Influence of alumina and magnesia on phase equilibria in the system Fe-CaO-FeOn-SiO2 at 1600 degrees C

The phase relations in the systems CaO-FeOn-SiO2-Al2O3 and CaO-FeOn-SiO2-Mg O at 1600 degreesC saturated with liquid iron are described. The phase cond itions in the quaternary system with aluminium oxide are so far rather unkn own. An addition of aluminium oxide makes the calciumsilicates and lime sat uration areas move towards the CaO corner thus enlarging the homogeneous li quidus space accordingly. Aluminium oxide can be considered as a flux In th is case. The fields of different solid solutions in the system CaO-FeOn-SiO 2-MgO were taken Into account. Some additional (2 to 4)-phase areas occur w ith increasing MgO content. This causes the precipitation of magnesiowustit e which dominates the system accordingly. The changed phase relations stron gly influence the direction of tie-lines and their length. Therewith, the c orrelation between liquid phase and solid phase, calculated via lever rule, is influenced, too.