Influence of the Glass Phase of Fusion-Cast Refractories on Their Operational and Technological Properties

This work presents the properties of the glass phase of fusion-cast refractories with 28 – 94% ZrO₂. The effect of glass phase composition on the main performance properties of refractories, namely, corrosion resistance and tendency to release defects, is discussed. It is revealed that a decrease in the amount of glass phase in fusion-cast baddeleyite-corundum refractories with a simultaneous increase in the amount of ZrO₂ results in an increase in corrosion resistance and complication of the annealing conditions of the products. The glass phase properties that determine the tendency of refractories to release defects depend mainly on the SiO₂ to Na₂O ratio, the purity of raw materials, and the method of charge melting. Oxidative melting with treatment of the melt with an oxygen–gas mixture is a prerequisite for the formation of a refractory glass phase in refractories and manufacturing products with a low tendency to the formation of defects.