Phase Diagram for the System CaO-Al2O3-ZrO2

Phase equilibria in the system CaO-Al2O3-ZrO2 were studied to optimize nozzle composition for tundishes that are used in continuous casters of steel, by identifying the composition that minimizes clogging. Mixtures of CaO, Al2O3, and ZrO2 with various compositions were equilibrated at 1873 and 1773 K and then quenched into water. X-ray diffraction analysis was used for phase identification, and electron probe microanalysis was employed to measure chemical compositions. On the basis of these and previous results, the eutectic and peritectic lines have been estimated. Based on the phase diagram, the optimal nozzle composition is CaO-saturated CaZrO3.