This research has been performed in order to study the effect of lime-based flux on simultaneous removal of phosphorus and sulfur from molten iron and also to investigate the effect of Na 2 O addition to flux composition as well as oxygen blowing into the melt on result obtained from the removal process. Experiments were carried out in the temperature range of 1350-1450 o C in an induction furnace with MgO refractory, using the hot metal produced at Isfahan Steel Co. obtained results indicate that simultaneous removal of phosphor and sulfur by lime-based flux is feasible. In addition, it was found that Na 2 O addition to flux leads to an increase in liquid phase and basicity power of slag, which improved the obtained results. On the other hand, oxygen blowing to the molten metal increase dephosphorization but tremendously decrease desulfurization due to increasing the oxygen potential. in the best conditions, highest amounts of dephosphorization and desulfurization 35 and 75 percent respectively, were successfully achieved. According to analysis of slag samples and experimental relations, it was found that silicon content of the molten metal has to be reduced to 0.15 percent prior to dephosphorization. Kinetic investigation of the process revealed that mass transfer in molten metal and slag phases and system’s oxidizing potential, respectively, are the most prominent steps in controlling the kinetic of process.
