Physicochemical properties of molten CaF₂ -based slags

Abstract

Slags based on CaF₂ are used extensively in electroslag remelting (ESR) and in some welding processes. The physical properties of the slag can affect its efficiency in these applications. The influence of the various physical properties of the slag upon the performance of ESR units is discussed. The effects of chemical reactions which cause changes in the composition of the slag, together with the evolution of volatile fluorides and oxides, are reviewed and discussed. Extant data for the following physicochemical properties are collated and evaluated; phase diagrams, activities, electrical conductivity, viscosity, density, and surface tension. Where possible, recommended values for these properties are given on the basis of this assessment.