A refractory to be used repeatedly or for a long period of time, such as a refractory for casting, especially a nozzle for casting and an SN plate, has improved tolerance. The refractory for casting contains Al.sub.4O.sub.4C in the range of 15 to 60% by mass, both inclusive, an Al component as a metal in the range of 1.2 to 10.0% by mass, both inclusive, and a balance including Al.sub.2O.sub.3, a free C, and other refractory component; a sum of Al.sub.4O.sub.4C, Al.sub.2O.sub.3, and the Al component as a metal is 85% or more by mass; and a content of Al.sub.4O.sub.4C (Al.sub.4O.sub.4C), a content of the Al component as a metal (Al), and a content of the free carbon (C). The contact of the free carbon satisfies the following Equation 1 and Equation 2:

1.0C/(Al.sub.4O.sub.4C0.038+Al0.33)(Equation 1)

and

1.0C/(Al.sub.4O.sub.4C0.13+Al0.67)(Equation 2).

A refractory to be used repeatedly or for a long period of time, such as a refractory for casting, especially a nozzle for casting and an SN plate, has improved tolerance. The refractory for casting contains Al.sub.4O.sub.4C in the range of 15 to 60% by mass, both inclusive, an Al component as a metal in the range of 1.2 to 10.0% by mass, both inclusive, and a balance including Al.sub.2O.sub.3, a free C, and other refractory component; a sum of Al.sub.4O.sub.4C, Al.sub.2O.sub.3, and the Al component as a metal is 85% or more by mass; and a content of Al.sub.4O.sub.4C (Al.sub.4O.sub.4C), a content of the Al component as a metal (Al), and a content of the free carbon (C). The contact of the free carbon satisfies the following Equation 1 and Equation 2:

1.0C/(Al.sub.4O.sub.4C0.038+Al0.33)(Equation 1)

and

1.0C/(Al.sub.4O.sub.4C0.13+Al0.67)(Equation 2).

A castable refractory composition may include from 5% to 95% by weight of alumina, aluminosilicate, or mixtures thereof; from 0.5% to 1.5% by weight alkaline earth metal oxide and/or hydroxide, and 0.1% to 5% by weight of silica having a surface area of at least about 10 m.sup.2/g. The refractory composition may include no more than 0.5% by weight of cementitious binder. The refractory composition may release less than 25 cm.sup.3 of hydrogen gas per kilogram of castable refractory composition upon addition of water. The refractory compositions may set on addition of water.

A ceramic susceptor particularly with excellent volumetric resistance at high temperatures and thermal conductivity at room temperature compared to a typical ceramic susceptor and a method for manufacturing the same are disclosed. The ceramic susceptor is characterized by comprising alumina (Al2O3); and aluminum nitride (AlN), and not comprising a secondary phase including an aluminum oxynitride phase (AlON phase).

A ceramic susceptor particularly with excellent volumetric resistance at high temperatures and thermal conductivity at room temperature compared to a typical ceramic susceptor and a method for manufacturing the same are disclosed. The ceramic susceptor is characterized by comprising alumina (Al2O3); and aluminum nitride (AlN), and not comprising a secondary phase including an aluminum oxynitride phase (AlON phase).

A ceramic susceptor particularly with excellent volumetric resistance at high temperatures and thermal conductivity at room temperature compared to a typical ceramic susceptor and a method for manufacturing the same are disclosed. The ceramic susceptor is characterized by comprising alumina (Al2O3); and aluminum nitride (AlN), and not comprising a secondary phase including an aluminum oxynitride phase (AlON phase).

A ceramic susceptor particularly with excellent volumetric resistance at high temperatures and thermal conductivity at room temperature compared to a typical ceramic susceptor and a method for manufacturing the same are disclosed. The ceramic susceptor is characterized by comprising alumina (Al2O3); and aluminum nitride (AlN), and not comprising a secondary phase including an aluminum oxynitride phase (AlON phase).

A porous refractory cast material contains a closed refractory aggregate fraction having a minimum particle size and a maximum particle size; the ratio of maximum particle size to minimum particle size is 10:1 or less. This closed refractory aggregate fraction comprises all of the porous refractory cast material having a particle diameter greater than 0.1 mm. The porous refractory cast material also contains a binder phase containing refractory selected from calcium aluminate cement, alumina phosphate, hydratable alumina, colloidal silica and combinations thereof. Also disclosed is a metallurgical vessel with an interior lining incorporating the porous refractory cast material.

A porous refractory cast material contains a closed refractory aggregate fraction having a minimum particle size and a maximum particle size; the ratio of maximum particle size to minimum particle size is 10:1 or less. This closed refractory aggregate fraction comprises all of the porous refractory cast material having a particle diameter greater than 0.1 mm. The porous refractory cast material also contains a binder phase containing refractory selected from calcium aluminate cement, alumina phosphate, hydratable alumina, colloidal silica and combinations thereof. Also disclosed is a metallurgical vessel with an interior lining incorporating the porous refractory cast material.