The rotating lance, tested in the CaO-Mg and CaC2-Mg processes,promotes a 20% and 30% increase, respectively, in the desulphurizationrate, a 50% reduction of temperature drop, and a reduction ofmetal splash occurrences. A criterion was developed that takes intoaccount the equipment dimensions and the mass flow rates of gasand desulphurization material, with the objective of transposing theresults obtained at Usiminas steel shop n°1 desulphurization station,to other industrial plants. Furthermore, it allows simulations to bemade with the objective of optimizing the pig iron desulphurizationprocesses that use the above mentioned materials as desulphurizationagents.