Experience with the use of mullite-corundum refractories in the roofs of electric-steel furnaces

The resistance of mullite-corundum roof articles, as for periclase chromite, is due to the absorption of melt products from the working region of the furnace and the action of one-sided, high-temperature heating, but in view of the considerable difference in the physicochemical properties the use of the first in the central zone of the roof, subjected to the most severe working conditions, is more desirable than the second.