Insight into the structure and transport properties of CaO-SiO2-P2O5 system during the phosphorus enrichment process: A molecular dynamics simulation

Since alpha-2CaO center dot SiO2 has a high solubility for dopant P, it can form the solid solution n2CaO center dot SiO2-3CaO center dot P2O5 (nC2S-C3P) during the dephosphorization process of steelmaking. The present work uses the molecular dynamics method to discuss the molecular structure and transport properties of the CaO-SiO2-P2O5 system during the phosphorus enrichment process. During the phosphorus enrichment process, [SiO4]4- and [PO4]3- both maintain good fourfold coordination states. The proportions of free oxygen and bridging oxygen gradually decrease from 8.06 % and 8.86 % at C2S to 2.44 % and 2.47 % at C3P, respectively, while the non-bridging oxygen increases from 83.08 % to 95.08 %. The viscosities of the CSP system decrease with increasing the enrichment degree of phosphorus. The thermal stability of the CSP system decreases due to the decrease in enthalpy value. The decrease in macroscopic viscosity of the CSP system during the phosphorus enrichment process is reasonably consistent with the decrease in microstructural polymerization degree.