Abstract: An improved compact, white color and pulse operated high pressure sodium vapor arc discharge lamp employing a radiation sensitive getter RF flashed onto the inner surface of the outer lamp envelope has a ceramic radiation shield interposed between the arc tube and getter.

Abstract: Contamination by organic materials is treated by applying an aqueous composition comprising organisms which are useful in degradation of the contaminant, a nutrient for the organisms and a polymer which is soluble in or dispersible in the water and which increases the viscosity of the composition. The composition is useful in the treatment of contaminated liquids and solids and in the protection of solid surfaces against contamination.

Abstract: A refractory-lined high temperature reaction vessel comprises a refractory ring lining constructed of refractory brick, a cooler, and a heat transfer medium disposed between the refractory ring lining and the cooler. The refractory brick comprises magnesia (MgO) and graphite. The heat transfer medium contacts the refractory brick and a cooling surface of the cooler, and is composed of a material that accommodates relative movement between the refractory brick and the cooler. The brick is manufactured such that the graphite has an orientation providing a high thermal conductivity in the lengthwise direction through the brick that is higher than the thermal conductivity in directions perpendicular to the lengthwise direction. The graphite preferably is flake graphite, in the range of about 10 to 20 wt %, and has a size distribution selected to provide maximum brick density.

Abstract: A spray operation method for monolithic refractories, which comprises forcibly sending to an application field by a force feed pump and a force feed piping a self flowable mixed batch prepared by mixing, together with water, a powder composition for monolithic refractories comprising refractory aggregates, a refractory powder and a small amount of a dispersant; injecting into the mixed batch, compressed air and a required amount of a rapid setting agent respectively from a compressed air injection inlet and a rapid setting agent injection inlet provided at a downstream portion or downstream portions of the force feed piping; sending the mixed batch together with the compressed air by a nozzle piping to a spray nozzle attached to the forward end of the nozzle piping; and spraying the mixed batch from the spray nozzle to an application site.

Abstract: The present invention pertains to an electrically conductive, dry, refractory ceramic mass based on a refractory oxidic matrix material containing a source of carbon, such as graphite, carbon black or petroleum coke.

Abstract: Magnesium oxychloride cement bonds are improved by incorporation of graphite. The graphite not only contributes to cooler dry grinding with abrasive tools based on the magnesium oxychloride bond, but unexpectedly also improves heat strength of the bond.

Abstract: Compositions for refractory materials and methods for providing the compositions are described. A synthetic forsterite-rich refractory sand composition includes a mixture. The mixture includes: a) a carbon bridging agent, the carbon bridging agent being present in the mixture in a proportion of from approximately 5 to approximately 15 percent by weight of the mixture; and b) a synthetic forsterite-rich sand, the synthetic forsterite-rich sand being free-flowing, having a MgO:SiO.sub.2 weight ratio of at least approximately 1.2, a specific gravity of approximately 3 g/cm.sup.3, a void volume of less than approximately 50 percent by volume of the synthetic forsterite-rich sand, and a fusion point of at least approximately 1610.degree. C., wherein i) at least approximately 50 percent by weight of the synthetic forsterite-rich sand is forsterite, and ii) from approximately 3 to approximately 27 percent by weight of the synthetic forsterite-rich sand is maghemite.

Abstract: A process is described for the production of alumina/zirconia materials which uses cheap scrap alumina/zirconia/silica material as feedstock along with a reducing agent to lower the final silica content to an acceptable level.

Abstract: Chrome-free bricks which exhibit excellent resistance to corrosion, penetration, and thermal spalling. The bricks are mainly made from a magnesia material and/or a magnesia-alumina spinel material and comprise 1 to 10 wt % titania and 1 to 15 wt % alumina. They may contain 0.5 to 10 wt % iron oxide. Further, they may contain at least one material of the group consisting of 1 to 10 wt % metal powder, 1 to 20 wt % carbon and 1 to 20 wt % one of oxide materials except for iron oxide.

Abstract: Magnesium oxychloride cement bonds are improved by incorporation of graphite. The graphite not only contributes to cooler dry grinding with abrasive tools based on the magnesium oxychloride bond, but unexpectedly also improves heat strength of the bond.

Abstract: A magnesite-carbon refractory mix for forming refractory shapes containing magnesite, graphite, and a fine particle size metallic additive consisting essentially of a magnesium-aluminum alloy co-milled with magnesite and refractory shapes and refractory linings made therefrom.

Abstract: Ceramic precursor materials bound together by a product of a condensation reaction between a first reactant that has at least one reactive hydroxyl moiety, such as a carbohydrate, and a second reactant that has at least one reactive nitrogen-containing moiety, such as melamine, and dried or dried and calcined, form porous aggregates that resist crushing or disintegration during processing through various reactor apparatus.

Abstract: A composition comprising leonardite, clay, lime, and an inorganic salt mixture and a process for controlling air quality comprising contacting an air stream with the composition are provided wherein the composition supports microbial growth. The inorganic salt mixture comprises a nitrogen source and a phosphorus source. The air stream generally contains at least one volatile organic compound.

Abstract: A dry vibratable substantially alkali free refractory composition is disclosed for use as a disposable liner wherein the combination of a powdered metal utilized as a high temperature binder and an organic material utilized as a low temperature binder obviates the use of alkali oxides which previously caused degradation of the permanent refractory liner materials upon which the disposable lining was placed. Low density materials such as expanded inorganic materials can be added to the disclosed compositions to decrease the density. The invention also relates to a method of providing a disposable lining in a vessel having a permanent refractory lining, and to the resulting vessel thereof.

Abstract: Carbon-containing carbon bonded refractory mixes and products made therefrom in which the refractory is a magnesite or high alumina aggregate and containing a silica-free elemental boron containing B-Mg-O alloy powder containing at least 95% B-Mg-O. and shapes made therefrom. The invention also involves the method of increasing the lining life of a metallurgical vessel utilizing unburned brick made from the above-noted mixes.

Abstract: The present invention discloses an alkali oxide free low density refractory material especially adapted for use as a disposable liner material for molten metal containing vessels. This material includes about 0.1 to about 2 weight percent of a stiffening agent, about 0.1 to about 2 weight percent of a set retarding agent, about 0.1 to 6 weight percent of density reducing materials, about 0.1 to about 5 weight percent of a plasticizer, up to about 2 weight percent of a secondary binder, and the balance of a refractory aggregate which is preferably MgO. The stiffening agent and set retarding agent are used in substantially the same amounts to provide the disclosed refractory material with increased resistance to slumping while, at the same time, allowing spraying apparatus residence times of up to 30-40 minutes without clogging. The composition includes less than about 0.

Abstract: The invention relates to refractory materials which comprise:(A) grains of at least one refractory material whose melting point and thermal decomposition temperature are higher than 1700.degree. C.;(B) a binding matrix which binds these grains together and predominantly consists of aluminum nitride AlN of hexagonal structure and/or of at least one of the polytypes of AlN; and(C) hexagonal boron nitride particles and/or crystalline graphite flakes dispersed in the binding matrix.Applications in iron and steel metallurgy, in particular as plates in a slide closure device.

Abstract: A mix for forming a magnesite-carbon refractory shape comprising from about 70 to 97 wt. % deadburned magnesite and about 3 to 30 wt. % flake graphite, and for each 100 wt. % of said magnesite and graphite, from about 1.5 to 6 wt. % of a carbon-containing bonding agent; said graphite containing from 90 to 99 wt. % carbon and having a lime/silica ratio greater than 0.2 in its ash and said magnesite containing greater than 95 wt. % magnesia, and the resultant magnesite-carbon refractory shapes and liners for metal processing equipment made from such shapes and the method of increasing the life of liners for such equipment.

Abstract: The invention concerns a fired magnesia-carbon shape having a combination of properties making it especially suitable for slide gate plates, inserts for such plates and for pouring nozzles useful in casting aggressive steels. The fired refractory shape is formed from a batch consisting essentially of, by weight percent,2 to 8 finely divided graphite (natural or synthetic);3 to 8 aluminum metal powder;1 to 5 of finely divided silica and/or a silicon yielding powder;an effective amount of carbon bond forming resins;and the balance coarse and fine magnesia grains.The magnesia grains should contain less than about 0.02 weight percent boron oxide. After firing, the shape is characterized by a carbon bonding system including a spinel (magnesia-alumina) phase plus aluminum carbide bonding the magnesia-carbon matrix. The refractory shape is preferably carbon impregnated after firing to further enhance its properties.

Abstract: Hydrophilic graphite-base powder is provided wherein hydrophilic small particles of such as silicon carbide or silica are mixed with a graphite powder and the small particles are attached to each surface of the graphite particles by performing a mechanical impact treatment in a high-speed gas flow. By combining the graphite-base powders with refractory compound powders of such as magnesia or alumina to be a powder mixture for monolithic refractories containing graphite, a formed body of the powder mixture having a large bulk density can be provided and a service life thereof is comparable to that of a shaped refractory, and labor and energy necessary for the production process and the operation are saved.

Abstract: Calcium aluminum magnesium phosphate ceramic hard tiles and processes for them are described. The tiles have a density in excess of about 110 pounds per cubic foot, a curl value less than about 20 mils and a flexural strength of at least about 2500 pounds per square inch. To prepare the hard tiles 100 parts (by wt.) of an aluminum phosphate-phosphoric acid solution is mixed with at least 5 parts magnesium oxide and 50-110 parts wollastonite. If the acid has more than 15% by weight water, then mica or vermiculite is added.

Abstract: A monolithic refractory with improved resistance to molten aluminum and a method of imparting the resistance by adding 0.2 to 1 wt.% polyvinyl chloride powder to the base mix.

Abstract: Ceramic matrix composite articles comprising a matrix phase composed of a silicate glass or glass-ceramic and a matrix reinforcement material disposed within the matrix comprising carbon (e.g., graphite) fibers are described, wherein the fibers are provided with a protective boron nitride surface coating. The mechanical properties of the composites at high temperatures are substantially improved.

Abstract: This invention relates to a process for the preparation of a crystalline compound having an empirical formula LaCr.sub.x A.sub.1-x O.sub.4 .multidot.yH.sub.2 O where A is a metal selected from the group consisting of Mg, Sr, Ca and Ba, x ranges from 0.99 to about 0.7 and y ranges from 0 to 0.15. The process comprises adding a solution of the appropriate metal salts to a solution of ammonium hydroxide thereby precipitating a hydroxide gel intermediate, which is dried and calcined in air to yield the resultant crystalline compound which has a huttonite structure. Additionally, this invention relates to a process for the preparation of a ceramic powder having the empirical formula LaCr.sub.x A.sub.1-x O.sub.3, where A is a metal selected from the group consisting of Mg, Sr, Ca and Ba and x ranges from 0.99 to about 0.7. Finally, a ceramic composition having the empirical formula LaCr.sub.x S.sub.1-x O.sub.4 .multidot.yH.sub.2 O having a huttonite structure is also disclosed.

Abstract: Disclosed herein are a refractory repairing material for repairing a brick comprising a mixture of 70 to 80 wt % of alumina having not more than 1 mm of grain size, which comprises 25 to 30 wt % of the above amount with a grain size not passing through a 325 mesh and 45 to 50 wt % of the above amount with a grain size passing through a 325 mesh; 1 to 7 wt % of carbonaceous material having a grain size passing through a 60 mesh; 1 to 5 wt % of magnesia having a grain size passing through a 325 mesh; and 10 to 25 wt % of aluminum phosphate, and a method of repairing a plate-like brick.

Abstract: A process of forming a coherent refractory mass on a surface comprises projecting against that surface, together with oxygen, a mixture of refractory particles and fuel which reacts in an exothermic manner with the projected oxygen to release sufficient heat to melt at least the surfaces of the refractory particles and thus form the refractory mass. The projected mixture contains, as fuel, finely divided particles of at least one element which is oxidizable to form a refractory oxide and it also contains carbonaceous particles which are of such a size or composition that carbon particles become occluded in the formed refractory mass. The mixture may contain, as said fuel, finely divided particles having a mean grain size of less than 50 .mu.m of silicon, aluminum and/or magnesium. The carbonaceous particles may comprise a carbonaceous core which is covered by a mantle inhibiting oxidation of the core.

Abstract: Disclosed herein are a refractory repairing material for repairing a brick comprising a mixture of 70 to 80 wt % of alumina having not more than 1 mm of grain size, which comprises 25 to 30 wt % of the above amount with a grain size not passing through a 325 mesh and 45 to 50 wt % of the above amount with a grain size passing through a 325 mesh; 1 to 7 wt % of carbonaceous material having a grain size passing through a 60 mesh; 1 to 5 wt % of magnesia having a grain size passing through a 325 mesh; and 10 to 25 wt % of aluminum phosphate, and a method of repairing a plate-like brick.

Abstract: A mix for forming a carbon-bonded refractory comprising from about 8 to 30 wt. % of a high purity carbon, about 0.1 to 1 wt. % of aluminum metal, magnesium metal, or a mixture thereof, and the balance a high purity magnesite, and for each 100 wt. % of said magnesite, carbon, and metal, a carbonaceous bonding agent in an amount sufficient to bond the mix; said carbon containing at least about 98% carbon and said magnesite containing at least about 98% MgO, and containing less than about 0.03% boron oxide, less than about 0.3% silica, and having a CaO/SiO.sub.2 weight ratio above about 2, and the resultant carbon-bonded refractory shapes and liners for metal processing equipment, especially BOF, made from such shapes and the method of increasing the life of liners for such equipment.

Abstract: In processes of forming a refractory mass on a surface, a mixture of refractory particles and oxidizable particles which react exothermically with oxygen to generate sufficient heat to soften or melt at least the surfaces of the refractory particles are sprayed against that surface to bring about formation of said refractory mass. To promote the reliable and consistent formation of a durable refractory mass, the granulometry of the particles which are sprayed in the mixture is such that the 80% and 20% grain sizes of the refractory particles (that is, the screen mesh sizes G.sub.80 and G.sub.20 through which respectively 80% and 20% by weight of the particles will pass) have a mean greater than the mean of the 80% and 20% grain sizes of the oxidizable particles and the size range spread factor f(G) of the refractory particles is at least 1.

Abstract: Improved high temperature resistant molding materials containing customary filler materials and additives and a carbon forming bonding agent which is a phenol novolac with a molar ratio of phenol to formaldehyde of 1 to 0.2 to 1 to 0.35 of high quality and free of solvents useful as refractory products, carbon materials, abrasive wheels, friction lining and the like.

Abstract: A mix for forming a carbon-bonded refractory shape comprising from about 70 to 92 wt. % of a high purity magnesite and about 8 to 30 wt. % of a high purity graphite, and for each 100 wt. % of said magnesite and graphite, from about 1.5 to 6 wt. % of a carbon-containing bonding agent; said graphite containing at least about 98% carbon and having at least about 75% by weight -65 mesh or finer particles and said magnesite containing at least about 98% MgO, and containing less than about 0.03% boron oxide, less than about 0.3% silica, and having a CaO/SiO.sub.2 weight ratio above about 2, and the resultant carbon-bonded refractory shape and liner for basic oxygen furnaces made from such shapes and the method of increasing the life of liners for basic oxygen furnaces.

Abstract: A high-temperature resistant blast pipe is primarily intended for delivering gas, such as oxygen, and, when appropriate, solid material to metallurgical processes, and incorporates a layer of refractory material comprising a refractory mixture of solid particles and an alkali-silicate based binder.The blast pipe is characterized in particular in that the major constituent of the binder is of the type polymerized alkali silicate.

Abstract: In the manufacture of refractory bricks containing CaO, a mixture is formed of a refractory composition of a material containing CaO and a binder composition, and bricks are moulded from the mixture. To avoid hydration of the CaO and avoid softening of the bricks on heating up, the material containing CaO is selected from burned lime, burned dolomite and mixtures and the binder composition is present in an amount in the range 1 to 10% by weight based on the weight of the mixture and consists mainly of a thermosetting novolak type phenol resin composition and an anhydrous solvent consisting of at least one organic solvent present in an amount of less than 40% by weight based on the weight of the binder. The solvent composition is chosen to be of a chemical nature such that, at least during mixing of the refractory composition and the binder composition, it substantially does not react with the CaO.

Abstract: The invention concerns a coating for providing protection from corrosion and oxidation in the hot state, which coating is intended for the carrier bars of prebaked anodes and the emergent, or exposed, carbonaceous part of said anodes for Hall-Heroult electrolysis tanks, which elements are formed of a composition of carbonaceous aggregate selected from coke, graphite, semi-graphite and electrode scrap, together with calcium aluminate cement having an alumina content which is at least equal to 70% and a total amount of troublesome impurities (SiO.sub.2, Fe.sub.2 O.sub.3, TiO.sub.2, K.sub.2 O, Cr.sub.2 O.sub.3 and Mn.sub.2 O.sub.3) of less than 5% and preferably less than 2%. The protective coating may further comprise an addition of alumina powder in a proportion which can be up to 50% of the weight of the aggregate and an addition of 0.01% to 5% of metal powder such as passivated aluminium powder of a grain size of less than 0.1 mm. The coating may be used in the form of paste or be applied by spray gun.

Abstract: A refractory composition which is suitable for forming a sliding gate to be used at the bottom of a ladle or tundish is provided. The refractory composition comprises 10 to 30 parts by weight of an alumina-magnesia spinel material containing 40 to 70% by weight of Al.sub.2 O.sub.3, 25 to 60% by weight of MgO and 10% or less of impurities, and 70 to 90 parts by weight of a magnesia material containing at least 90% by weight of MgO, wherein the composition contains 10 to 25% by weight of Al.sub.2 O.sub.3 and 75 to 90% by weight of MgO. 1 to 10 parts by weight of Al.sub.2 O.sub.3 material may be further added together with the alumina-magnesia spinel material and the magnesia material, to form the refractory composition.

Abstract: Coal gasifiers for the production of reducing gas are protected--at least in parts--by a refractory lining of unburned, carbonaceous magnesia bricks having a carbon content of 5 to 30 percent by weight. The component of these magnesia bricks consisting of sinter and/or fused magnesia suitably has a Fe.sub.2 O.sub.3 content below 6 percent by weight, preferably below 1.5 percent by weight, and a SiO.sub.2 content below 3 percent by weight, preferably below 1 percent by weight.

Abstract: A method for the manufacture of a magnesia-carbon brick comprising the steps of:a. preparing a mixture comprising:1. burned magnesite2. carbon3. binder solution comprising3.1 precondensed novolak resin3.2 solvent for the novolak resin4. a hardener for the resinb. pressing a brick from the said mixture.

Abstract: A method for producing a porous magnesia clinker by admixing a magnesia material having a grain size of less than 0.1 mm with from 10 to 60 percent by weight of the mixture of fluid oil coke having a grain size of 1 mm or less, calcining the resulting mixture at a temperature of from 900.degree. to 1600.degree. C. for a time sufficient to burn off the coke and thereby to form pores in the magnesia material, and firing the resulting product at a temperature of from 1600.degree. C. to 2030.degree. C. to produce porous magnesia clinker.

Abstract: The present invention provides a carbon-containing refractory composition characterized by containing 0.1-10 parts by weight of silicon hexaboride in 100 parts by weight of refractory material comprising 3-95 parts by weight of carbonaceous material such as graphite and 97-5 parts by weight of refractory aggregate.In the carbon-containing refractory composition of the present invention, silicon hexaboride is oxidized producing boron oxide on the surface of the refractory at a high temperature during operation, and the surface of the refractory is covered by the formation of a highly viscous molten liquid like kotoite (3 MgO.B.sub.2 O.sub.3), for example, which is formed from the components of the refractory, such as MgO, for example, thus particles of carbonaceous material such as graphite can be protected from oxidation.

Abstract: A periclase refractory composition comprising magnesium oxide granules, carbon granules and a carbonaceous binding material capable of undergoing pyrolytic decomposition. Added to the periclase refractory composition is at least one oxyhydrocarbon compound selected from the group consisting of (a) acyclic carboxylic acids, (b) oxidized polyolefin waxes, (c) poly(alkylene oxides) and ethers thereof, (d) olefin copolymers, (e) polyvinyl alcohol, and (f) furan polymers.

Abstract: An elemental carbon-containing refractory composition having superior erosion and oxidation resistance due to the addition of prescribed amounts of boron carbide.

Abstract: Refractory brick comprising a refractory aggregate, carbonaceous material and powdered metal bonded with a combination of liquid thermosetting resin and impregnating pitch.

Abstract: A forsterite-carbon refractory containing forsterite material, carbonaceous material, silicon carbide and magnesia refractory material.

Abstract: Carbon in the form of graphite is commonly used in refractories for metallurgical purposes because of its ability to increase resistance to corrosion. However, if the graphite in the refractory becomes oxidized, it greatly loses this ability. For this reason, it is very important for a refractory to have good resistance to oxidation, but there are at present no refractories fully satisfactory from the standpoints of resistance to oxidation and hot strength.The present invention is a carbon-containing refractory having excellent resistance to oxidation and hot strength. These favorable properties are obtained by the addition in the refractory of both boron carbide and metal powder, the powder comprising at least one metal selected from Al, Si, Fe, and Ni.

Abstract: A more pressable composition for making graphitic refractory brick from oxide aggregate with a carbon bond is obtained when the refractory oxide aggregate is substantially all coarser than 0.15 mm (+100 mesh), preferably coarser than 0.2 mm (+65 mesh), and most preferably coarser than 0.4 mm (+35 mesh), and the matrix is entirely carbonaceous material, such as graphite, particularly flake graphite, resin, particularly a phenol formaldehyde resin, together with such other carbonaceous materials as carbon black, calcined coke, anthracite, and the like.

Abstract: The invention relates to carbon-bonded magnesia carbon bricks for use in converters, ladles, ladle refinery, mixing cars, mixing furnaces, etc., and the method for obtaining such carbon-bonded magnesia carbon bricks having high properties in respect of resistance to thermal and structural spalling, slag resistance, thermal strength, shock resistance, etc. thereby enabling to conform to the gradually intensified operational conditions of said converters and the like by means of 60-97 weight % sintered magnesia clinker of bulk specific gravity above 3.40, 3-40 weight % carbonaceous material and a carbon-bonding formative agent.

Abstract: Carbon bonded refractory brick containing 1 to 6% by weight liquid thermosetting resin binder consisting of polyhydroxydiphenyl resin and a curing agent and the balance being refractory aggregate.

Abstract: A refractory shape having improved resistance to erosion in metal melting vessels and high modulus of rupture, comprising an anhydrous refractory material, an anhydrous organic binder, from 0.3% to about 30% finely divided elemental carbon having a particle size ranging from 0.01 to about 1 mm, and from 0.3% to about 10% particulate elemental magnesium, based on the weight of the refractory shape. Addition of both elemental carbon and elemental magnesium results in a synergistic improvement in slag erosion resistance.

Abstract: A refractory brick or mass is comprised of 60 to 97% of sinter magnesia, an amount of a carbon-containing substance producing a residual content of 2 to 30% of carbon in an end product after carbonization, as determined by ASTM norm C 831-76, and 1 to 20%, calculated as chromium metal, of metallic chromium or a metallic chromium compound, which is primarily fine-grained and at least 80% thereof, based on the chromium metal content, has a grain size of less than 1 mm, all percentages being by weight.

Abstract: A tundish veneer composition comprising about 45-80 percent by weight of MgO, about 1-7 percent by weight of a refractory clay filler, about 1-15 percent by weight of a refractory glass wool fiber, about 3-10 percent of aqueous colloidal silica binder, and optionally, up to about 15 percent by weight of graphite, a foaming agent, or a dispersing agent.