LAUSR

Phase equilibria of the PbO-SiO2 system have been established for a wide range of compositions: (a) liquid in equilibrium with silica polymorphs (quartz, tridymite and cristobalite) between 740°C and 1580°C, at 60-90 mol.% SiO2; (b) with lead silicates (PbSiO3, Pb2SiO4 and Pb11Si3O17) and lead oxide (PbO) between 700°C and 810°C. A high-temperature equilibration/quenching/electron probe X-ray microanalysis (EPMA) technique has been used to accurately determine the compositions of the phases in equilibrium in the system. Significantly, no liquid immiscibility has been found in the high-silica range, and the liquidus in this high-silica region has been accurately measured. The phase equilibria information in the PbO-SiO2 system is of practical importance for the improvement of the existing thermodynamic database of lead-containing slag systems (Pb-Zn-Fe-Cu-Si-Ca-Al-Mg-O). This article is protected by copyright. All rights reserved.