Abstract: Sintered silicon carbide/carbon composite ceramic body having a homogeneous very fine grain microstructure with at least 50 percent of its silicon carbide grains having a size not exceeding about 5 microns and an aspect ratio less than about 3, with graphite grains having an average size not exceeding that of the silicon carbide grains uniformly dispersed throughout the matrix of silicon carbide and having a density of at least 75 percent of theoretical can be made by firing of an infiltrated, microporous shaped green body having prior to infiltration a density of at least about 45 percent of theoretical, the shaped green body being infiltrated with an organic material which can be coked at elevated temperatures to form carbon, a sintering aid selected from the group consisting of aluminum, beryllium or boron or compounds containing any one or more of these or a mixture of any of the foregoing elements or compounds, silicon carbide having a surface area of from about 5 to about 100 square meters/gram and, opt

Abstract: Dielectric ceramics represented by the following general formula and substantially having the K.sub.2 NiF.sub.4 type crystal structure,aSrO.bCaO.cTiO.sub.2.dSnO.sub.2(wherein 0.39.ltoreq.a.ltoreq.0.70, 0.ltoreq.b.ltoreq.0.28, 0.27.ltoreq.c.ltoreq.0.35, 0.ltoreq.d.ltoreq.0.04, and a+b+c+d=1), have a high dielectric constant and an unloaded Q as high as 6000 and more in the high-frequency region of super high frequency band, and are therefore best suited for use in dielectric resonators, dielectric substrates for micro wave integrated circuit, and the like.

Abstract: A silicon carbide-graphite composite material is disclosed. The composite material includes graphite as a secondary phase which are dispersed uniformly in a grain boundary of the silicon carbide. The graphite have an average grain size of not more than 3 .mu.m and are present in a proportion of 1 to 20 vol % based on the volume of the silicon carbide. The composite material has a density greater than 90% of the theoretical density. A process for producing the silicon carbide-graphite composite material is also disclosed. The composite material is a high-density and high-strength material.

Abstract: A hydraulic cement mix comprising a hydraulic cement, aggregate in an amount of up to 80% by weight based upon the total weight of said cement mix, sufficient water to effect hydraulic setting of the cement, and an air-entraining additive consisting essentially of a coconut fatty acid diethanolamide produced by reacting alkyl ester of coconut acid with diethanolamine, said additive being in an effective amount whereby air will be entrained in said mix in an amount of 3% to 9% by volume of said mix.

Abstract: The present invention provides a concrete composition having a heat resisting property and dimensional stability, which comprises a cement selected from the group consisting of a self-hardening cement, a latent hydraulic material, a mixed cement and a thermosetting cement, a hydraulic material, an aggregate, a carbonaceous material acting as a binder and selected from the group consisting of a powdered coke and pitch coke, and potassium titanate whisker. Since the concrete composition of the invention is resistant to firing and can be used at a high temperature, a solidified mass prepared therefrom can be applied with a glaze and heated to have an enamelled surface.

Abstract: In a process of thermally treating fine-grained solids, the latter are preheated in a plurality of heat exchange stages by means of exhaust gases flowing in two parallel exhaust gas lines and are subsequently heated only by exhaust gases from a furnace and are then fed to the reaction vessel and subsequently to the furnace. The two exhaust gas streams are supplied with a mixture of exhaust gases from the furnace and exhaust gases from the reaction vessel.To permit different condition in the heat exchange stages associated with the two exhaust gas lines to be taken into account, two partial streams of exhaust gases are withdrawn from the reaction vessel and supplied to respective ones of the exhaust gas lines. Two partial streams of exhaust gases from the furnace are admixed to respective ones of said partial exhaust gas streams from the reaction vessel.

Abstract: A hydraulic cement composition containing specific additives and a process for producing a cement shaping using the same are disclosed. The hydraulic cement composition can be easily placed within a framework and provide a cement shaping having an improved compressive strength and an excellent appearance.

Abstract: A process for producing cellular concrete articles in the so-called pre-foam fashion, comprises molding a mixture (D) of a cement compound slurry (A) comprising calcium silicate and a rapid-hardening cement compound slurry (B) comprising calcium aluminate and an aqueous foamed liquid (C), and subjecting the molded article to hydrothermal curing, both the slurries (A) and (B) containing specified certain cement-setting retarders, respectively. By the synergistic effect of these two different retarders, an exotherm dwell period is provided in the initial setting stage of the foamed mixture (D).

Abstract: A magnesia-calcia clinker having a high density, said clinker containing MgO, CaO and Fe.sub.2 O.sub.3 as oxides, having the following chemical composition in percent by weightMgO, CaO and Fe.sub.2 O.sub.3 : at least 99% in totalMgO: at least 10%Fe.sub.2 O.sub.3 : 0.2-5%and having a density corresponding to at least 97.5% of the theoretical density. The above magnesia-calcia clinker can be produced by adding a water-soluble iron compound to sea water, bittern or brine, simultaneously with, or after, the addition of the water-soluble iron compound, adding a calcined product of dolomite, lime or a hydrate thereof to form a precipitate composed mainly of magnesium hydroxide, mixing the resulting magnesium hydroxide with a calcium compound, and dead-burning the resulting mixture.

Abstract: An inorganic, aqueous molding composition is described which can be hardened at low temperatures into molded parts having a high flexural stress at break.The molding composition is produced from electrostatic precipitator ash of high-temperature coal-burning power plants, this ash containing 45-55% by weight of vitreous SiO.sub.2 in addition to Al.sub.2 O.sub.3, or from calcined bauxite by reaction with an alkaline alkali silicate solution at a low temperature; fillers being optionally present.

Abstract: The present invention is directed toward a building material comprising from 20 to 70% of a reactive amorphorous silicate material which has been reacted with an aqueous solution of an iron salt, from 20 to 60% by weight of a filler containing reactives polyvalent cations, from 10 to 50% by weight of lime and from 0 to 10% by weight of reinforcing fillers, and to a method of producing same.

Abstract: The invention relates to a process for the disposal of combustible refuses in the manufacture of cement clinker by preheating and partly calcining the cement raw meal in a preheater, burning in a rotary kiln and subsequently air cooling the clinker, the refuse being separately burned and the flue gas obtained thereby transfers its heat to the cement raw meal. In the process according to the invention, hot exhaust air of the clinker cooler is fed to the refuse incineration and flue gas having a temperature of from 1000.degree. to 1400.degree. C. is produced during said incineration by means of which the cement raw meal is calcined. The slag of the refuse incineration is separately discharged.

Abstract: A ZrB.sub.2 composite sintered material consisting essentially of at least 1% by weight of SiC, at least 1% by weight of BN, at most 20% by weight of AlN, at most 20% by weight of B.sub.4 C, the rest being substantially ZrB.sub.2, provided that the total amount of SiC and BN is from 2 to 50% by weight.

Abstract: The invention provides a novel method for the preparation of a finely divided powder of silicon carbide as a promising material for sintered ceramic products of silicon carbide. The method comprises vapor-phase pyrolysis of a vaporizable organosilicon compound having, in a molecule, at least two, e.g. 2, 3 or 4, silicon atoms and at least one hydrogen atom directly bonded to the silicon atom but having no oxygen or halogen atom directly bonded to the silicon atom at a temperature of 750.degree. C. or higher.

Abstract: Silicon tetrachloride, hydrogen and metallurgical silicon are reacted at about 400.degree.-600.degree. C. and at pressures in excess of 100 psi, and specifically from about 300 up to about 600 psi to form di- and trichlorosilane that is subjected to disproportionation in the presence of an anion exchange resin to form high purity silane. By-product and unreacted materials are recycled, with metallurgical silicon and hydrogen being essentially the only consumed feed materials. The silane product may be further purified, as by means of activated carbon or cryogenic distillation, and decomposed in a fluid bed or free space reactor to form high purity polycrystalline silicon and by-product hydrogen which can be recycled for further use. The process results in simplified waste disposal operations and enhances the overall conversion of metallurgical grade silicon to silane and high purity silicon for solar cell and semiconductor silicon applications.

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: An additive used in the production of concrete blocks comprises a mixture of water with attapulgite or peptized calcium bentonite. Problem concrete blocks which previously were normally subject to improper molding or cracking during the molding, unmolding, handling and curing steps during the manufacture thereof, are now easily produced and properly molded without cracking resulting during any of these steps. Whereas, it was previously nearly impossible to manufacture any acceptable concrete blocks without employing sufficient quantities of fines in the concrete block mix, the additive allows formation of acceptable concrete blocks in the absence of any fines at all, thereby enabling much more reliable production of standard blocks, thin-walled blocks, and even more lightweight blocks than heretofore possible, because the gradation and characteristics and relative proportions of the coarse and fine constituents of the aggregate in the mix are rendered far less critical than heretofore.

Abstract: Improved therapy members useful for treating of sprains, muscle aches, orthopedic and skin injuries such as burns and other wounds are provided which make use of a pliable, self-sustaining, moisture sorbing gel including a humectant such as glycerin entrapped within a synthetic resin polymer matrix (e.g., a matrix containing acrylic acid or acrylamide monomer moieties). In one preferred embodiment, a body of the gel is encased within heat and moisture-permeable stretch fabric, and securing ties or the like are provided to permit the composite to be conformed to a body part and held in place. In use, such therapy wraps are either heated (as in a microwave oven) or refrigerated, so as to provide appropriate thermal treatment; it has been found that the preferred gel of the invention retains its pliability and other physical properties over a very broad temperature range, such as -20.degree. to 305.degree. F., and therefore the wraps of the invention can be used in many treatment contexts.

Abstract: Ground milk-of-lime grit with a maximum grain size of 0.75 mm is mixed with calcium or magnesium chloride and water to form a pumpable mixture which sets into an acid soluble mass only after about 1.5 to 4 hours.

Abstract: The invention is concerned with a method for controlling the quick setting of a pourable raw mixture having a filler material, water, a cement that contains at least in part an aluminate capable of reacting with calcium hydroxide, in particular aluminum oxide cement, with an organic substance, in particular, hydro-oxycarboxylic acid, serving as a set-up retarder for the aluminate, complex forming, and stunting the growth of calcium aluminum sulfate hydroxide, and further of calcium hydroxide and in some instances, foam. In order to come up with the minimum possible number of cement components for the hardening of the raw mixture, and in order to achieve good control of the charging time and set-up process with the possibility of achieving adequate hardness in a matter of minutes, the aluminate is premixed with the organic set-up retarder and the calcium sulfate in a calcium hydroxide-free environment sometimes together with additional stabilizing components of the raw mixture.