Application of phase equilibria and phase diagrams for lead and zinc blast furnace slags

Phase equilibria studies have been experimentally carried out in the ZnO-'FeO'-Al2O3-CaOSiO2-MgO system in equilibrium with metallic iron using high temperature equilibration, quenching and electron probe X-ray microanalysis techniques. Wustite (Fe,Zn)O and spinel (Fe, Zn)O center dot(Al, Fe)(2)O-3 are the major phases in the composition range investigated. The effects of Al2O3 and CaO/SiO2 ratio on the stabilities of the wustite and spinel phases and the liquidus temperatures have been systematically investigated in the composition range relevant to lead and zinc blast furnace slags. Partitioning of ZnO has been determined between liquid and solid phases. Applications of the results to the prediction of liquidus temperature and proportion of the solid phase are discussed for lead and zinc blast furnace slags