4 - Physical Characteristics of Mineral Wool Melts

Abstract

This chapter presents the practical mathematical expressions that are relevant for the production of mineral wool. Among the physical characteristics of silicate melts, the most relevant are density, viscosity, and surface tension. Vogel also considers the index of refraction, dispersion, Abbe number, molar refraction, heat dilatation, tension, heat conductivity, and electric conductivity. The first three physical characteristics are the most important for mineral wool production; therefore, the chapter focuses on the density, viscosity, and surface tension of mineral wool. The term, “Mineral wool,” refers collectively to rock wool and slag wool, though glass wool is sometimes included in this term as well. Because the rock and slag wool have different origins and differ chemically, they should be identified individually whenever possible. Like the other fibers, rock and slag wool are predominantly calcium and aluminum silicates. The chapter also presents general instructions for using the computing algorithm for calculation of density, viscosity, and surface tension of mineral wool melts.