Experimental and Theoretical Contribution to the Phase Equilibria in the Ternary CaO-Al 2 O 3 -B 2 O 3 System

The phase equilibria in the lime rich part of the CaO-Al 2 O 3 -B 2 O 3 ternary system were investigated by thermodynamic modeling and key experiments. Three ternary compounds, CaAl 2 B 2 O 7 (CAB), Ca 2 Al 2 B 2 O 8 (C 2 AB) and Ca 2 Al 2 B 6 O 14 (C 2 AB 3 ), are reported in the literature and their thermodynamic properties were calculated using Density Functional Theory and lattice dynamics theory. Partial isothermal sections of the lime rich part of the CaO-Al 2 O 3 -B 2 O 3 ternary system were investigated at 950 and 1020 °C using solid state reactions and x-ray diffraction on 14 selected samples. The observed results confirm the available experimental data from the literature. Based on thermal analysis using differential scanning calorimetry, the Ca 3 Al 2 O 6 -CaB 2 O 4 and CaAl 2 O 4 -CaB 2 O 4 T-x sections as well as a tentative partial liquid surface of the lime rich part were constructed.