1979 Volume 65 Issue 13 Pages 1838-1847
Reactions of Na2CO3or Na2SO4with iron, carbon and phosphorus, respectively were studied in the temperature range between 1200 and 1400°C by the use of iron, graphite and magnesia crucibles. The reaction between Na2SO4and iron was much more active than that between Na2CO3and iron, but the reaction between Na2CO3and carbon was considerably violent compared with that between Na2SO4and carbon. Reactions of Na2CO3and Na2SO4. with phosphorus (Fe-18%P alloy) were determined as follows;
Na2CO3 (1) + 4/5 P =Na2O (1) +2/5 P2O5 (1) + C
Na2SO4 (1) + 4/5 P = 2/3 Na2O (1) + 2/5 P2O5 (1) + 1/3 Na2S (1) + 2/3 SO2
The dephosphorization and the desulfurization of carbon-saturated iron (0.2 %P, 0.05 %S) were also investigated at 1 250°C by the Na2CO3-Na2SO4 flux. From the chemical composition in flux analyzed before and after experiments, the degree of the dephosphorization and the desulfurization and the evaporation loss of sodium and sulfur were obtained as a function of the flux composition. Thus the degree of the dephosphorization was almost independent of the flux composition. With increasing the Na2SO4concentration, the degree of the desulfurization, the evaporation loss of sodium and iron yield decreased, but its loss of sulfur decreased with increase in the Nam2CO3concentration. The evaporation loss of sodium decreased with increasing the P2O5 concentration in slag.