Using red mud-based flux in steelmaking for high phosphorus hot metal

Abstract

To smelt high phosphorus hot metal effectively, a new flux named Red Mud (RM) was applied in steelmaking to form CaO–FeO–SiO2–Al2O3–Na2O slag. Good slag fluidity and dephosphorization effects can be achieved when using RM-based flux in simulated steelmaking for high phosphorus hot metal. The dephosphorization rates of the RM-based flux were all greater than 82%. Especially, when RM:CaO = 1:1.2, high dephosphorization rate (~95%) and low final [P] (= 0.02%) was achieved in the situation of high [C] = 1.36%. This is of great importance for the production of clean steel. The P2O5 content in the P-rich phase in RM-based slag can reach 29.1 wt%, far higher than the 9.1 wt% in lime-based slag.