Experimental examination of slag/refractory interface

Abstract

Ladle glazes are a thin coating of slag formed when the top slag comes in contact with the refractory during draining of the ladle. It is believed that ladle glazes are a major source of inclusions in the next cast of steel held in that ladle. Pilot plant trials, simulation tests, and thermophysical property measurements have been carried out on the glazes to: (i) obtain more information about ladle glazes and the factors affecting their formation and subsequent removal from the refractory; (ii) provide direct evidence that glazes are a major source of inclusions; (iii) study the factors affecting the formation, adhesion, and thickness of the glaze; (iv) study the formation of the slag penetrated layer and the factors affecting penetration. Doping trials have shown that ladle glazes are a major source of inclusions. The calculated thickness of the adhered slag layer was appreciably lower than measured experimental values. Calculated horizontal slag infiltration depths were in reasonable agreement with values measured on plant, but measured vertical infiltration depths were much lower than calculated values. It has been shown that slag penetration can be significantly reduced by the application of an electrical potential.