Effect of CaF(2)on Phosphorus Refining from Molten Steel by Electric Arc Furnace Slag using Direct Reduced Iron (DRI) as a Raw Material

Abstract

The effect of CaF(2)addition on dephosphorization reaction between molten steel and electric arc furnace (EAF) slag using direct reduced iron (DRI) at 1823 K (1550 degrees C) was investigated. Basicity, the thermodynamic parameter affecting the removal capacity of phosphorus (i.e.,phosphate capacity), decreased using DRI due to an increased SiO(2)concentration in the slag. To minimize slag volume and maximize dephosphorization efficiency, the CaF(2)was added to the slag. As CaF(2)content increased (0 to 10 mass pct), dephosphorization efficiency also increased. Thermodynamic analysis in conjunction with slag structural studies using Raman spectroscopy were conducted to explain the complicated phenomena. The results exhibited that even 5 to 6 mass pct CaF(2)can improve the dephosphorization efficiency when DRI is used as raw material in an EAF process.