Abstract: A re-usable alumina-magnesia graphite refractory suitably used for a refractory for continuous casting, such as a long nozzle used for pouring a molten metal from a ladle capable of re-use or intermittent use to a tundish, an immersion nozzle used for charging a molten metal from a tundish to a mold and a long stopper for controlling the flow rate of the molten steel; and produced by blending 3 to 60 wt % of magnesia having a particle size of 0.02 to 1.0 mm to a compound comprising mainly alumina and graphite, and kneading, molding, and baking the compound. The raw material compound comprising mainly alumina and graphite can contain spinel or zirconia.

Abstract: A refractory protective block protects heat exchange means connecting tubes to fins. The refractory protective block has an inside complementary shape corresponding to the surface shape of the heat exchange means and the refractory protective block is provided with recesses into which projections formed on the tubes are fitted and received. A pair of projections formed on the two adjacent tubes in the heat exchange means are arranged so as to confront each other. The refractory protective block has a high durability which does not break even when heat exchange means expand more than the refractory block at the time of the repetition of heating and cooling and which enable the dispersion of strain at the time of the repetition of expansion and contraction.

Abstract: A castable refractory which comprises a matrix, making up 100 wt % in total, composed of 3-20 wt % of magnesia clinker having a particle diameter smaller than 0.21 mm and containing more than 95 wt % of MgO and 0.5-3.0 wt % of alumina cement in terms of CaO, with the remainder being alumina, and 0.1-3 wt % of ultrafine powder of amorphous silica and 41-100 wt % of alumina coarse grains having a particle diameter of 10-50 mm, both in terms of outer percentage of the amount of the matrix.

Abstract: A castable refractory which comprises a matrix, making up 100 wt % in total, composed of 3-20 wt % of magnesia clinker having a particle diameter smaller than 0.21 mm and containing more than 95 wt % of MgO and 0.5-3.0 wt % of alumina cement in terms of CaO, with the remainder being alumina, and 0.1-3 wt % of ultrafine powder of amorphous silica and 3-9 wt % of alumina coarse grains having a particle diameter of 8-20 mm, both in terms of outer percentage of the amount of the matrix.

Abstract: A surface pressure loading and releasing mechanism in a sliding nozzle device for a molten metal vessel is used to reduce the hot manual work involved in loading and releasing surface pressure on plates and to carry out loading and releasing of the surface pressure by a simple operation. In a sliding nozzle device for applying and releasing surface pressure between plate bricks by moving an opening/closing metal frame having elastic force loading and a sliding metal frame disposed between a fixed metal frame and the opening/closing metal frame, a surface pressure block is removably disposed between brackets for mounting the opening/closing metal frame on the fixed metal frame. Surface pressure loading and releasing is carried out by moving the opening/closing metal frame, by causing a projecting portion of the sliding metal frame to project into the opening/closing metal frame, and by having a molten steel passage hole in the sliding metal frame passing therethrough abut with the opening/closing metal frame.

Abstract: A casting nozzle joint structure capable of easily positioning and jointing a nozzle without any holder for fixing and supporting a continuous casting nozzle therethrough. The joint structure comprises fitting mechanism formed in and on the mating faces of the continuous casting nozzle and the pressure clamper. The fitting mechanism includes a convex portion and a concave portion formed in and on the mating faces of the continuous casting nozzle and the pressure clamper so that they fit one another. The concave or convex portion formed in the mating face of the continuous casting nozzle is fitted on or in the convex or concave portion formed in the mating face of the pressure clamper, and this pressure clamper clamps the fitted engagement. Thus, the nozzles can have their outlet bores positioned, and the submerged entry shroud can have its discharge port oriented.

Abstract: The present invention is intended to provide a heat-insulating refractory material, which does not contain environmentally and hygienically undesirable ceramic heat-insulating fibers, but only contains organic fibers to the extent necessary to improve adhesive rate upon spraying, and which can nevertheless achieve a specified heat-insulating effect. The heat-insulating refractory material includes a mixture containing 2-50 wt % of a foaming raw material foamed by heat at a temperature from 400.degree. to 1500.degree. C. and 50-98 wt % of a refractory powder, and a liquid binder which is added to the mixture in an amount of 20-250 wt % on the basis of the weight of the mixture.

Abstract: A sliding nozzle plate-metal frame fixing structure which allows the sliding nozzle plate to be mounted to and removed from the metal frame with ease. The sliding nozzle plate which is used with a sliding nozzle device attached to a molten metal vessel has a sliding surface, and is surrounded by a metal case with the exception of the sliding surface. The metal case has a projection or a plurality of projections of a particular shape on the surface of the plate opposite the sliding surface, and a metal frame in which the metal-cased plate to be mounted has a plurality of concave portions corresponding to the projection or projections of the metal case, so that the metal-cased plate can be mounted to and removed from the metal frame simply and accurately through engagement and disengagement of each of the metal case projection or projections with each of the metal frame concave portions.

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.

Abstract: A catalyst for exhaust gas purification, comprising a heat-resistant inorganic monolith carrier and a catalyst layer loaded thereon, the catalyst layer including a catalyst composition containing at least one noble metal selected from Pt, Pd and Rh, as an active catalyst component, and active alumina. The catalyst composition has a specific surface area of at least 50 m.sup.2 /g and a porosity of at least 50%. This catalyst for exhaust gas purification contains noble metal(s) in a well dispersed state, has excellent high-temperature durability, and is low in thermal deterioration of catalyst performance. Hence, the catalyst can be suitably used as a converter installed in engine manifolds of gasoline engine automobiles, or as a heater having improved purification ability for the exhaust gases emitted from automobiles during their cold start.

Abstract: Disclosed is a phenol-formaldehyde resin binder for refractories, having from 0.05 to 0.6 methylol group on average per one phenolic constitutive unit and having a free phenol content of less than 5%. For producing refractory granules with the binder, a composition comprising carbon substances of 50% by weight or less in all and a balance of refractory substances is kneaded with the binder and water optionally along with a solvent having a boiling point of 200.degree. C. or higher, in a mixer as heated at 60.degree. to 130.degree. C. Optionally, the volatile content in the blended mix is adjusted to the shapable level. The process of using the binder is free from injury to human bodies and the danger of firing. The refractory granules may be shaped into refractory articles having a suitable gas-permeability stable against variation of the working environment. The refractory granules are suitable for shaping gas-blowing immersion nozzles having a suitable gas-permeability.

Abstract: Disclosed herein are a refractory material of high-purity electrofused magnesia clinker having good resistance to corrosion by slag, especially the slag with a high iron content, at high temperatures under an oxidative environment, and a burned or unburned refractory brick made of such refractory material of high corrosion resistance, which is superior in corrosion resistance as well as spalling resistance.The refractory material comprises more than 10 wt. % of electrofused magnesia clinker containing 98.0 to 99.8 wt. % of MgO, less than 0.05 wt. % of SiO.sub.2, and 0.1 to 2.0 wt. % of CaO. It may be in the form of burned or unburned or prepared unshaped refractories.

Abstract: Basic monolithic refractories of which the chemical composition consists essentially of, in oxide equivalence, 65%-96% by weight of MgO, 2.6%-20% by weight of ZrO.sub.2, 1.3-10% by weight of SiO.sub.2, 2% or less by weight of CaO, 0.5% or less by weight of Fe.sub.2 O.sub.3 and 1% or less by weight of Al.sub.2 O.sub.3, and with a mineral composition containing periclase as the main component and cubic zirconia and forsterite as sub-components, and with apparent porosity of 7% or less and bulk density of 3.2 g/cm.sup.3 or more.Basic monolithic refractories under this invention possess excellent slaking resistance, slag erosion resistance, slag penetration resistance and spalling resistance. They exhibit an excellent service life, especially as lining material for steel-making furnaces.

Abstract: A ceramic plate having three dimensional reticulated pores is secured to a metal frame comprising drain holes at the bottom, so that the mechanical strength of the filter is improved, handling thereof is easier, and drainage and drip thereof are easily performed.