Nicolas David

Phase equilibria investigations and thermodynamic modeling of the PbO–Al2O3 system

Abstract The PbO–Al2O3 system has been extensively studied in literature. In the present study, experimental work was conducted in which equilibria between phases were investigated under air between 600°C and 800°C by X-ray diffraction. Three intermediate compounds reported in literature were confirmed, which are PbAl12O19 (1PbO:6Al2O3), PbAl2O4 (1:1) and Pb2Al2O5 (2:1). Results support a widely accepted version of the phase diagram in which these compounds exist. On the basis of the results obtained in this study and data considered from literature, a thermodynamic modeling according to the Calphad approach was performed, where all intermediate phases were considered as stoichiometric compounds and where the liquid phase was described by a two-sublattice ionic liquid model. Good agreement has been obtained from thermodynamic optimization in comparison with experimental results.