Abstract: A hearth for use in a furnace, which comprises an upper layer of magnesia containing chromic oxide, a lower layer containing graphite and an organic bonding agent, and an intermediate layer of a mixture of the materials forming the upper and lower layers. The hearth is particularly useful in DC arc funaces, in which steel rods embedded in the bottom act as the anode. The hearth has improved service durability.

Abstract: Refractory compositions which can be gun-applied, or refractory, unfired shapes containing sintered magnesite and/or sintered dolomite as the principal refractory component, 0.5 to 5% by weight of bentonite, 1 to 5% by weight of aluminum sulfate and 0.5 to 5% by weight of an alkaline earth compound, characterized by the fact that they contain magnesium hydroxide and/or caustic-calcined MgO as the alkaline earth compound. The compositions and shapes of the invention have the advantage that they do not exhibit binder migration, and no damping-reduction cracks or chipping occurs therein.

Abstract: An electrode for an electric arc furnace includes a cooled metal sheath covered with a refractory protective jacket. A plurality of refractory anchors are fixed to the exterior of the sheath, and the anchors are spaced from each other. The protective jacket includes an undercoat on the exterior of the sheath and a protective layer over the undercoat and extending between the anchors. The protective layer is formed of a refractory material such that, at the operating temperature of the electrode, the protective layer has an inner zone which is thermoplastic and an outer zone which is rigid or which is a high-viscosity melting phase.