Slag conditioning effects on MgO–C refractory corrosion performance

Slag conditioning practice provides important benefits to the steelmaking processes including ladle refractory life improvement, lower flux cost/additions, better control of metal recovery, among others. Furthermore, with the advent of thermodynamic and mass balance calculations it is possible to predict the slag saturation and define the most suitable conditioner (oxide components) that should be added during the operational process. Thus, the aim of this work was to analyze the interaction of industrial slags and a MgO–C refractory composition by thermodynamic simulations (FactSage™). Based on the attained results, a conditioned slag was designed and corrosion tests in the laboratory were carried out (cup-tests and induction furnace), for two MgO–C materials containing distinct magnesia sources. According to the calculated slag penetration area and refractory corrosion rate, a remarkable enhancement of the MgO–C bricks wear resistance was observed when such materials were placed in contact with the conditioned molten slag. Therefore, proper slag engineering can be a suitable replacement for purchased synthetic slags and the conditioning practices can directly improve refractory life, with more competitive costs for both, refractory producers and end-users.