Corrosion of zirconium-based refractories in glass-contact areas: Mechanisms and challenges

Zirconium-based refractories are essential materials in the glass industry due to their outstanding properties including high refractoriness, good thermal shock resistance, and high corrosion resistance with respect to contact with the molten glass, making them suitable for use in critical parts of glass melting furnaces, such as the bottom, side wall lining, and throat. Such refractories consist of zirconia (ZrO₂), zircon, or some combination with other oxides such as alumina (Al₂O₃) and silica (SiO₂), for example, as with Al₂O₃–ZrO₂–SiO₂ and high ZrO₂ refractories. Despite having good behavior when in contact with molten glass at high temperatures, these materials must be replaced periodically due to wear, primarily because of chemical corrosion. The complex corrosion process depends on different factors such as the temperature, glass composition, and the chemical composition and microstructure of the refractory material, among other factors. Much of the information is scattered across various sources, making it difficult to build a holistic understanding of the corrosion process of this specific kind of refractory so critical to the glass industry. The current paper intends to fill this gap by providing a comprehensive review of the corrosion of zirconium-based refractories used in glass-contact areas in glass making, enhancing our understanding of these refractories and identifying new areas for innovation.