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