Abstract: A configuration in which particles of pitch 2 having a softening point in the range of 70 to 200° C. and a diameter equal to or smaller than 30 ?m are held on the surfaces of particles of a refractory raw material 3 having a diameter equal to or smaller than 50 ?m is employed. This pitch-containing refractory raw material 1 can be used with the pitch being in a fine-particle form without any aggregation even after the long-term storage. Using it as a part of a raw material formulation allows the fine particles of pitch to be uniformly dispersed during the mixing or kneading process. The resulting carbon-containing refractory has an excellent corrosion resistance. It also provides suppressed increase in the Young's modulus while maintaining the level of strength, thereby being excellent in thermal spalling resistance even with the carbon content ratio being low.

Abstract: A configuration in which particles of pitch 2 having a softening point in the range of 70 to 200° C. and a diameter equal to or smaller than 30 ?m are held on the surfaces of particles of a refractory raw material 3 having a diameter equal to or smaller than 50 ?m is employed. This pitch-containing refractory raw material 1 can be used with the pitch being in a fine-particle form without any aggregation even after the long-term storage. Using it as a part of a raw material formulation allows the fine particles of pitch to be uniformly dispersed during the mixing or kneading process. The resulting carbon-containing refractory has an excellent corrosion resistance. It also provides suppressed increase in the Young's modulus while maintaining the level of strength, thereby being excellent in thermal spalling resistance even with the carbon content ratio being low.

Abstract: A casting apparatus for low-melting metals has a coating layer of two-layered structure which hardly reacts with low-melting metals, adheres firmly to the substrate, and protects the substrate from thermal and mechanical shocks for a long period of time. The layer in contact with the substrate contains glass powder having a melting point below 1000.degree. C. and at least one binder selected from silicates and phosphates. The layer in contact with molten metal contains 5-80 wt. % of at least one fluorine compound (as a corrosion resistant material) having a melting point of above 700.degree. C. Owing to the multiple layers, each having a specialized function, the casting apparatus has improved durability over a long period of time.