Corrosion Resistance Mechanism of MgO-ZrO2 Brick in RH Degasser Slag
Slag corrosion resistance behavior of MgO-ZrO2 refractory was investigated in this work. The results indicated that in the non-oriented electric steel slag system with a high ratio of calcia to silica, the slag resistance behavior of MgO-ZrO2 composite could be described as follows: the ZrO2 reacts with CaO forming the calcium zirconate compound which is densification encapsulating periclase lay. However, in the oriented electric steel slag system with a high concentration of silica and the low ratio value of calcia to silica, the slag corrosion resistance behavior of MgO-ZrO2 composite is different. The ZrO2 would react with CaO forming the calcium zirconate and simultaneously, one more product C2S as well. C2S has double response of strength and could increase corrosion resistance performance by blinding pore and thickening slag viscosity. Therefore, it is expected to be the major reason for the enhanced corrosion resistance behavior observed for MgO-ZrO2 refractory.