How does chemical inertness help refractories in steelmaking and glassmaking?

Chemical inertness is a critical property for refractories because it allows furnace linings to withstand exposure to extremely corrosive molten materials and gases without participating in the chemical reactions occurring within the vessel.1

In steelmaking, basic refractories—such as those made from magnesia, dolomite, or chrome—are employed because they exhibit outstanding resistance to iron oxides and basic slags. By remaining chemically stable, these materials help maintain the integrity of the furnace lining, even though some degree of erosion and corrosion is inevitable during the process.23

In glassmaking, chemical inertness is equally vital to prevent the refractory from reacting with molten glass. Materials like zircon are specifically chosen for glass tanks due to their high resistance to the corrosive action of molten glass. Similarly, specialized alumina-chromite refractories are used because they are highly resistant to the corrosive effects of various fluxes and glasses. In these applications, manufacturers often increase the density of the ceramic material to minimize porosity, as a porous structure would otherwise increase susceptibility to chemical attack.145