show the advantage of calcium sulfide (CaS) over other sulfides (MnS, FeS...). But calcium oxide (CaO) is also very stable. Desulfurization can therefore only take place by destabilizing the oxide (CaO) and creating thermodynamic conditions favorable to CaS precipitation (figure 13 ).