Insight into the structure and transport properties of CaO-SiO2-P2O5 system during the phosphorus enrichment process: A molecular dynamics simulation
Han Sun, Jian Yang, Runhao Zhang, Longyun Xu
Abstract
Since α-2CaO·SiO 2 has a high solubility for dopant P, it can form the solid solution n 2CaO·SiO 2 –3CaO·P 2 O 5 ( n C 2 S-C 3 P) 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-SiO 2 -P 2 O 5 system during the phosphorus enrichment process. During the phosphorus enrichment process, [SiO 4 ] 4− and [PO 4 ] 3− both maintain good fourfold coordination states. The proportions of free oxygen and bridging oxygen gradually decrease from 8.06 % and 8.86 % at C 2 S to 2.44 % and 2.47 % at C 3 P, 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.