Viscosities in PbO − ZnO − “FexO” − SiO2–CaO system for lead and zinc smelting slags

Abstract

With the increase of Zn content in lead raw materials, it is essential to understand the viscous behavior of high lead-zinc smelting slags in improving the process efficiency and inhibiting the formation of foaming slag. In this article, the viscosities in lead and zinc smelting slag in the multicomponent system PbO-ZnO-“FexO”-SiO2-CaO were measured using the rotating cylinder method at a fixed ZnO/PbO mass ratio. The results indicated that the apparent viscosity increased with the increasing Fe/SiO2 mass ratio because of the formation of spinel (ZnxFe3-xO4+y) and zincite (ZnO) phase. The viscosity decreased with the increase of CaO/SiO2 mass ratio above 1573 K, and apparent viscosity increased significantly as the Ca3Fe15O25 and zincite phase emerged. The influences of Fe3O4, sulfur and CuO content of slag on apparent viscosities at lower temperatures were also due to the presence of crystals.