Structural Investigation of Phosphorus in CaO-SiO2-P2O5 Ternary Glass

The system of CaO-SiO2-P2O5 ternary glass is not only among the major constituents of steelmaking slags in iron and steel industry, but also play a significant role in other industrial process, such as chemical engineering and glass industry. In the present study, the structure of CaO-SiO2-P2O5 ternary glass with varying P2O5 content from 0 to 15 wt pct at a fixed CaO/SiO2 = 1.4 was investigated using molecular dynamics (MD) simulation combined with X-ray photoelectron spectroscopy and Raman spectra techniques. The results indicated that P5+ ions have a higher affinity to Ca2+ ions which are then stripped away from the silicate network with the addition of P2O5, resulting in the formation of Ca-O-P and Si-O-Si linkages. In addition, almost all P5+ ions displayed as (, n is the number of bridging oxygen in one [PO4]-tetrahedra units) and a small fraction of P5+ ions behave as (P-O-P) and P-O-Si. The enhanced degree of polymerization can be detected from the increase of and (mole fraction of or ). Furthermore, the ratio of Raman scattering coefficients for and were determined by combining MD simulated result with Raman spectra, which were considered to be suitable to the present study.