Structural Characterization of FeO-SiO2-V2O3 Slags Using Molecular Dynamics Simulations and FT-IR Spectroscopy

The structure of FeO-SiO2-V2O3 slags with compositions of (1-x)(1.5FeO center dot SiO2)center dot xV(2)O(3) (x=0-20% mole fraction) was investigated in the molten and quenched states by using molecular dynamics (MD) simulations and Fourier transform infrared (FT-IR) spectroscopy. An empirical potential for the multi-component system has been developed in this work for performing MD simulations. The local atomic structures and the micro-heterogeneity in the molten slag have been systematically investigated using MD simulations. The bond length of V-O varies from 1.92 to 1.96 angstrom and the averaged coordination number of V (CNV-O) increases from 4.50 to 4.96 with the addition of V2O3. The simulation results revealed that the average Si-O-Si bond angle and the degree of polymerization both decrease with increasing amount of V2O3, implying that V2O3 may behave as a network-modifying basic oxide in the FeO-SiO2-V2O3 system. This was further confirmed by the FT-IR spectrum analysis, which shows that the silicate network dissociates with the presence of V2O3.