Abstract: Ceramic bodies comprised mainly of zircon and wollastonite, with zircon being the dominant crystalline phase, show improved resistance to alkaline conditions at elevated temperatures than conventional bodies and excellent thermal stability.

Abstract: Hydrophilizing compositions based on aqueous colloidal silica and zirconyl salts and a process for rendering surfaces hydrophilic with such compositions are provided.

Abstract: A process for producing a zirconia beating opacifier is disclosed. The process comprising the steps of: (I) heat treatment of a zirconia bearing material comprising heating the zirconia bearing material in the presence of an additive to form a heat modified product having one or more phases which, when incorporated in a glaze and the glaze fired, exhibit opacifying characteristics; and (ii) cooling the heat modified product to produce a product which can be used for imparting opacity.

Abstract: Gels based on a network of oxygen-bridged metal and/or semi-metal atoms and produced using a hydrolytic sol-gel process are often not homogeneous. Known non-hydrolytic sol-gel processes give rise to gels containing halogen.A novel non-hydrolytic sol-gel process has been found which gives rise to halogen-free and homogeneous gels and to xerogels obtainable therefrom.In this process, one or more compounds (I) from the series of metal or semi-metal alkoxides, oxoalkoxides, amides or oxoamides are condensed, with elimination of carboxylic acid esters or carboxylic acid amides, until gelation occurs with one or more compounds (II) from the series of metal or semi-metal carboxylates or oxocarboxylates in an anhydrous organic solvent containing no hydroxyl groups.Preferred gels and xerogels contain in the network metal or semi-metal atoms from main group and subgroup III to V and from the rare-earth elements.

Abstract: A refractory powder includes a filler, a binder, and a metal powder. This provides improved heat transfer in the refractory material during heating, and reduces the problem of explosive cracking and spalling so the refractory material can be burned out at substantially constant temperature, thereby saving considerable amounts of time and energy.

Abstract: A method of atomic scale fixation and immobilization of plutonium to provide a durable waste product. Plutonium is provided in the form of either PuO.sub.2 or Pu(NO.sub.3).sub.4 and is mixed with and SiO.sub.2. The resulting mixture is cold pressed and then heated under pressure to form (Zr,Pu)SiO.sub.4 as the waste product.

Abstract: Three families of ceramic compositions having the given formula: .phi..sub.1+X Zr.sub.4 P.sub.6-2X Si.sub.2X O.sub.24, .phi..sub.1+X Zr.sub.4-2X Y.sub.2X P.sub.6 O.sub.24 and .phi..sub.1+X Zr.sub.4-X Y.sub.X P.sub.6-2X Si.sub.X O.sub.24 wherein .phi. is either Strontium or Barium and X has a value from about 0.2 to about 0.8 have been disclosed. Ceramics formed from these compositions exhibit very low, generally near neutral, thermal expansion over a wide range of elevated temperatures.

Abstract: A zirconium silicate brick and a method for producing same, the brick having a starting powder used to form the brick, the starting powder having minimal amounts of contaminants in the amount of not more than about 0.3 percent Al.sub.2 O.sub.3, not more than about 0.2 percent TiO.sub.2, and not more than about 0.1 percent Fe.sub.2 O.sub.3, each, based on the weight of the starting powder, to which a phosphorous compound in the amount of about 0.1 percent to about 5 percent based on the weight of the starting powder is added prior to making the brick for producing a brick with improved corrosion resistance for use in glass melting facilities with boron silicate glasses, and having improved decomposition behavior at higher glass melting temperatures.

Abstract: A fired, porous, zircon refractory body consisting essentially of zircon and having a sodium ion content, as an impurity, of less than 30 ppm. A furnace for making fused silica constructed with a crown and cup of such zircon refractory, and a method of making fused silica using such furnace.

Abstract: A thermal spray powder feed coating composition composed of stabilized zirconia mixed with zircon and a selected oxide, such as yttria, to form a refractory oxide coating ideally suited for hearth rolls for annealing steel Process for producing the coating and the coated article so produced is also disclosed.

Abstract: A heat resistive phosphate sintered body including a solid solution of R.sub.y Zr.sub.4 Si.sub.x P.sub.6-x O.sub.24 in which O.ltoreq.x.ltoreq.2, 2/3.ltoreq.y.ltoreq.2, R is a combination of one or more of cations having 2-3 valences, and x and y meet an electrically neutral condition, wherein a thermal expansion hysteresis loss is not more than 0.3%, and a dimensional change after a heat cycling in which heating and cooling are repeated between 100.degree. C. and 1,200.degree. C. at 100 times is not more than 1%. A process for producing such a heat resistive phosphate is also disclosed. The process includes the steps of preparing a batch mixture, as a starting material, of (ZrO).sub.2 P.sub.2 O.sub.7, ZrP.sub.2 O.sub.7, RO and/or a phosphate of R in which R is a combination of one or more of cations having two or three valences, and if necessary further SiO.sub.2, calcining, milling and shaping the thus prepared mixture, and firing the thus shaped body, wherein a calcining temperature is not less than 1,400.

Abstract: A method for preparing zircon powder, which comprises mixing (1) silica sol and (2) an aqueous zirconium oxychloride solution having a concentration which would be from 0.1 to 2 mols/l after mixed with the silica sol, in a SiO.sub.2 /ZrO.sub.2 molar ratio of from 0.95 to 1.10, heating the mixture to hydrolyze the zirconium oxychloride, followed by dehydration treatment to obtain a powder, heating the powder from room temperature to a calcination temperature over a period of from 0.7 to 30 hours and calcining the powder at a temperature of from 1,200.degree. to 1,400.degree. C. for a period of time satisfying the relation of:t.gtoreq.116-0.08Twhere t is the calcination time (hr) and T is the calcination temperature (.degree.C.), or heating the powder from room temperature to a calcination temperature over a period of from 0.8 to 70 hours and calcining the powder at a temperature higher than 1,400.degree. C. and not higher than 1,700.degree. C. for a period of time satisfying the relation of:t.gtoreq.18-0.

Abstract: A method for the synthesis of mixed metal oxide crystalline powders comprises the steps of preparing a raw material mixture containing at least two different metal cations; adding a template material to the mixture and blending it therewith; initiating formation of a mixed metal oxide by calcination of the mixture and the template material, whereby particles of the mixed metal oxides are formed; and thereafter recovering the mixed metal oxide particles. Mixed metal oxide crystalline powders comprise a template material; and metal oxides which form pigment classes of material containing the template material, the pigment classes being selected from the group consisting of borate, garnet, olivine, phenacite, phosphate, priderite, pyrochlore, sphene, spinel and zircon, as well as perovskite crystal classes of material containing the template, all of which have a uniform particle morphology and particle size ranging between about 0.2 to 100.mu. with minimal comminution.

Abstract: A heat resistive phosphate-zircon composite body including a main crystalline phase and a secondary crystalline phase, the main crystalline phase being a solid-solved phase of R.sub.y Zr.sub.4 Si.sub.x P.sub.6-x O.sub.24 in which 0<x<2, 2/3<y<2, and R includes of one or more kinds of bivalent or trivalent cations (provided that x and y satisfy electrical neutrality), and the secondary crystalline phase being zircon. A process for producing a heat resistive phosphate-zircon composite body is also disclosed. The process includes the steps of measuring and mixing given amounts of ZrP.sub.2 O.sub.7, (ZrO).sub.2 P.sub.2 O.sub.7, RO and/or a phosphate of R, SiO.sub.2 and a zircon powder, shaping the mixture and firing the shaped body, wherein the given amounts of ZrP.sub.2 O.sub.7, (ZrO).sub.2 P.sub.2 O.sub.7, RO and/or the phosphate of R, and SiO.sub.2 are measured such that the composite body may include a main crystalline phase composed of a solid-solved phase of R.sub.y Zr.sub.4 Si.sub.x P.sub.

Abstract: The present invention relates to ZrO.sub.2 - and SiO.sub.2 -based ceramic fibers in which the weight ratio between SiO.sub.2 and ZrO.sub.2 is comprised between 99 and 0.7. The tetragonal ZrO.sub.2 phase is stable at temperatures comprised between 0.degree. and 1500.degree. C. The process comprises the preparation of: a solution of Zr(OR.sup.1).sub.4, where R.sup.1 is an alkyl or aryl, Si(OR.sup.2).sub.4, where R.sup.2 is alkyl or aryl, an organic solvent and an acid. Vapor-phase water is bubbled in said solution, then the obtained solution is drawn and the fibers thus obtained are heated to obtain the crystallization of ZrO.sub.2 and SiO.sub.2.

Abstract: Improved inorganic ceramic papers comprising heterogeneous grades of ceramic fibers, namely small, high surface area fibers and at least one larger, lower surface area ceramic fiber are bonded into a matrix with the aid of an inorganic binder system having at least one metal oxide with an average particle size below 200 nm. Multiple different grades of inorganic ceramic fibers and small particle size inorganic binders impart good tensile strength and flexibility characteristics in the same sheet.

Abstract: Dense zircon refractories having improved thermal shock damage resistance for use in glass melt or high alkali vapor contact applications comprise, and, consist essentially of, about fifty percent by weight or more ZrSiO.sub.4, at least about one percent zirconia in particle form distributed substantially uniformly throughout the composition of the refractory, and optionally, a zircon grain growth enhancing composition, preferably TiO.sub.2.

Abstract: A refractory for casting a basic substance comprises 100 parts by weight of a refractory aggregate having as main ingredients 3 to 40% by weight of zircon and 97 to 60% by weight of magnesia and a suitable amount of a binding agent. Another refractory for casting a basic substance comprises 100 parts by weight of a refractory aggregate having as main ingredients 3 to 40% by weight of zircon and 97 to 60% by weight of magnesia, not more than 7 parts by weight of metallic fibers, and a suitable amount of a binding agent. The refractories for casting a basic substance are used for ladles, tundishes, vacuum degasing furnaces, mixers, and the like.

Abstract: A method of providing a ceramic coating on a substrate, for example of aluminum, where a slurry of a zirconium compound such as zirconia and a silicate such as potassium silicate is coated on a substrate and cured at a temperature not exceeding 500.degree. F.

Abstract: A preparation method for zircon powder, which comprises heating a feed powder mixture comprising:(1) silica and zirconia obtained by subjecting a liquid having a pH of not higher than 8 and containing silica and zirconia in a SiO.sub.2 /ZrO.sub.2 molar ratio of substantially 1/1, to liquid-removing treatment, and(2) zircon in an amount of at least 0.1% by weight based on the total amount of said silica and zirconia,at a heating rate of not higher than 5.degree. C./min from 1,200.degree. C. to a calcination temperature, and maintaining it at a calcination temperature of from 1,300.degree. to 1,700.degree. C. for from 1.0 to 24 hours.

Abstract: A high-temperature protective coating comprising a ceramic material, in particular for structural components of super-alloys, characterized in that at least one oxide of a metal of subcolumn 4 of the periodic table of elements is stabilized with at least one further oxide of a metal and is enveloped in a corrosion-resistant manner, at least in some regions, by at least one ceramic material.

Abstract: Fused AZS grain refractory compositions suitable for making ceramically or chemically bonded refractory articles, and the articles so made, are disclosed. The refractory compositions consist essentially of (a) 40-85 wt. % fused AZS grain, and (b) 15-50 wt. % of at least one constituent selected from the group consisting of (i) 10-20 wt. % reactive alumina and (ii) 0-45 wt. % chromic oxide.

Abstract: A settable liquid system for refractories comprises a gelable alkoxide such as ethyl silicate, water to hydrolyze the alkoxide and a mutual solvent for the alkoxide water and any catalyst. The system further includes a solvent for the alkoxide only.

Abstract: Solid, transparent, non-vitreous, microspheres (zirconia-silica) are formed by extractive gelation (extracting carboxylic acid away from zirconyl carboxylate) of a sol in liquid medium such as hot peanut oil. Zirconyl carboxylate precursor sol is prepared and added in droplet form to the liquid extractant (peanut oil) at an elevated temperature at which a carboxylic acid is liberated from the zirconyl carboxylate. The droplets remain in the extractant for sufficient time to form stable gel spheroids which are separated from the extractant and fired to convert them to durable spheroids useful as lens elements in retroreflective sheeting.

Abstract: A novel solid solution has a composition of R.sub.y Zr.sub.4 Si.sub.x P.sub.6-x O.sub.24 (R is at least one forming bivalent or trivalent element 0.ltoreq.x.ltoreq.2, 2/3.ltoreq.y.ltoreq.2). Furthermore, a heat-resistant sintered body and heat-resistant phosphate based compound sintered body comprises the above solid solution and has excellent heat resistance and high temperature stability. And also, a method of producing such sintered bodies is disclosed.

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: A refractory article and a process for making the same are provided. The article is derived from dissociated zircon and zirconia (99:1 to 80:20, weight basis). These components are formed into a slip, which can be conventionally processed to provide a sintered article. The resulting article can be subsequently heat treated to react any resulting glass phase with the zirconia present; further, the heat treated article can be subsequently redensified. These refractories are well-suited for such applications as tundish nozzle inserts and sliding gate valves.

Abstract: Heat resisting low expansion zirconyl phosphate-zircon composite bodies are disclosed, which contain zirconyl phosphate and zircon as a main crystalline phase and a secondary crystalline phase, respectively. The heat resisting low expansion zirconyl phosphate-zircon composite bodies have a coefficient of thermal expansion in a temperature range from room temperature to 1,400.degree. C. being not more than 30.times.10-7/.degree. C. and a melting point being not less than 1,600.degree. C. The composite bodies have a chemical composition essentially consisting of 58.2 to 65.4% by weight of ZrO.sub.2, 17.4 to 37.1% by weight of P.sub.2 O.sub.5, and 1.5 to 19.0% by weight of SiO.sub.2. The heat resisting low expansion zirconyl phosphate-zircon composite bodies optionally contain MgO and Al.sub.2 O.sub.3 in a total amount of not more than 2.5% by weight or 0.1 to 4% by weight of Nb.sub.2 O.sub.5. A process for producing such zirconyl phosphate-zircon composite bodies is also disclosed.

Abstract: A ceramic material which comprises a composite of zirconia and O'-sialon or silicon oxynitride.The ceramic material may comprise a dispersion of zirconia in an O'-sialon matrix and such a dispersion is obtained when the amount of zirconia is from 5 to 30 volume percent, preferably 15 to 25 volume percent, based on the total volume of the composition.

Abstract: The present invention relates to a shaped, molded refractory and insulating product derived from the chemical bonding of muscovite, phlogopite or mixtures thereof with an acid aluminum phosphate having a ratio of Al:P of from 0.286 to 0.666 to which may be added an inert filler, a monofilament or oriented monofibers or woven fibers and which may have a metal cladding adhering to at least one surface of the shaped product.

Abstract: Refractory material based on grog and hydraulic or chemical binder. The refractory material contains a substantially evenly distributed content of a heat-resistant fiber reinforcement and cutting-material in individual pieces; the use of such refractory material as a constructional material in units for storing valuables, such as bank vaults, safes and the like; and a unit for storing valuables including such refractory material.

Abstract: Solid, transparent, non-vitreous, zirconia and zirconia-silica ceramic microspheres, useful as lens elements in retroreflective pavement markings. The microspheres are characterized by:(a) containing at least one additive metal oxide selected from alumina, magnesia, yttria and mixtures thereof;(b) an index of refraction greater than 1.6; and(c) being virtually free of cracks.These microspheres are formed by a sol-gel technique of extractive gelation (extracting carboxylic acid away from zirconyl carboxylate) of a sol in liquid medium such as hot peanut oil. The microspheres of this ceramic composition have been made with relatively large diameters, (e.g. 200-1000 micrometers) making them quite useful as lens elements in pavement marking sheet materials.

Abstract: This invention is directed to the production of ceramic alloys consisting essentially of ZrO.sub.2, titania, and yttria or rare earth oxides such as gadolinia, ytterbia, neodymia, and ceria. Mole % concentration values as low as 0.25 mole % for yttria have been found to provide a hard and tough ceramic alloy in the presence of the titania-zirconia body. These compositions have been found to produce effective hard and tough ceramic bodies when mixed with refractory fibers and/or whiskers and hard refractory ceramics.

Abstract: A low thermal expansion potassium zirconium phosphate is formulated using a metal oxide as a densifier. A mixture of these powders is sintered and quenched.

Abstract: A low-temperature sinterable ceramic composition comprising 1 to 20% by weight of Al.sub.2 O.sub.3, 15 to 50% by weight of SiO.sub.2, 0 to 5% by weight of MgO, 3 to 18% by weight of CaO, 0 to 5% by weight of TiO.sub.2, 1 to 8% by weight of B.sub.2 O.sub.3, 0 to 2% by weight of Li.sub.2 O, 20 to 80% by weight of at least one of zircon, mullite and spinnel, and 1 to 12% by weight of a fluoride selected from CaF.sub.2, MgF.sub.2, LiF, AlF.sub.3, MnF.sub.2, BaF.sub.2 and SrF.sub.2.

Abstract: In the production of low-thermal-expansive zirconyl phosphate ceramic, whose chemical formula is (ZrO).sub.2.P.sub.2 O.sub.7 and whose chemical composition is 2ZrO.sub.2.P.sub.2 O.sub.5 by sintering of the fine-powder compact, three kinds of reaction aids are employed. They are a densifying aid, a grain-growth-suppressing aid and a solid-solution-forming aid. The densifying aid is always employed, the grain-growth-suppressing aid is employed for producing a more thermal-resistant ceramic for high temperature use and the solid-solution-forming aid is employed for producing a more low-thermal-expansive ceramic.

Abstract: A low expansion ceramic composition is represented by the formula Ca.sub.0.5 Ti.sub.2 P.sub.3 O.sub.12 in which up to 100 percent of the Ca is replaced by one or more of the other alkaline earth metals and alkali metals, the alkali metals being selected from the group consisting of Na, Li, K and combinations thereof and substituted in the ratio of two units of alkali metal for each unit of Ca replaced. Up to 100 percent of the Ti is replaced by one or more members selected from the group consisting of Zr, Sn, Nb, Ta and Cr. For each unit of Cr replacement an approximately equal unit of alkali metal is added. For each unit of Nb and/or Ta replacement an approximately equal unit of Na and/or K replaces a unit of Ca. Up to 100 percent of the P may be replaced by Si and/or S. The total of the amounts of Ca, other alkaline earth metals, Li, K, Ti, Sn, Nb, Ta and Cr is greater then zero. Preferably up to 100 percent of the Ca is replaced by Na, and up to 100 percent of the Ti is replaced by Zr or NaCr.

Abstract: A refractory material consists of a zircon matrix with zirconia particles dispersed in it. The zirconia particles comprise from 5 to 30 percent (by weight) of the material. A method of making this material involves milling zircon sand particles and zirconia particles until they have a respective predetermined particle size distribution, adding a fugitive binder, moulding a green ware, firing the green ware at a temperature in the range from 1400.degree. C. to 1800.degree. C., and furnace cooling the fired ware. Preferably the ware is held at the firing temperature for one hour.

Abstract: Method for producing a polycrystalline body comprised of from about 50% by weight to about 95% by weight of zircon and from about 5% by weight to about 50% by weight of cordierite, said body having a density greater than 85% of its theoretical density.

Abstract: Disclosed is a nasicon compound and a method of making it. The nasicon compound is rhombohedral at room temperature and has the general formulaM.sub.1+x+O.02y+0.04z M'.sub.2-0.02(y+z) M".sub.0.02y M"'.sub.0.02z M"".sub.x M""'.sub.3-x O.sub.12where M is selected from lithium, sodium, calcium, and silver, M' is selected from zirconium, titanium or hafnium, M" is selected from yttrium, scandium or lanthanum, M"' is selected from magnesium, calcium, strontium or barium, M"" is selected from silicon and germanium, M""' is selected from phosphorous and arsenic, x is about 1.6 to about 2.2, y is about 0 to about 15, and z is about 0 to about 15. The preferred compound isNa.sub.1+x Zr.sub.2 Si.sub.x P.sub.3-x O.sub.12.A sodium sulfur battery using the nasicon compound is also disclosed.

Abstract: A superrefractory dry ramming material based on zirconium oxide for the lining of induction-type crucible furnaces comprising a zirconium oxide low in SiO.sub.2 and conventionally stabilized with CaO, MgO, Y.sub.2 O.sub.3, rare earths or their mixed oxides which has a particle size ranging from 0 to 8 mm, and from 5 to 40 weight percent finely divided monoclinic, fused zirconium oxide containing less than 0.5 weight percent SiO.sub.2.

Abstract: Vibratable, monolithic refractory mixes useful to form linings for receptacles and related apparatus components used to handle or treat molten metal, such as ladles, tundishes, troughs and runners, including novel binders therefor.

Abstract: Aggregate-containing products bonded by an aluminosilicate hydrogel are disclosed. A system of two-part mixing and blending of binder components with various granular-like aggregates, modifiers and/or fillers is described in which the resulting compositions are temporarily fluid and formable for short, controllable periods of time but which thereafter become strong, rigid, adherent, erosion resistant composites, requiring little or no external heat supply to achieve full set. The compositions can be formulated for molding on suitable forms or patterns, and may also be prepared in slurry form suitable for spray coating or sealing applications. A wide variety of products can be manufactured of the compositions, including investment molds and cores for foundry use, as well as non-foundry products such as heat and electrical insulators, construction blocks, panels, coating slurries, etc. which may be of essentially solid or foamed (cellular) construction.

Abstract: A highly densified chromium oxide-based sintered body is produced by heating a powder mixture of chromium sesquioxide and at least one substance selected from silica, zirconia and zircon in a carbon powder. The highly densified chromium oxide-based sintered body has excellent resistance to corrosion and excellent heat shock resistance, and thus is useful as a refractory material.

Abstract: Granular compositions are disclosed for use in preparing hard, water and erosion-resistant, shapes such as foundry molds and cores, that are self-setting under ambient atmospheric conditions to allow such shapes to be stripped from patterns on which they are formed, such pattern stripping being possible immediately after forming in the case of foundry cores and the like, and within controllable pattern strip times as low as 60 seconds for foundry molds. The shapes may be used without baking and, in the case of foundry molds and cores, are ready for casting molten metal within as little as one hour. Molds and/or cores free of organic materials can be formed with the novel compositions, providing essentially carbon-free surfaces at the mold-metal interface, as well as being free of other deleterious elements such as sulfur, phosphorus and boron, thereby avoiding alloy composition alteration at the interface due to migration during casting.

Abstract: There is provided a metallurgical well powder having reduced tendencies to hinder the flow of molten metal, by packing and jamming the opening, in a steel ladle for example, through which said molten metal will be teemed upon tapping said ladle.