Molecular Dynamics Simulation on the Influence of Al2O3 on the Slag Structure at 1873 K

The influence of Al2O3 on the structure of the CaO-SiO2-Al2O3-10.00 wt.%MgOslag has been investigated by the molecular dynamics simulation at 1873 K. With the increase of the Al2O3 content, the average coordination numbers inCNSi-Si and CNAl-Si, decrease while those in CNSi-Al and CNAl-Al increase, meaning that more [SiO4] and [AlO4] tetrahedrons are surrounded by [AlO4] tetrahedron. The bridging oxygen, classified into Si-O-Si, Al-O-Aland Si-O-Al, is preferentially localized in Si-O-Al. The Al-O-Al/Al is much smaller than Al-O-Si/Al, showing that Al-O-Si bond is more stable than Al-O-Albond. For the Qn of Al and Si, the addition of the Al2O3 can promote the transformation of the simple polymers, such as Q0, Q1 and Q2, into complicated polymers, Q3 and Q4. The measure of the de-polymerization for the slag, NBO/T, drops rapidly from 1.68 down to 0.89, and the calculated viscosity increases from 0.19 up to 0.61 Pa·s.