Surface interactions between non-ferrous metallurgical slags and various refractory materials

grantor: University of TorontoSurface and interfacial phenomena, such as contact angles and interfacial reactions play an important role in determining the longevity of refractory bricks. To extend refractory life, a large contact angle and a slag insoluble interfacial reaction product are desired. To obtain a better understanding of the complex corrosion mechanisms occurring at the interface, the surface and interfacial properties between fayalite and calcium ferrite slags and various high melting temperature materials were investigated at 1200$\sp\circ$C under a controlled oxygen potential environment. The materials employed can be characterized into four groups; first, magnesia, which is the most important material relating to refractories used by non-ferrous producers. Secondly, magnesia-based spinels and solid solutions of these spinels which represent another important component of commercial bricks. Thirdly, pure oxides which are not present in the bricks as such, but by acquiring fundamental data, insight can be gained into the corrosion mechanisms. Finally, novel materials are evaluated for their future potential as refractory materials. The fayalite-type slags were wetting to all of the solid substrates with the exceptions of graphite and boron nitride (BN), which reacted vigorously with the slag. The interfacial reaction products between the slags and the refractory materials were determined. All materials formed a reaction product when in contact with the slags with the exception of MoS$\sb2.$ The reaction products consistently involved iron from the slag phase indicating that a large chemical potential exists between the iron in the slag and the solid substrates. Magnesia and alumina were found to dissolve into the slags in relatively large quantities while chromium oxide did not. Surface tension of the fayalite-type slags were also determined.Ph.D