LAUSR

To explore the influence of Al2O3/TiO2/Na2O on the mineralogical structure and phosphorus enrichment of converter slag, phosphorus enrichment and distribution in the CaO–SiO2–Fe2O3–MgO–Al2O3/TiO2/Na2O slag system were experimentally examined. The results show that phosphorus mainly exists in an n2CaO·SiO2–3CaO·P2O5 (nC2S–C3P) solid solution. Al2O3/TiO2/Na2O is beneficial for phosphorus enrichment in the CaO–SiO2–Fe2O3–MgO slag system to various degrees. This allows screening and separation of the enriched phase in the slag. When Al2O3 content was increased from 0 to 15%, the P2O5 content in the P-rich phase increased from 13.88 to 21.32%, and the area of the P-rich phase decreased from 57.50 to 37.87%. When the TiO2 content was increased from 0 to 10%, the content of P2O5 in the P-rich phase increased from 13.88 to 22.90%, and the area of the P-rich phase decreased from 57.50 to 39.20%. When the contents of Al2O3 and TiO2 were increased, the previously formed nC2S–C3P solid solution transformed into n′C2S–C3P (n < n′) with higher phosphorus content. Na2O had no significant effect on phosphorus enrichment, but exerted significant influence on the area of the P-rich phase. When the Na2O content was increased from 0 to 8%, the previously formed nC2S–C3P solid solution gradually became Na2Ca4(PO4)2SiO4, and the area of the P-rich phase increased from 57.50 to 68.50%. With increasing the content of ATN (a mixture with a mass ratio of Al2O3/TiO2/Na2O = 15:4:3) from 0 to 30%, the content of P2O5 increased from 13.88 to 42.10% and the area of the P-rich phase decreased from 54.92 to 18.40%.