Equilibria of Manganese and Sulfur between Liquid Iron and CaO-SiO_2-Fe_tO-MgO-MnO Slags Saturated with 2CaO·SiO_2 and MgO

摘要

The equilibria of manganese and sulfur between liquid iron and CaO-SiO_2-Fe_tO-MgO slags saturated with dicalcium silicate and MgO were studied in the temperature range of 1823 to 1923 K. The solubility of MgO decreases with increasing Fe_tO content. The values of (%MnO)/[%Mn] increase with increasing Fe_tO content and its relation was formulated by an empirical equation. The activity of Fe_tO for the present slag system almost stays unchanged with increasing Fe_tO content investigated. The oxygen content of metal in equilibrium with (39.9～49.9mass%)CaO-(11.9～15.2mass%)SiO_2-(25.2～35.7mass%)Fe_tO-(6.1～7.0mass%) MgO slags saturated with 2CaO · SiO_2 and MgO is expressed by the following equation. log[mass%O] = -5690/T + 0.011 The logarithm of the sulfide capacity for the present slags increases with increasing the theoretical optical basicity and its correlation was formulated. Using the relations obtained in this work and mass balance, the charging amount of Mn ore(MnO) for a final manganese content when adding MnO to BOF was predicted and the desulfurized content affected by the addition of Mn ore was also estimated.