Application of Bayer Red Mud-Based Flux in the Steelmaking Process

摘要

Bayer red mud is characterized by its highly oxidizing nature (high Fe2O3 content) and high alkalinity (high Na2O content). It can work as an ideal flux and dephosphorizer in the steelmaking process. In this study, laboratory experiments on the use of Bayer red mud-based flux in hot metal dephosphorization and simulated steelmaking processes have been carried out. In hot metal dephosphorization, good slag fluidity and a much better separation between the slag and the melt phases are obtained while using Bayer red mud. This result is attributed to the fact that Al2O3 and Na2O present in Bayer red mud act as a flux and serve to decrease the melting point of the CaO-FeO-SiO2-based slag. For a mass ratio of Bayer red mud:CaO between 1:1 and 2:1, high hot metal dephosphorization ratios (more than 80%) and low final [P] (lower than 0.018%) are obtained. The experimental results obtained while using Bayer red mud-based flux in simulated steelmaking processes show that good slag fluidity is observed during the entire process. The dephosphorization ratio can be more than 85%, and the final [P] can be lowered to less than 0.005%. No rephosphorization phenomenon is observed in the whole experiment.