Effect of multiphase flux with BaO addition on phosphorus partition

Abstract

It is important to clarify the effect of BaO in phosphorus partition of multiphase flux. In current work, the slag CaO-SiO2-FetO-P2O5 with different contents of BaO was cooled from 1873 K to 1673 K to investigate the effect of BaO on phosphorus partition of solid solution. The phosphorous partition between the solid solution phase and liquid phase was obtained. In order to further inspect the effect of BaO on phosphorus partition, the experiment of reaction between 2CaO · SiO2 (C2S)-FetO/Fe2O3-BaO slag and hot metal was carried out. Furthermore, the CaO-FetO slag was also studied to compare the dephosphorization effect to C2S-FetO/Fe2O3-BaO slag. The phosphorus partition ratios Lp between the slag and hot metal were obtained. The result showed that when the slag CaO-SiO2-FetO-P2O5-BaO with various BaO content was cooled down from 1873 K to 1673 K, the solid solution was precipitated, and the enrichment of phosphorus in solid solution phase was improved with the addition of BaO. The phosphorus element content in solid solution increased from 4.16% to 5.27% with the increasing of BaO content in slag from 0 to 15% at the interval of 5%. Based on the experiment of reaction between slag and hot metal, the phosphorus content in hot metal showed that the barium ion was more beneficial to enrichment of phosphorus and the function of BaO was promoted by the addition of Fe2O3. The phosphorus partition ratio Lp between the slag C2S-FetO-BaO and hot metal was 295.38, which was higher than 208.24 that without BaO. The phosphorus partition ratio Lp between the slag CaO-FetO and hot metal was 217.50. The phosphorus partition ratio Lp between the slag C2S-Fe2O3-BaO and hot metal was 418.75, higher than that of the slag C2S-FetO-BaO.