Phase equilibria study in the system “Fe2O3”-ZnO-Al2O3-(PbO+CaO+SiO2) in air

Phase equilibria studies have been undertaken first time in the system PbO-“FeO x ”-CaO-SiO 2 -ZnO-Al 2 O 3 . Pseudo-ternary section of the phase diagram “Fe 2 O 3 ”-ZnO-(PbO + CaO + SiO 2 ) with CaO/SiO 2 weight ratio of 0.93 and PbO/(CaO + SiO 2 ) weight ratio of 2.0 at fixed 4 wt% Al 2 O 3 has been constructed by equilibration and quenching technique. Zincite, spinel, melilite and Ca 2 SiO 4 are the major primary phases in the temperature and composition ranges investigated. It was found that, Al 2 O 3 stabilizes the spinel and melilite phases and extents their primary phase fields. The liquidus temperatures are increased in the spinel primary phase filed and decreased in the zincite primary phase field with increasing Al 2 O 3 . Significant difference of the liquidus temperatures is observed between the experimental data and FactSage calculations. Accurate compositions of the solid solutions have been determined in the present study together with the accurate temperature and liquid compositions. This study can provide direct support for industrial practice and optimization of the thermodynamic database.