The effect of CaF2 and Na2O on the sulfide capacity of the CaO-SiO2-CaF2-MgOsatd (-Na2O) slags for hot metal desulfuhzation was investigated at 1 623 and 1 723 K by taking the role of MgO as an important refractory component into account. The liquidus line of the MgO-saturated system was similar to the CaO-SiO 2-CaF2 ternary slag system. The silica content for the 2CaO·SiO2-saturation was slightly decreased with MgO saturation. Although the sulfide capacity at MgO-saturation is lower than that of the CaOsatd -SiO2-CaF2 slag system, it is greater than the ternary slag system saturated with 2CaO· SiO2 phase. This suggests that MgO can increase the activity of free O2- ions under conditions of relatively low CaO activity. Near the composition of 3CaO SiO2-saturation, MgO decreased the sulfide capacity of the slag because MgO is less basic than CaO in highly basic compositions. In addition, the addition of 5 mass% Na2O significantly increases the sulfide capacity of the MgO-saturated slag especially in the composition of low 'CaO+CaF2' This suggests that the input amounts of 'CaO+CaF 2' can be reduced from 95 to 75 mass% for maintaining the sulfide capacity of 0.01 at 1 623 K, which is important considering the reduction of CaO and CaF2 consumption in hot metal desulfurization process with MgO saturation.
All Science Journal Classification (ASJC) codes
- Mechanics of Materials
- Mechanical Engineering
- Metals and Alloys
- Materials Chemistry