Refractory corrosion by slag under an applied voltage

The effect of an applied voltage on the dissolution rate of MgO refractory in two steelmaking type slags has been investigated. It was found that the MgO corrosion in a CaO-SiO2-Al2O3 based slag proved insensitive to an applied voltage over the voltage range –0.5 to 0.3V. The corrosion rate of the dense MgO in a CaO-SiO2-Fe2O3-FeO-MgO slag showed a maximum corrosion rate at –0.45V. This effect has been explained by considering the consequences of an applied voltage on the rate of Marangoni flow at the slag-refractory-gas interface and in turn, the flow effect on the rate of the mass transfer controlled MgO dissolution reaction.