Simultaneous Dephosphorization and Desulfurization of Carbon-saturated Iron by Sodium Carbonate-Sodium Sulfate Flux

抄録

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.