The invention relates to a method for treating magnesia-carbon products.

Thermoset ceramic compositions and a method of preparation of such compositions. The compositions are advanced organic/inorganic hybrid composite polymer ceramic alloys. The material combines strength, hardness and high temperature performance of technical ceramics with the strength, ductility, thermal shock resistance, density, and easy processing of the polymer. Consisting of a branched backbone of silicon, and alumina, with highly coordinated Si—O—Si or Al—O—Al bonds, the material undergoes sintering at 7 to 300 centigrade for 2 to 94 hours from water at a pH between 0 to 14, humidity of 0 to 100%, with or without vaporous solvents.

Provided are a Kanbara Reactor (KR) desulfurization stirring paddle casting material and a preparation method therefor. The casting material consists of a base material and an additive; the base material consists of the following raw materials in weight percentages: M70 sintered mullite 60-80%, flint clay 5-20%, fine powder 5-20%, and pure calcium aluminate cement 1-5%. The percentages of each component of the additive based on the weight of the base material are as follows: water reducing agent 0.05-0.2%, and heat-resistant stainless steel fiber 1-5%. The main raw materials are M70 sintered mullite and a small amount of flint clay so as to ensure good thermal shock resistance; the medium temperature and high temperature strength are controlled at 100-180 MPa so as to ensure good erosion resistance; the content of Al.sub.2O.sub.3 in the casting material is 60-70% so as to ensure good corrosion resistance; the ratio of high temperature strength to medium temperature strength is controlled at 1-1.2, which further improves the thermal shock resistance and peeling resistance of the casting material, thereby extending the service life of the stirring paddle. The casting material is lower in cost and has a good practical furnace usage effect; in addition, a paddle blade has less chance of cracking and peeling, while a bottom portion of the stirring paddle is less eroded, thus the frequency of paddle blade repair is low, and service life is significantly improved.

An unfired, refractory molded body (1), especially a plate, especially for thermal insulation of molten metal and/or an ingot solidifying from molten metal, that includes a binding agent matrix (2) of a set binder and aggregate grains (3) of biogenic silicic acid, preferably of rice husk ash, which are incorporated into the binding agent matrix (2), wherein the binding agent matrix (2) consists of silica gel, as well as a process for its production and its usage.

A method for producing a sand mold includes mixing artificial sand with a furan resin composition including a furan resin precursor, preparing molding sand having the artificial sand and a surface-modified layer containing a resin cured product covering the artificial sand and including a curing agent attached to the surface-modified layer by mixing the curing agent including xylene sulfonic acid with the artificial sand with which the furan resin composition is mixed, and curing the furan resin composition, after mixing the artificial sand with the furan resin composition, and curing an added portion of the binder in the molding sand by adding the binder to the molding sand. In the step of curing the added portion of the binder, the curing agent for curing the furan resin composition is used also as a curing agent for curing the binder.

A self-bonding refractory powder product for use in making a slurry for investment casting molds comprising a coarse refractory powder; a Nano-sized powder; and an organic polymer powder, wherein it does not require aqueous colloidal silica to produce slurries used to build investment casting molds. The Nano-sized powder comprises fumed alumina, boehmite, fumed silica, or fumed titanium oxide or combinations thereof. The coarse refractory powder comprises milled zircon, tabular alumina or fused alumina, fused silica, alumino-silicate, zirconia, and yttria or combinations thereof. The organic polymer powder comprises a cellulose-based material.

A sand additive for use in a “no bake” foundry mix composition having a polyurethane-based binder system reduces the amount of smoke emitted when molds and cores formed from the composition are exposed to molten metal, as compared to when the sand additive is not used. The sand additive comprises yellow iron oxide having the chemical formula Fe(OH).sub.3. It can also comprise at least one of red iron oxide, black iron oxide and wüstite. In such cases, the yellow iron oxide accounts for about 10 to about 40 weight percent of the combined weight of the yellow iron oxide, red iron oxide, black iron oxide and wüstite, and preferably, about 20 to about 30 weight percent of the combined weight of the yellow iron oxide, red iron oxide, black iron oxide and wüstite.

Provided are a binder in the producing of a casting sand mold according to an ink jet type lamination shaping method in which a binder is printed with respect to sand, a method for producing the binder, and a method for producing a casting sand mold using the binder. Specifically, provided are a binder useful for a casting sand mold of an ink jet type, containing: a resol-type phenolic resin that is obtained by reacting aldehydes (A1), phenols (P1), and a compound (N) having two or more phenolic hydroxyl groups in one molecule or by reacting the aldehydes (A1) and a novolac-type phenolic resin (N1), in the presence of an alkali catalyst, and has a dispersion degree (Mw/Mn) of 1.0 to 3.5 and a phenolic monomer residue of 5% or less, a method for producing the binder, and a method for producing a casting sand mold.

A ceramic foam filter and a manufacturing method thereof. The ceramic foam filter comprises the following materials provided in respective weight percentages: 20-50% of a silicon carbide, 20-55% of a zirconium oxide, and 10-36% of a silicon oxide, wherein all figures are based on the total weight of the ceramic foam filter. The method for manufacturing the ceramic foam filter comprises the following steps: (a) providing a slurry comprising a silicon carbide, a zirconium oxide or zirconium oxide precursor, a silicon oxide or silicon oxide precursor, a binder, an optional additive, and a fluid carrier medium; (b) applying the slurry to perform surface ornamentation of a perforated organic foam; (c) drying the perforated organic foam surface ornamented with the slurry to obtain a green body; and (d) sintering the green body in oxygen-containing air to obtain the ceramic foam filter.

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.