Corrosion resistance evaluation of highly dispersed MgO-MgAl2O4-ZrO2 composite and analysis of its corrosion mechanism: A chromium-free refractory for RH refining kilns

摘要

The corrosion resistance behavior of a highly dispersed MgO-MgAl2O4-ZrO2 composite refractory material is examined by testing with high-basicity and low-basicity RH (Ruhrstahl-Hereaeus) slags. The composite material exhibits greater resistance to the RH slags than the traditional MgO-Cr2O3 composite, MgO-ZrO2 composite, and MgO-MgAl2O4-ZrO2 composite. On the basis of the microstructural analysis and mechanisms calculations, the corrosion resistance behavior of the MgO-MgAl2O4-ZrO2 composite is attributable to its highly dispersed structure, which helps protect the high activity of ZrO2. When in contact with the slag, ZrO2 reacts with CaO to form the stable phase CaZrO3, which protects MgAl2O4 against corrosion, thereby enhancing the corrosion resistance of the composite.