Abstract: Disclosed is a taphole plugging composition for metal melting apparatus, the composition comprising (a) a refractory aggregate having a maximum particle size of 5 mm or less, (b) graphite and silicon nitride each having a maximum particle size of 0.2 mm or less, (c) a refractory clay, (d) a compatibilized binder mixture comprising a phenolic resin, a ketone compound and a pitch, and (e) an organic fine fiber.

Abstract: The present invention is directed to molten metal vessels and molten metal holding furnaces containing a molten metal vessel. The molten metal vessel has a double-layer structure that includes an inner layer vessel in the form of a nonoxide-containing fired casting, and an outer vessel layer made from a calcium silicate refractory. The inner layer of nonoxide-containing fired casting can be obtained by firing in a reduced atmosphere a box-shaped vessel having an open upper side and prepared by casting a monolithic refractory comprising primarily of a silicon carbide material or silicon nitride material. The outer vessel layer of calcium silicate refractory can be obtained by casting calcium silicate monolithic refractory around the inner vessel layer, and thereafter curing, solidifying and drying the resulting casting.

Abstract: A continuous melting apparatus for a low melting point metal is disclosed. The apparatus includes a melting furnace main body (5) forming a combustion chamber (6) surrounded by a refractory lining, a crucible (1) formed with a tapping orifice (2) at an appropriate position of a body and housed at the center portion of said combustion chamber, a burner (8) provided on a side wall portion of said melting furnace main body (5) for heating said crucible (1) in said combustion chamber (6) and a receptacle (6, 13) for receiving a melt flowing out through said tapping orifice (2) of said crucible (1). In the continuous melting apparatus, with employing a melting method of burner heating type which is inexpensive, easy to handle and maintenance, with successfully minimizing oxidation loss which was the shortcoming of the burner type. Also, generation of corundum on the furnace wall surface due to reaction of the aluminum melt and the furnace wall can be successfully avoided.

Abstract: A colored refractory material for lining an instrument/apparatus used at a high temperature is formed by mixing a powder of a raw material containing ceramics with a coloring agent and kneading with a liquid using a binder. The refractory material is put in lining for a portion being in contact with a high temperature molten substance or being exposed to a high temperature atmosphere, and is dried by heating while adjusting a temperature and a heating time on the basis of color change on the surface of the refractory material.

Abstract: Improvements in the method of applying monolithic refractory material by spraying wherein, the work surface to be lined is surrounded by a screening member such as wire nettings having suitable air escape openings, and the refractory material is sprayed within the surrounding to form a lining.Material loss due to scattering may be minimized and the work environment may be substantially improved by virtue of the screening member, and a rigid and strong refractory lining of required thickness can be obtained.

Abstract: An immersion nozzle for continuous casting resistant to the corrosive action of the melt and the covering material in a mold is made of a refractory material comprising a mixture of electrically conductive graphite and/or silicon carbide, at least one member selected from the group consisting of alumina, zircon, zirconia, fused silica and a metallic silicon, and a binder. The nozzle is covered with a thermal insulating cover having a thickness of approximately 60 mm and made of fused silica containing fibers. The nozzle is preheated without moving it from its operating position by connecting a pair of electrical terminals to opposite ends thereof and passing electric current through the nozzle between the terminals for a period of time sufficient to raise the temperature of the nozzle sufficiently to prevent cracking, spalling, etc. during casting operation. After the preheating is completed the terminals may be removed from the nozzle.

Abstract: A guide trough for molten products comprising an elongated body made of monolithic refractory material. A runway for conducting molten products is formed in the top surface of the elongated body, and a pair of reinforcing beams are embedded within the elongated body extending longitudinally thereof on opposite sides of the runway and proximate the top surface in which the runway is formed. Cross-members are spaced apart longitudinally of the elongated body and extend across the bottom thereof for interconnecting the reinforcing beam. Recesses in the elongated body expose portions of the reinforcing beams to render accessible portions of the reinforcing beams to allow them to be engaged, in use, by hooks for lifting the guide trough.

Abstract: An active silicon carbide powder containing a boron component, which contains the boron component as boron carbide or as a solid solution thereof in a uniformly dispersed state in an amount of about 0.2 to 10 wt %, calculated as boron carbide and a process for producing the same.

Abstract: A process for producing a .beta.-silicon carbide powder is disclosed wherein a ternary mixture of carbon, silicon and silica powders mixed in amounts falling within the region defined by the points O, P, Q and R in the FIGURE are reacted in an oxidizing atmosphere.

Abstract: A refractory composition for flow casting, comprising (1) 100 parts by weight of a refractory material and (2) about 1.15 to 9.4 parts by weight of a binder consisting of an alkali metal silicate, sparingly water-soluble aluminum tripolyphosphate and at least one of an organic paste and a clay, the refractory composition being capable of being kneaded with water prior to use.

Abstract: A process for producing a powder of .beta.-type silicon carbide, which comprises heating at a temperature of about 800.degree. to about 1,400.degree. C a mixture of a carbon powder having a particle size of about 20 microns or less and a metallic silicon powder with a carbon-to-silicon molar ratio of 1 : 0.6 to 1 : 2 in an oxidizing atmosphere having an oxygen concentration of 0.3 to 35% by volume, thereby to induce a spontaneous continuous reaction between carbon and silicon.

Abstract: A monolithic refractory material especially suitable for vibration forming comprising a refractory composition containing silica sol, alumina sol or both as a binder and a water-insoluble or slightly water-soluble phosphate. The refractory material is used for lining receptacles such as a ladle or tundish or a trough or the like for treating molten metals.

Abstract: A method of making an immersion nozzle or a long stopper, which comprises kneading 3 to 15% by weight of a binder capable of forming a carbon bond upon burning to decompose the binder in a reducing atmosphere with a granular material consisting of 48 to 82% by weight of zircon sand, 10 to 35% by weight of natural flake graphite and 1 to 8% by weight of silicon; molding the kneaded mixture using an isostatic press at a pressure of 500 to 1500 kg/cm.sup.2 ; burning the molded product in a reducing atmosphere at a temperature of 900.degree. to 1200.degree. C; and applying a glassy coating to the outer surface of the burned product.