The use of Missouri Super Duty Refractories in steel plant service is not new, although their use in blast furnace service has been limited chiefly to stove installations. They have, however, been used in a sufficient number of places where severe operating conditions exist, so that they are a definitely known quantity and they have consistently shown much longer service under conditions of high temperatures and contact with slag and molten iron. One outstanding comparison of the service which these brick give over ordinary first quality brick is the bottom of a malleable iron furnace. Not first quality refractory has successfully been used for this service, and until A.P. Green Fire Brick Company pioneered this service for their super duty brick ti was necessary for the malleable operator to use a sand bottom and rebuild the bottom at the end of each week. No first quality refractories had lasted over thirty to thirty-five heats under these conditions, but super duty brick consistently give from one hundred to one hundred and fifty heats, making it much more economical to use these brick for this service. It must be remembered that in malleable bottoms the brick are subjected to the direct erosion of molten metal and slag at 3000°F which is extremely severe service --Introduction, page 1
