Influence of BaO on dephosphorization behavior of multiphase flux

Abstract

The dephosphorization behavior of multiphase steel slag in converter steelmaking process is very important for higher steel quality with ultra-low phosphorus content. In this paper, the multiphase steel slag with different BaO content reacted with hot metal at 1873 K temperature. The influence of the reaction on dephosphorization was investigated. The mineralogical phase was observed. The phosphorus partition between phosphorus enriched phase and liquid phase was discussed. The phosphorus partition ratio between steel slag and hot metal was obtained. The main mineralogical phases of steel slag were phosphorus enriched phase mCa2SiO4-Ba1-xCax(PO4)2 and RO (FeO/MgO) phase. The barium existed in phosphorus enriched phase and liquid phase, not in RO phase. The phosphorus content in phosphorus enriched phase increased from 1.12% to 1.36% with the addition of BaO. The phosphorus partition ratio between phosphorus enriched phase and liquid phase increased from 2.60 to 3.77, increased 45.00% by the addition of BaO. The phosphorus partition ratio between steel slag and hot metal increased from 55.35 to 97.50, increased 76.15% by the addition of BaO in steel slag.