Activity of AlO1.5 for the CaO-AlO1.5-CeO1.5 system at 1 773 K

The isothermal phase relations for the CaO-AlO1.5-CeO1.5 system have been i nvestigated at 1773 K by a chemical equilibration technique. Activity of Al O1.5 in this system was also measured by equilibrating molten Cu and the Ca O-AlO1.5-CeO1.5 flux under a controlled oxygen partial pressure. The activi ty coefficient of Al at infinite dilution in molten Cu was determined at 17 73 K. Iso-activity curves of AlO1.5 for the CaO-AlO1.5-CeO1.5 system are dr awn from the experimental results. The addition of CeO1.5 to the CaO-AlO1.5 system was found to decrease the activity coefficient of AlO1.5 in the mel ts. The effect of Ce addition to Al-killed steel was also discussed using t he present results.