Ramming mix for forming a mullite-corundum lining within a foundry furnace

In a method for forming a sintered refractory lining within a foundry furnace for defining a compartment for containing an iron melt, said method comprising positioning an expandable iron metal liner within said furnace to define the comaprtment, packing a dry, refractory, particulate ramming into a space about the metal liner, and filling compartment with an iron melt, whereupon the melt dissolves the iron liner and heats the ramming mix to sinter mix to form the refractory lining, the improvement wherein

• the ramming mix comprises a mixture of raw kyanite particles and alumina particles in an amount equal to at least 95 weight percent of the ramming mix, said kyanite particles being present in an amount between about 35 and 60 weight percent of the ramming mix and dissociating during sintering to form mullite and silica, said alumina particles being present in an amount sufficient to produce a weight proportion of alumina to silica in the mix of less than 4.6 and reacting during sintering with silica to form additional mullite, said ramming mix being characterized by dimensional expansion of at least 5 percent during sintering of a body while subjected to a 38 kPa load and effective to produce compressive forces in the packed ramming mix during sintering that strengthen the product lining, said sintered lining being substantially formed of mullite and corundum phases and resistant to attack by silica-base slag.