Surface Tension during Molten Metal Granulation

The surface tensions of a number of common commercial ferroalloys have been measured during their granulation in water. These measured values are significantly lower than would be expected from a normal metal-gas interface and are more typical of the interfacial tensions of slag-gas interfaces. This would seem to indicate that the slag-metal interface on the surface of a granule produces no significant interfacial tension. An electron microscope study on sections through the surface layers of granules showed that, in some cases, although not in all, emulsification had occurred at the slag-metal interface.