Abstract: A high-chromia refractory, comprised of: about 60% to about 99% by weight of refractory grain, wherein the refractory grain is comprised of grains having about 20% to 100% by weight chromia; 0% to about 35% by weight of a fine particulate, the fine particulate selected from chromic oxide, alumina, ceria, yttria, lanthanum oxide, or combinations thereof; and about 1% to about 8% of a liquid resin or pitch.

Abstract: A sintered product presenting a mean chemical composition such that, in percentages by weight based on the oxides: Cr2O3: 72.0%-98.9% 2%<Al2O3?20% 0.1%?TiO2?6.0% ZrO2<4.0% SiO2?0.9%.

Abstract: An article which includes a structure of a ceramic material that has a composition SiOxMzCy, where Si is silicon, O is oxygen, M is at least one metal and C is carbon and wherein x<2, y>0 and z<1 and x and z are non-zero.

Abstract: A treated refractory material includes a porous refractory material having one or more protective materials disposed within pores of the refractory material. Methods of preparing the treated refractory material are also provided. The treated refractory material provides protection from the penetration of slag and extends the service life of the refractory material.

Abstract: A thermistor based on a composition having the general formula (I): Re2-x-yCraMnbMcEyOz wherein Re is a rare earth metal or a mixture of two or more rare earth metals, M is a metal selected from the group consisting of nickel, cobalt, copper, magnesium and mixtures thereof, E is a metal selected from the group consisting of calcium, strontium, barium and mixtures thereof, x is the sum of a+b+c and is a number between 0.1 and 1, and the relative ratio of the molar fractions a, b and c is in an area bounded by points A, B, C and D in a ternary diagram, wherein point A is, if y<0.006, at (Cr=0.00, Mn=0.93+10?y, M=0.07?10?y), and, if y?0.006, at (Cr=0?00, Mn=0.99, M=0.01), point B is, if y<0.006, at (Cr=0.83, Mn=0.10+10?y, M=0.07?10?y), and, if y?0.006, at (Cr=0.83, Mn=0.16, M=0.01), point C is at (Cr=0.50, Mn=0.10, M=0.40) and point D is at (Cr=0.00, Mn=0.51, M=0.49), y is a number between 0 and 0.5?x, and z is a number between 2.5 and 3.5.

Abstract: The invention provides a sintered product presenting an apparent density greater than 4.00 g/cm3 and having the following mean chemical composition, as a percentage by weight based on the oxides and for a total of 100%: Al2O2: complement to 100% 16%?Cr2O3?29.5% TiO2 in a quantity such that the Cr2O3/TiO2 weight ratio is greater than 16 and less than 35, other species: ?1% Application as an electrode bushing block.

Abstract: A gasifier comprising an interior wall on which a layer is applied or an interior wall protected by an assembly of blocks, said layer or said blocks having at least one region of a sintered material containing: i) at least 25% by weight of chromium oxide Cr2O3; and ii) at least 1% by weight of zirconium oxide, wherein at least 20% by weight of said zirconium oxide ZrO2 is stabilized in the cubic and/or quadratic form.

Abstract: There is described a two-Level Layer System with Pyrochlore Phase and Oxides. Besides a good thermal insulation property, thermal insulation layer systems must also have a long lifetime of the thermal insulation layer. The layer system has a layer sequence of a metallic bonding layer, an inner ceramic layer and an outer ceramic layer, which are specially matched to one another.

Abstract: A high-chromia refractory, comprised of: about 60% to about 99% by weight of refractory grain, wherein the refractory grain is comprised of grains having about 20% to 100% by weight chromia; 0% to about 35% by weight of a fine particulate, the fine particulate selected from chromic oxide, alumina, ceria, yttria, lanthanum oxide, or combinations thereof; and about 1% to about 8% of a liquid resin or pitch.

Abstract: A refractory composition comprising at least 50 weight percent chromic oxide (Cr2O3), as measured by chemical analysis. The composition includes fused chromia-containing grain, powdered chromic oxide and sintered chromia-containing grain. The fused chromia-containing grain and the sintered chromia-containing grain comprise at least 50 weight percent chromia oxide, as measured by chemical analysis.

Abstract: A treated refractory material includes a porous refractory material having one or more protective materials disposed within pores of the refractory material. Methods of preparing the treated refractory material are also provided. The treated refractory material provides protection from the penetration of slag and extends the service life of the refractory material.

Abstract: A refractory composition comprising at least 50 weight percent chromic oxide (Cr2O3), as measured by chemical analysis. The composition includes fused chromia-containing grain, powdered chromic oxide and sintered chromia-containing grain. The fused chromia-containing grain and the sintered chromia-containing grain comprise at least 50 weight percent chromia oxide, as measured by chemical analysis.

Abstract: The invention relates to a fired refractory ceramic product. According to the invention, this generic term encompasses both shaped and unshaped products. Shaped products are ones which have a defined shape so that they can be manufactured in finished form on the premises of the manufacturer. Shaped products include: bricks, nozzles, tubes, stoppers, plates, etc. The term unshaped products includes ones which are usually produced by the user from a corresponding composition. They include bases for furnaces which are cast from a composition but also repair compositions, etc.

Abstract: A composition includes particles of an inorganic component A and particles of an inorganic component B which together can form a eutectic system and react at least partly with one another at a sintering temperature, resulting in formation of at least one ternary chemical compound of the spinel type. The composition can be applied to high-temperature-stable ceramic layers, coatings and shaped bodies and also their production, their uses and compositions for producing them.

Abstract: A method includes contacting a transition metal oxide, a sintering additive, and a grain growth inhibitor additive to form a mixture. The transition metal oxide include particles that have an average diameter less than about 1 micrometer and sintering the mixture to a temperature profile that is sufficiently high that a sintered mass is formed from the mixture. The sintering includes at least one of a microwave sintering or a spark plasma sintering. The thermal profile is less than about 1050 degrees Celsius.

Abstract: The present invention is directed to a noise suppressor for electronic signals. The noise suppressor at least includes Aluminum Oxide (Al2O3) that is sintered under high temperature, resulting in ceramic Aluminum Oxide (Al2O3) for effectively absorbing or suppressing noise, and reshaping the waveform or filtering waveform glitch of the electronic signals.

Abstract: The instant invention relates to a process and plant for the transformation of dangerous wastes containing chromium six as contaminant into non dangerous wastes that can be stored without special care and will be degraded in the environment without time limit. The process basically consists of milling, extracting chromium six in liquid phase and under controlled conditions of stirring, time and temperature, proceeding then, through reduction, to transform the chromium six in chromium three and then precipitating as chromium trioxide, through gasification. The solid resulting from the transformation process can be used as raw material for the manufacturing of firebricks or eventually for the manufacturing of bricks used in the building industry through a process not included in the instant description.

Abstract: The present invention relates to a green ceramic coating composition, the composition comprises nano-sized particles dispersed within a carrier medium together with preformed particles. The composition optionally comprises an infiltration medium.

Abstract: A porous catalyst layer containing mixed conducting oxide having substantially a perovskite structure and containing a first element selected from Co and Fe, and a second element selected from In, Sn and Y arranged in the B site in the perovskite structure is contiguous to a second surface (1a) of a selective oxygen-permeable dense continuous layer (1) containing mixed conducting oxide. A porous intermediate catalyst layer (3) containing mixed conducting oxide and at least one of Co, Fe, Mn and Pd is contiguous to a first layer (1b) of the dense continuous layer (1). A porous reactive catalyst layer (4) provided with a metal catalyst selected from at least one of Ni, Co, Ru, Rh, Pt, Pd, Ir and Re and a support is continguous to the porous intermediate catalyst layer (3) in a manner to sandwich between the dense continuous layer (1) and the porous reactive catalyst layer (4).

Abstract: Particles particularly useful for thermal spraying a wear resistant coating on to a substrate comprise an essentially single phase crystalline structure comprising from 45 to 99% by weight of chromia and 55 to 1% by weight of alpha alumina.

Abstract: A fired spinel complex oxide is produced by firing a mixture containing a slag by-produced in chromium refining, a reducer, and a silica-containing material, and is essentially composed of: 29 to 40 percent by weight of Fe2O3; 15 to 20 percent by weight of Al2O3; 9 to 14 percent by weight of MgO; 0 to 4 percent by weight of Na2O; 9 to 17 percent by weight of Cr2O3; 14 to 20 percent by weight of SiO2; and 2 percent by weight or less of CaO. The fired spinel complex oxide shows a Cu—K? X-ray diffraction pattern in which the ratio (b/a) of the diffraction peak intensity of the silica-containing material (b) in the vicinity of 2?=26.7° to the {113} plane diffraction peak intensity (a) in the vicinity of 2?=36° is 0.1 or less.

Abstract: A refractory repair batch material includes a refractory, in particular a basic resistor component in granule form and a binder system. The binder system contains at least one hard bitumen component in granule form, at least one ignitable metal powder and at least one combustible mineral oil.

Abstract: Particles particularly useful for thermal spraying a wear resistant coating on to a substrate comprise an essentially single phase crystalline structure comprising from 45 to 100% by weight of chromia and from 0 to 55% by weight of alpha alumina.

Abstract: A microstructured or nanostructured multi-component ceramic comprises (a) a major ceramic phase comprising a ceramic oxide composite; (b) a ceramic oxide additive; and (c) a rare earth ceramic oxide additive, wherein the total of the additives (b) and (c) comprise from about 0.1 weight percent to less than 50 weight percent based on the total weight the multi-component ceramic composite. In another embodiment, a microstructured or nanostructured multi-component ceramic comprises (a) a major ceramic oxide phase comprising a ceramic oxide composite; and either (b) a ceramic oxide additive or (c) a rare earth ceramic oxide additive, wherein amount of the additive (b) or (c) comprises from about 0.1 weight percent to less than 50 weight percent based on the total weight the multi-component ceramic composite. Such ceramics are useful as bulk materials or as feedstocks for thermal spray.

Abstract: The invention relates to free-flowing refractory castable material and castings produced therefrom. Refractory nonbasic and basic refractory castable materials have been known for a long time. The traditional refractory castable materials have thixotropic properties and must be lined sing vibration technology. In the past, free-flowing refractory castable materials were solely based on alumina raw materials. Attempts to produce an aqueous, highly concentrated basic suspension which would Coma the basis of free-flowing refractory castable materials failed to meet the requirements in terms of theological properties and a low degree of to hydration of the MgO-based materials. It is the aim of the invention to provide the above-mentioned refractory castable material for the monolithic lining or repair of high-temperature equipment and for the production of refractory castings. This is achieved by providing a fine-grained and a mixed fine and coarse-grained alternative.

Abstract: A microstructured or nanostructured multi-component ceramic comprises (a) a major ceramic phase comprising a ceramic oxide composite; (b) a ceramic oxide additive; and (c) a rare earth ceramic oxide additive, wherein the total of the additives (b) and (c) comprise from about 0.1 weight percent to less than 50 weight percent based on the total weight the multi-component ceramic composite. In another embodiment, a microstructured or nanostructured multi-component ceramic comprises (a) a major ceramic oxide phase comprising a ceramic oxide composite; and either (b) a ceramic oxide additive or (c) a rare earth ceramic oxide additive, wherein amount of the additive (b) or (c) comprises from about 0.1 weight percent to less than 50 weight percent based on the total weight the multi-component ceramic composite. Such ceramics are useful as bulk materials or as feedstocks for thermal spray.

Abstract: A chromium catalyst is disclosed for use in dehydrogenation and dehydrocyclization processes.

Abstract: This invention relates to processes for the production of a sintered body consisting of an intimate solid solution of Cr2O3 and Al2O3 by using inexpensive materials, as well as sintered bodies produced thereby. More specifically, it relates to processes for the production of a sintered body which comprises the steps of providing a powder mixture consisting essentially of Cr2O3 powder and Al2O3 powder each having an average particle diameter of not greater than 0.5 &mgr;m, or a powder mixture obtained by mixing the aforesaid powder mixture with 1.5 to 15% by weight of TiO2 powder having an average particle diameter of not greater than 0.5 &mgr;m, and sintering the powder mixture at a temperature of 1,350 to 1,600° C. in a vacuum atmosphere of 10−20 to 10−5 atm. to yield a sintered body consisting of an intimate solid solution of Cr2O3 and Al2O3 and having a relative density of not less than 95%, as well as sintered bodies produced thereby.

Abstract: The invention concerns a refractory material based on chromium corundum, a chromium corundum brick made of said material as well as the use thereof.

Abstract: A filler sand for a ladle tap hole valve contains 70 to 90 wt % of chromite sand and 10 to 30 wt % of silica sand and is blended externally with 0.05 to 5 wt % of carbon black calculated based on the total amount of the chromite sand and the silica sand; or contains 70 to 90 wt % of chromite sand and 10 to 30 wt % of silica sand, wherein the chromite sand has a particle diameter distribution such that 99% or more of the chromite sand consists of particles having diameters ranging from 150 to 850 &mgr;m and that 95% or more of the chromite sand consists of particles having diameters ranging from 200 to 600 &mgr;m, and the silica sand has a particle diameter distribution such that 95% or more of the silica sand consists of particles having diameters ranging from 150 to 850 &mgr;m and that 80% or more of the silica sand consists of particles having diameters ranging from 200 to 600 &mgr;m.

Abstract: Disclosed is a molding method for powder particles, which is excellent in molding performance, and which makes it possible to obtain a preliminary molded product excellent in strength by enhancing mutual bonding between particles in the preliminary molded product. A molding apparatus for powder particles includes an outer frame die having a mold space with a lower punch and an upper punch to be slidably fitted thereto. Slight clearances exist between the outer frame die and the lower and upper punches. A mixture is prepared by mixing a powdery raw material with a liquid additive to cause an exothermic reaction therewith.

Abstract: A roll for use in the manufacture of paper and board, a press roll, in particular a center roll in a press, a backup roll for an extended-nip press roll, a hot press roll, or equivalent, which is in direct contact with a wet paper web, or a calender roll, a method for manufacturing the same and a coating composition therefor including an adhesion layer arranged on the frame part of the roll and a ceramic layer arranged on the adhesion layer. The ceramic layer has a thickness of from about 100 &mgr;m to about 2000 &mgr;m and includes from about 50% to about 95% by weight of Cr2O3 and from about 3% to about 50% by weight of TiO2, or from about 50% to about 80% by weight of Al2O3 and from about 20% to about 50% by weight of ZrO2, or exclusively Al2TiO5. The outer face of the ceramic layer is finished until the roughness Ra is from about 0.2 &mgr;m to about 2.0 &mgr;m and/or the porosity of the outer face of the roll is from about 1% to about 20%.

Abstract: A multi-phase solid electrolyte ion transport membrane comprising at least two phases wherein one of the phases comprises an oxygen ion single conductive material, or a mixed conductor. The other phase comprises an electronically-conductive metal or metal oxide that is incorporated into the membrane by deposition of the metal or metal oxide from a polymer made by polymerizing a chelated metal dispersion in a polymerizable organic monomer or prepolymer. The multi-phase composition advantageously comprises a first phase of a ceramic material and a second phase of a metal or metal oxide bound to a surface of the ceramic material. The multi-phase composition is advantageously prepared in an in-situ fashion before fabricating the membrane matrix. As another alternative, a preformed ceramic matrix is surface-coated with a metal or metal oxide.

Abstract: The present invention relates to rare earth elemental thermistors and compositions useful for making such thermistors. In particular, it relates to yttrium and chromium oxide based thermistor systems having at least two phases: YCrO.sub.3 and Cr.sub.2 O.sub.3 and their use for measuring temperature.

Abstract: The present invention provides a ceramic sintered body excellent in oxidation resistance under high temperatures and markedly superior to the conventional ceramic sintered body in the mechanical strength over a wide temperature range of between room temperature and 1,500.degree. C. The ceramic sintered body of the present invention comprises at least one ceramic crystal grain selected from the group consisting essentially of a monosilicate represented by the general formula RE.sub.2 SiO.sub.5, where RE denotes a IIIa group element including yttrium, and a disilicate represented by the general formula RE.sub.2 Si.sub.2 O.sub.7, where RE denotes a IIIa group element including yttrium, and at least one additional element selected from the group consisting of Al, Cr, Hf, Nb, Zr, Ti, V, Ta, Ca and Mg which is segregated in the boundaries of the ceramic crystal grains in an amount of 0.1 to 15% by weight of the sintered body in terms of the oxide thereof.

Abstract: The invention relates to the field of ceramics and concerns sintered Al.s2 O.sub.3 compositions produced from corundum powder and also methods for the use of the invented compositions as medical implants or tool material. To produce such materials, an initially unsintered precursor having a relative density of .rho..gtoreq.55% is produced from .alpha.-Al.sub.2 O.sub.3 powder having defined properties using at least two different dispersing methods, this precursor is subsequently subjected to heat treatment and sintering.

Abstract: A hard film is covered on the outer circumferential surface of a piston ring by means of an arc ion plating. The hard film has a mixture of crystal structure of CrN and crystal structure of Mo.sub.2 N containing oxygen in a solid solution state, and comprises chromium at 40 to 78 percent by weight, molybdenum at 3 to 35 percent by weight, oxygen at 3 to 20 percent by weight and the remainder of nitrogen. The crystal particle size is less than 1 .mu.m. The Vickers hardness is within a range from 1600 to 2500. The film thickness is preferably 1 to 60 .mu.m. Carbon in a solid solution state at 0.5 to 8 percent by weight may be substituted for the oxygen. Alternatively, both oxygen and carbon may be contained in a solid solution state with oxygen at 3 to 20 percent by weight, carbon at 0.5 to 8 percent by weight with the total content of carbon and oxygen within 25 percent by weight.

Abstract: A filler for a sliding gate containing 70 to 90 wt % of chromite sand and 10 to 30 wt % of silica sand in which the particle size distribution of the chromite sand is substantially from 500 to 1,000 .mu.m, which is not melted, sintered or penetrated by molten metal (molten steel) poured in a ladle in a steel works, and therefore is easily discharged to let the gate through.

Abstract: Zirconium dioxide containing 2 to 40 vol. % of stabilizing oxides is embedded in the matrix material of a sintered molding consisting of an aluminum oxide/chromium oxide mixed crystal. The quantity of stabilizing oxides added is chosen so that the zirconium dioxide is predominantly tetragonal. The molar ratio of the zirconium dioxide containing the stabilizing oxides to the chromium oxide is between 1000:1 and 20:1 and the zirconium dioxide has a maximum particle size of 2 .mu.m.

Abstract: A precursor, in gel form, of an oxide having the formula (I), BaO.n(Al.sub.2x Cr.sub.2y O.sub.3), where 1.ltoreq.n.ltoreq.6.6, (x+y)=1, and 0.ltoreq.y.ltoreq.0.5, said oxide being derivable from the precursor gel by the application of heat, is prepared by mixing a solution of a barium salt with a solution of an aluminium salt or a solution of an aluminium salt and a solution of a chromium salt, and polymerising the mixture to produce said precursor gel. A mixture suitable for firing to an oxide of the formula (II), BaO.m(Al.sub.2x Cr.sub.2y O.sub.3), where 4.6.ltoreq.m.ltoreq.6.6; (x+y)=1; and 0.ltoreq.y.ltoreq.0.5, comprises at least one of:(a) barium oxide;(b) a clean thermal precursor of barium oxide; and(c) barium mono-aluminate, BaO.Al.sub.2 O.sub.3 ; with at least one of:(A) alumina, Al.sub.2 O.sub.3 ;(B) hydrated forms of alumina, such as boehmite, Al.sub.2 O.sub.3.H.sub.2 O; and(C) a clean thermal precursor of aluminium oxide; and, where y is not zero, with at least one of(D) chromium(III) oxide, Cr.

Abstract: A certain group of electrically conductive refractory materials presently known for use in high temperature applications as throat constructions, melter sidewalls, forehearth, stacks, port sills, hot face lining for slagging coal gasifiers, slag runners, and linings for nuclear waste encapsulation furnaces may be used as electrodes permitting joule heating at temperatures in excess of 1200 C. in excess of about 4400 hours even in the presence of transition group element(s). More specifically, the invention is an electrode for melting earthen materials, wherein the electrode is made from an electrically conductive refractory material, specifically at least one metal oxide wherein the metal is selected from the group consisting of chrome, ruthenium, rhodium, tin and combinations thereof.

Abstract: The disclosed invention is directed to novel ceramic compositions, and to stabilizer compositions for use with those ceramic compositions. The ceramic materials are formed of rare earth chromium oxides that include a novel combination of stabilizing compounds. Also, dryer or sterilizer devices which incorporate these ceramic compositions for generating infrared radiation for drying or sterilizing various articles.

Abstract: Provided is a semiconductive ceramic composition comprising a lanthanum cobalt oxide and having a negative resistance-temperature characteristic, which contains, as the side component, a chromium oxide in an amount of from about 0.005 to 30 mol % in terms of chromium, and also a semiconductive ceramic device comprising the composition. The device is usable for rush current inhibition, for motor start-up retardation and for halogen lamp protection, and is also usable in temperature-compensated crystal oscillators.

Abstract: Enhancement of mechanical properties of ceramic membranes by introduction of a uniformly distributed high-temperature oxidation-resistant metal phase into the brittle ceramic phase to achieve mechanically strong ceramic/metal composites operable in an oxidation atmosphere and at elevated temperatures.

Abstract: Transparent, polycrystalline garnet bodies having desirable properties for use as laser material, luminescent x-ray scintillator materials and other uses are produced by mixing a chloride source solution of the desired cations with a basic ammonium solution to produce a precipitate having a substantially uniform composition which can be further processed to provide the desired transparent body. This precipitate is separated from the solution, dried, thermally decomposed at a temperature in the range from 700.degree. to 1,000.degree. C., pressed to form a compact, isostatically pressed at up to 60,000 psi to provide a green, unsintered compact having a density in the vicinity of 55% of theoretic density. That green compact is then sintered in oxygen at a temperature between 1,400.degree. and 1,700.degree. C. to produce the desired transparent body. Alternatively, the compact may be sintered in oxygen at temperatures in the range from about 1,400.degree. to about 1,600.degree. C.

Abstract: A ceramic composite contains one spinel phase and one or more than one oxides phases. The composite is derived from the mixtures of two oxides, A.sub.2 O.sub.3 and BO, with different molar ratio, in which A and B are metallic ions of three and two valences respectively. The oxides are heated at a high temperature to form a composite containing a spinel and residual oxides. The formed spinel and residual oxides also undergo densification under high temperature. After the treatment at high temperature, not only the spinel is formed but also the composite is densified. The performance of the composite is superior in its strength, toughness and high-temperature stability.

Abstract: An oxide type solid lubricant is formed of a powder of a fired composite ceramic material resulting from heating a mixture of BaZrO.sub.3 and Cr.sub.2 O.sub.3 powders in which the Cr.sub.2 O.sub.3 content is up to 80% by weight.

Abstract: An article of manufacture has as its basic structure a piece of a titanium aluminide, such as gamma (TiAl) or alpha-2 (Ti3Al), desirably in the shape of an aircraft gas turbine component. A thermal barrier coating system overlies at least a portion of the surface of the piece of titanium aluminide. The thermal barrier coating system includes a metallic bond coat layer, preferably in the form of a layer of a nickel-based alloy no more than about 0.005 inches thick, that contacts the piece of titanium aluminide, and a ceramic thermal barrier coating layer, preferably a stabilized zirconia such as yttria-stabilized zirconia, overlying the bond coat.

Abstract: In ceramic welding processes, oxidizing gas and a mixture of refractory and fuel powders are projected against a surface and the fuel is burnt to generate sufficient heat that the refractory powder becomes at least partially melted or softened and a cohesive refractory weld mass is progressively built up against that surface. In order to reduce any tendency for the weld mass to include a low-grade refractory phase and thus promote the refractoriness of that weld mass, the fuel powder is present in a proportion of not more than 15% by weight of the total mixture and includes at least two metals selected from aluminum, magnesium, chromium and zirconium, in that at least the major part by weight of the refractory powder consists of one or more of magnesia, alumina and chromic oxide, and in that the molar proportions of silica and calcium oxide present in the refractory powder (if any) satisfy the following expression:molar concentration of SiO.sub.2 in %.ltoreq.0.2+molar concentration of CaO in %.

Abstract: The present invention pertains to a refractory casting slip consisting of a refractory matrix material and a finely divided reactive component, as well as a hydraulic binder and various additives, which can be discharged as a free-flowing mass upon addition of water.