Slag-metal interactions in the FeMn tapping process: Interfacial properties and wetting

FeMn-alloys are produced by transforming ore and carbon materials into FeMn and slag at high temperatures in a furnace. Entrainment of FeMn in slag during tapping reduces the yield. Entrainment and subsequent separation are strongly influenced by slag-metal interfacial properties. In the current work, interfacial properties, including the contact angle, in the FeMn-slag graphite system have been investigated using the sessile drop technique at temperatures above 1573 K. Two experimental configurations are proposed: (a) slag and metal placed beside each other on graphite; and (b) slag placed on top of the metal layer. The average interfacial tension between slag and metal over the temperature interval was found to be 1.08±0.10 N/m for slag-to-metal weight ratio 0.19, and 1.30±0.32 N/m for slag-to-metal weight ratio 0.28. In addition, wetting properties are considerably influenced by the variation of slag-metal weight ratio in the range from 0.25 to 1.50 and only marginally by temperature.