Abstract
The effect of temperature, silicon and manganese in carbon-saturated iron (0.1%P, 0.05%S) on the dephosphorization and desulfurization was studied by the use of 2Na2CO3•Na2SO4 flux. The degree of dephosphorization and desulfurization considerably decreased and the evaporation of sodium increased with increasing temperature. As the flux was consumed for the oxidation of silicon, the degree was found to markedly decrease, whereas manganese in metal was found to gradually decrease. The reversion of phosphorus and sulfur was observed after the end of the flux addition.
The behavior of dephosphorization and desulfurization obtained with 2Na2CO3•Na2SO4 flux was compared with that with Na2CO3 flux or 2Na2CO3•Fe2O3 flux. The degree of dephospliorization for the three fluxes was almost the same, but remarkable evaporation of phosphorus was observed for 2Na2CO3•Fe2O3 flux according to the acceleration of CO formation by the reduction of iron oxide with carbon in metal. The phosphorus evaporation was also observed for 2Na2CO3•Fe2O4 flux, but its extent decreased with increasing content of P2O5 and SiO2 in the flux.
