Microstructural analysis by molecular dynamics simulation of aluminate ternary slag with alkaline oxide

The influence mechanism of Na2O, K2O, MgO, and BaO on the microstructural characteristics of aluminate-based ternary melts was investigated using molecular dynamics simulation to guide performance adjustments. When the MxO mass fraction was 4 wt%, compared with alkaline earth metal oxides, adding alkaline metal oxides can stabilize the Al-O bond and Al-O coordination better. The sequence of Mx+ close to the [AlO4]5- tetrahedron was Mg2+<Ca2+<Ba2+<Na+<K+, and M+ primarily compensates for the [AlO4]5- tetrahedron charge, while more AlV was formed in two-valence alkaline aluminate to balance the excess negative charge. As the MxO mass concentration increased, in the K2O-Al2O3-CaO, Na2O-Al2O3-CaO, and BaO-Al2O3-CaO systems, the Mx+ replaced Ca2+ in the [AlO4]5- tetrahedron and approached Ot to balance the excess negative charge, while in the MgOAl2O3-CaO system, Mg2+ replaced Ca2+ in Onb and approached Ot to form non-bridging Al-O-Mg. Combined with the synergistic effect of Mx+, AlV, and Ot, the melt structure complexity followed the trend of MgO-Al2O3CaO<Na2O-Al2O3-CaO<K2O-Al2O3-CaO<BaO-Al2O3-CaO with a certain mass fraction of MxO.