Phosphorus Capacity of CaO-SiO2-Al2O3-MgO-FexO Slag

The CaO-SiO2-Al2O3-MgO-FexO slag occurs in the production process of Corex ironmaking technology. Most of its metallurgical properties, especially the phosphorus property, are different from the slag produced from blast furnace or converter. In order to explore the dephosphorization ability of CaO-SiO2-Al2O3-MgO-FexO slag, its phosphorus capacity was measured at 1673 K by gas-slag-metal equilibrium technique. An iron crucible was used as the reaction vessel, Ag alloy with 0.2% P was used as the metal phase which equilibrated with CaO-SiO2-Al2O3-MgO-FexO slag, and a constant flow of CO-CO2-N2 gas was used to provide oxygen partial pressure in the experiment. The effects of MgO, FexO and basicity on slag phosphorus capacity were investigated by single factor test. The results show that the phosphorus capacity rises firstly and then decreases with increasing MgO content under the condition of basicity 1. 3, FexO content of 2% and Al2O3 content of 12%. The phosphorus value reaches maximum as the MgO content is 8%. When the basicity of slag is 1. 1, MgO content is 10%, and Al2O3 is 12%, the phosphorus capacity increases with the increase of FexO content. The phosphorus capacity rises linearly when the basicity is increased from 1. 1 to 1. 5.