Enrichment Mechanism of Phosphate in CaO-SiO2-FeO-Fe2O3-P2O5 Steelmaking Slags

The phosphate-enrichment behavior has experimentally been investigated in CaO-SiO2-FeO-Fe2O3-P2O5 steelmaking slags. The reaction ability of structural units in the slags has been represented the mass action concentration from the developed ion and molecule coexistence theory (IMCT)- model based on the IMCT. The defined enrichment possibility and enrichment degree of solid solutions containing P2O5 from the developed IMCT- model have been verified from the experimental results. The effects of binary basicity, the mass percentage ratio , and mass percentage of P2O5 in the initial slags on phosphate-enrichment behavior in the slags has also been discussed. The results show that the P2O5 component can easily be bonded by CaO to form tricalcium phosphate 3 CaO center dot P2O5, and the formed 3CaO center dot P2O5 can react with the produced dicalcium silicate 2CaO center dot SiO2 to generate solid-solution 2CaO center dot SiO2-3CaO center dot P2O5 under fixed cooling conditions. The maximum value of the defined enrichment degree of solid-solution 2CaO center dot SiO2-3CaO center dot P2O5 is obtained as 0.844 under conditions of binary basicity as 2.5 and the mass percentage ratio as 0.955 at fixed cooling conditions.