Basic oxygen furnace and refractories therefor having improved thermal

Abstract

A steel refining furnace and refractories therefor having improved thermal conductivity may be achieved by the use of refractory bricks containing 31/2 to 51/2% residual carbon and having metal plates and the like associated therewith externally and, in many instances, internally. The cold face of the brick should be protected by a metal shell. Such a brick will have high thermal conductivity to achieve a cooler hot face of the basic oxygen furnace lining whereby to improve and decrease the rate of slag erosion in the furnace and to improve the thermal shock resistance of the refractory lining. An improved furnace is realized by utilizing the novel brick in specific areas thereof such as under the lip ring and in the trunion areas. Preferably the brick itself will be a pitch bonded magnesia refractory having an internal and external metal casing (chemically bonded by combining the refractory grains with prescribed amounts of coal tar pitch, carbon and/or grahite, tempering the mixture, pressing it into bricks while adding the metal elements, and drying them), or an external metal casing of burned pitch impregnated refractory (direct bonded by molding and firing, at high temperatures on the order of 3000.degree. F., 1650.degree. C., whereafter the bricks are impregnated with carbon in some form and the metal elements are added). The metal elements must be prevented from oxidation, thus the requirement for the presence of residual carbon in the brick and the use of a metal shell to shield the cold face thereof from oxygen penetration.