Influence of the Al2O3‐contents in the ternary‐systems (FeO, MnO, CaO, MgO)‐ Al2O3‐SiO2 on the course of the mixture gaps in the ternary space

In accordance with the previous phase equilibria in the ternary systems (FeO, MnO, CaO, MgO)‐ Al 2 O 3 ‐SiO 2 even small Al 2 O 3 ‐contents should be sufficient to close the wide mixture gaps in the binary edge systems of FeO‐SiO 2 , MnO‐SiO 2 , CaO‐SiO 2 and MgO‐SiO 2 , which are stable in the temperature range from 1700 to 2100‐2200°C. Thermodynamically this acceptance is not impossible but rather improb‐able. Based on phase‐theoretical considerations and the previous results of literature about the course of an unstable mixture gap in the system SiO 2 ‐Al 2 O 3 two thermodynamically founded versions were developed as possible, resulting phase equilibria in the SiO 2 ‐rich, but experimentally not exactly examined part of the mentioned ternary‐systems, and were added to the experimentally secured sections of these systems unproblematically.