A method of separating a mixture of used refractory components of different chemistry types obtained from a demolished refractory includes hydrating the mixture of refractory components to destructively hydrate at least some components of the mixture of refractory components, and separating, based on size, the at least some components from other components of the mixture of refractory components.

Provided is a ZrO.sub.2—CaO—C based refractory material which is capable of maintaining high adhesion resistance over a long period of time, while exhibiting significant slaking resistance, and suppressing self-fluxing, i.e., exhibiting corrosion-erosion resistance. The refractory material comprises a CaO—ZrO.sub.2 composition containing a CaO component in an amount of 40% by mass to 60% by mass, wherein a mass ratio of the CaO component to a ZrO.sub.2 component is 0.67 to 1.5, and wherein the CaO—ZrO.sub.2 composition includes a eutectic microstructure of CaO crystals and CaZrO.sub.3 crystals, wherein a width of each of the CaO crystals observable in a cross-sectional microstructure is 50 μm or less.

A coating composition is described, for use in the foundry, in particular comprising particulate, amorphous silicon dioxide (SiO.sub.2) and an aqueous phase having a pH of at most 5, and also coated, waterglass-bound foundry molding elements, especially coated, waterglass-bound foundry molds and foundry cores, which each comprise a coating composition of the invention. Further described is the use of a coating composition of the invention for producing a coating on a waterglass-bound foundry molding element and a method for producing a waterglass-bound foundry molding element (mold or core) coated with a water-containing refractory coating. Likewise specified is a kit whose contents include a coating composition of the invention.

Sized molds for metal casting are obtained from molding material mixtures on the basis of inorganic bonding agents containing at least one phosphatic compound and at least one oxidic boron compound, especially sized, water glass-bound forms and cores, having at least one refractory base molding material, water glass as inorganic bonding agent and amorphous particulate silicon dioxide and one or more powdery oxidic boron compounds and one or more phosphatic compounds. The invention furthermore relates to a method for producing sized foundry mold bodies and use thereof, in particular for producing cast parts from iron alloys. The sizing is a water-based sizing.

A method of producing a graphite-containing refractory within which carbon fiber bundles are placed, the graphite constituting 1% to 80% by mass, the method including a bundling step of bundling carbon fibers to form the carbon fiber bundles; a mixing step of mixing a refractory raw material with graphite to prepare a graphite-containing refractory raw material; a pressing step of pressing the graphite-containing refractory raw material in which the carbon fiber bundles are placed to prepare a formed product; and a drying step of drying the pressed product, wherein the bundling step includes bundling 1000 to 300000 of the carbon fibers with a fiber diameter of 1 to 45 μm/fiber to form carbon fiber bundles 100 mm or more in length.

A spiral-orifice ceramic filter for metal casting, including spiral channels and two drain openings, where the spiral channels are distributed in a ceramic substrate in a staggered manner. By adoption of the spiral channel structure, molten metal may rotate to generate a centrifugal force while flowing forwards so as to promote separation of inclusions. The spiral-orifice ceramic filter for metal casting includes the following components: 90-95 wt % of MgO, 4-8 wt % of SiO.sub.2 and 2-4 wt % of ZrO.sub.2. Therefore, the spiral-orifice ceramic filter for metal casting has high strength under normal temperature and optional thermal impact resistance under high temperature, and may tolerate the impact of molten metal at 1700° C. or higher without break. The ceramic substrate and the spiral channel are superficially coated with one layer of functional oxide prepared from CaO.2Al.sub.2O.sub.3, CaO.6Al.sub.2O.sub.3, Al.sub.2O.sub.3, TiO.sub.2, or Re.sub.2O.sub.3.

A metering device (10) for withdrawing and dispensing a melt consisting of or containing an oxide fibre reinforced oxide ceramic composite material.

A titanium-containing calcium hexaaluminate material and preparation method thereof is disclosed. The technical solution is: using 60˜80 wt % alumina micro powder, 5˜20 wt % calcium-containing micro powder, 10˜20 wt % titania micro powder and 1˜10 wt % manganese oxide micro powder as raw materials, blending the raw materials evenly in a planetary ball mill to obtain a blend, machine pressing the blend at 100˜200 MPa to obtain a green body, drying the green body at 110˜200° C. for 12˜36 h, and incubating the dried green body at 1500˜1800° C. for 1˜8 h to obtain the titanium-containing calcium hexaaluminate material. The present disclosure has low cost and simple process, and the prepared titanium-containing calcium hexaaluminate material has the characteristics of good chemical stability, high thermal shock resistance and strong melt resistance to titanium-aluminum alloy.

Provided is a hearth roll for supporting and conveying a steel sheet in a continuous annealing furnace, wherein all of a shaft portion and a roil main body are made from one or more ceramic materials, preferably constituted with concentric ceramic layers of different ceramic materials centering on the rotation shaft of the roll. The hearth roll has not only an excellent pickup resistance but also a long roll life free from maintenance for long periods. Also provided is a continuous annealing facility using the hearth roll in at least one of a heating zone, a soaking zone and a cooling zone.

A molten metal processing apparatus selected from a pump, a degasser, a flux injector, and a scrap submergence device constructed to include at least one element comprised of C/C composite.