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

Abstract

Phase equilibria studies have been experimentally carried out in the ZnO–‘FeO’–Al₂O₃–CaO–SiO₂–MgO system in equilibrium with metallic iron using high temperature equilibration, quenching and electron probe X-ray microanalysis techniques. Wüstite (Fe, Zn)O and spinel (Fe, Zn)O⋅(Al, Fe)₂O₃ are the major phases in the composition range investigated. The effects of Al₂O₃ and CaO/SiO₂ ratio on the stabilities of the wüstite 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.

Keywords

Liquidus temperature Phase equilibria EPMA Slag

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