Abstract: Pressureless sintering of silicon carbide to produce ceramic bodies having 75% and greater theoretical densities, can be accomplished by firing shaped bodies, containing finely divided silicon carbide, boron source such as boron carbide, carbon source such as phenolic resin and a temporary binder, at a sintering temperature of from about 1900.degree. C. to about 2500.degree. C.

Abstract: Silicon dioxide containing waste flue dust from the production of silicon metal and silicon alloys is converted to crystalline zeolite molecular sieves of type A by (1) dissolving the flue dust in alkali metal hydroxide solution with the formation of alkali metal silicate solution having a module (SiO.sub.2 :Me.sub.2.sup.I O) in the range of 2.0:1 to 3.5:1 at a temperature of 60.degree.-100.degree. C.; (2) purifying the thus obtained alkali metal silicate solution from organic constituents by treatment with activated carbon and/or an oxidizing agent and separating the non-decomposable residue from the solution; and, (3) reacting alkali metal aluminate solution present at room temperature with the diluted, purified alkali metal silicate solution with a module (SiO.sub.2 :Na.sub.2 O) of 2.0:1 to 3.5:1 obtained by steps (1) and (2) and subsequently crystallizing the reaction mixture ((2.0-4.4)Na.sub.2 O:Al.sub.2 O.sub.3 ; (1.3-1.8)SiO.sub.2 :(90-120)H.sub.2 O) at a temperature of 90.degree.-95.degree. C.

Abstract: SIALON sintered product having the formulaSi.sub.6-z Al.sub.z O.sub.z N.sub.8-z(z is 0 to 4.2) is produced by sintering a molded product of the starting materials for SIALON in the condition of covering the surface of said molded product with a mixed powder of Si.sub.3 N.sub.4 and SiO.sub.2 as main components in nitrogen gas atmosphere.

Abstract: A new zeolite structure, CSZ-1, has a composition 0.05 to 0.55 M.sub.2 O:0.45 to 0.95 Na.sub.2 O:Al.sub.2 O.sub.3 : 3 to 7 SiO.sub.2 :x H.sub.2 O where M is cesium and/or thallium and x is 0 to 10. The zeolite has utility in sorption, separation and catalytic applications. It is made by reacting together sources of silica, alumina, soda, cesia and/or thallia, together with a nucleating agent or solution, followed by hot aging at a temperature between 50.degree. and 160.degree. C.

Abstract: A material and method to decompose/dissociate water into hydrogen and oxygen. The material comprises a reactive alloy of an alkali metal and aluminum combined with a catalytically effective amount of an alloy comprising a metal selected from the platinum metal family and at least one metal selected from the group consisting of germanium, antimony, gallium, thallium, indium and bismuth.

Abstract: There are produced crystalline zeolite powders of Type A with the composition1.0.+-.0.2M.sub.2/n O:Al.sub.2 O.sub.3 :1.85.+-.0.5SiO.sub.2.yH.sub.2 Owhere M is a metal cation, n is it valence and y has a value up to 6 with 50 weight % of the particles not over 4.3.mu. and with a particle spectrum:______________________________________ Fraction (.mu.) Portion (weight %) ______________________________________ <3 18 to 38 <5 70 to 82 <10 93 to 99 <15 96 to 100 ______________________________________by hydrothermally crystallizing a SiO.sub.2, Al.sub.2 O.sub.3, Na.sub.2 O and water containing alkali aluminate, water, silicate synthesis mixture with an optional tempering step wherein in a given case during the crystallization or tempering step instead of stirring shearing forces are employed. The process comprises providing an aqueous alkali aluminate liquor having a temperature of 30.degree. to 100.degree. C. and containing 0.1 to 100 grams of Al.sub.2 O.sub.3 /l and 1 to 200 grams of Na.sub.

Abstract: A process for producing a carbon fiber features converting a precursor material under atmospheric pressure with heat but without sparging to a predetermined mesophase containing pitch, and thereafter continuing the heat treatment with sparging.

Abstract: There are produced crystalline zeolite powders of Type A with the composition1.0.+-.0.2 M.sub.2/n O:Al.sub.2 O.sub.3 :1.85.+-.0.5 SiO.sub.2 .multidot.y H.sub.2 Owhere M is a metal cation, n is its valence and y has a value up to 6 with 50 weight % of the particles not over 6.2.mu. and with a particle spectrum:______________________________________ Fraction (.mu.) Portion (weight %) ______________________________________ <3 10 to 60 <5 25 to 95 <10 80 to 99 <15 92 to 100 ______________________________________by hydrothermally crystallizing a SiO.sub.2, Al.sub.2 O.sub.3, Na.sub.2 O and water containing alkali aluminate, water, silicate synthesis mixture with an optional tempering step wherein in a given case during the crystallization or tempering step instead of stirring shearing forces are employed. The process comprises providing an aqueous alkali aluminate liquor having a temperature of 50.degree. to 90.degree. C. and containing 0.1 to 100 grams of Al.sub.2 O.sub.3 /l and 1 to 200 grams of Na.

Abstract: There are produced crystalline zeolite powders of Type A with the composition1.0.+-.0.2 M.sub.2/n O:Al.sub.2 O.sub.3 :1.85.+-.0.5 SiO.sub.2 .multidot.y H.sub.2 Owhere M is a metal cation, n is its valence and y has a value up to 6 with 50 weight % of the particles not over 4.9.mu. and with a particle spectrum______________________________________ Fraction (.mu.) Portion (weight %) ______________________________________ <3 10 to 60 <5 55 to 95 <10 93 to 99 <15 96 to 100 ______________________________________by hydrothermally crystallizing a SiO.sub.2, Al.sub.2 O.sub.3, Na.sub.2 O and water containing alkali aluminate, water, silicate synthesis mixture with an optional tempering step wherein in a given case during the crystallization or tempering step instead of stirring shearing forces are employed. The process comprises mixing with stirring (1) an aqueous alkali silicate solution and (2) an aqueous sodium hydroxide with a NaOH content of 0.

Abstract: There are produced crystalline zeolite powders of Type A with the composition 1.0.+-.0.2 M.sub.2/n O:Al.sub.2 O.sub.3 :1.85.+-.0.5 SiO.sub.2 .multidot.y H.sub.2 O where M is a metal cation, n is its valence and y has a value up to 6 with 50 weight % of the particles not over 5.9.mu. and with a particle spectrum______________________________________ Fraction (.mu.) Portion (weight %) ______________________________________ <3 15 to 25 <5 35 to 55 <10 80 to 94 <15 96 to 100 ______________________________________by hydrothermally crystallizing a SiO.sub.2, Al.sub.2 O.sub.3, Na.sub.2 O and water containing alkali aluminate, water, silicate synthesis mixture with an optional tempering step wherein in a given case during the crystallization or tempering step instead of stirring shearing forces are employed. The process comprises providing water in a container, simultaneously feeding into the water at a temperature of 30.degree. to 100.degree. C.

Abstract: There are produced crystalline zeolite powders of Type A with the composition 1.0.+-.0.2 M.sub.2/n O:Al.sub.2 O.sub.3 :1.85.+-.0.5 SiO.sub.2 .multidot.y H.sub.2 O where M is a metal cation, n is its valence and y has a value up to 6 with 50 weight % of the particles not over 4.0.mu. and with a particle spectrum______________________________________ Fraction (.mu.) Portion (weight %) ______________________________________ <3 35 to 60 <5 82 to 95 <10 93 to 99 <15 96 to 100 ______________________________________by hydrothermally crystallizing a SiO.sub.2, Al.sub.2 O.sub.3, Na.sub.2 O and water containing alkali aluminate, water, silicate synthesis mixture with optionally a tempering step wherein in a given case during the crystallization or tempering step instead of stirring shearing forces are employed. The process comprises providing an aqueous alkali silicate soluton, heating it to a temperature between 30.degree. and 80.degree. C.

Abstract: A product suitable for the production of fuel gas upon reaction with water which is prepared by reacting a uniform mixture of finely divided calcium oxide and carbon under pressure in the presence of pyrophosphoric acid.

Abstract: An improved process for manufacturing high-grade and high-quality graphite fibers by the steps of (a) heating carbon fibers from acrylic fibers in an initial heating zone while exposed to an atmosphere of inert gas having a maximum temperature from about 1700.degree. C. to 1900.degree. C., and (b) then heating the resulting fibers in a subsequent heating zone while exposed to an atmosphere of inert gas having a maximum temperature from 2300.degree. C. to 2700.degree. C.

Abstract: Diamond crystals of controlled impurity content and/or impurity distribution and reaction vessel configurations for the production thereof are described. Combinations of "dopant", "getter" and "compensator" materials are employed to produce gem stones of unusual color patterns, or zoned coloration, using specific reaction vessel configurations.

Abstract: There are provided crystalline chromosilicates, their methods of preparation, and process uses. A first crystalline chromosilicate comprises a molecular sieve material providing a specific X-ray diffraction pattern and having the following composition in terms of mole ratios of oxides:0.9.+-.0.2 [WR.sub.2 O+(1-W)M.sub.2/n O]: Cr.sub.2 O.sub.3 : YSiO.sub.2 : ZH.sub.2 O,wherein R is an alkylammonium cation, M is at least one cation having a valence of n, Y is a value within the range of about 4 to about 500, Z is a value within the range of about 0 to about 160, and W is a value that is greater than or equal to 0 and less than or equal to 1. A second crystalline chromosilicate comprises a molecular sieve material providing a specific X-ray diffraction pattern and having the following composition in terms of mole ratios of oxides:0.9.+-.0.2 M.sub.2/n O: Cr.sub.2 O.sub.3 : YSiO.sub.2 : ZH.sub.

Abstract: The hydrophobicity of crystalline zeolites is enhanced and their catalytic activity altered by treatment with fluorine under controlled conditions which result in dealumination and structural stabilization as evidenced by changes observed in their infrared framework spectra.

Abstract: An improved method for synthesizing improved crystalline zeolites characterized by an alumina to silica mole ratio of not greater than 0.083 and a constraint index within the approximate range of 1 to 12 is provided. The improved method comprises forming a reaction mixture containing one or more sources of alkali metal oxide, organic nitrogen-containing cations, hydrogen ions, an oxide of silicon, water, and optionally, an oxide of aluminum, wherein the mole ratio for hydroxide ions/silica in said reaction mixture is zero and the mole ratio of H.sup.+ (additional)/silica in said reaction is between 0 and 1.0, and wherein the pH of said reaction mixture is at least about 7, and maintaining the reaction mixture at a temperature and pressure for a time necessary to crystallize therefrom said crystalline zeolite. Improvement in the present synthesis method resides, for example, in reduced crystallization time and reduced organic nitrogen-containing cation source requirement.

Abstract: Stoichiometric combustion conditions are provided at a location remote from reactor walls in a carbon black process and apparatus by injecting radially inwardly hot combustion gases of a complementary composition with respect to the hot combustion gases introduced tangentially into the reactor.

Abstract: Disclosed is an alkali calcium silicate having two different X-ray diffraction patterns: (1) with diffraction peaks at spacings (d) of 11.8-12.2 A, 6 A and 3 A or (2) with diffraction peaks at spacings (d) of 13.0-13.4 A, 6.7 A and 3.1 A. This silicate is in the fibrous or micaceous form and is valuable as a drying agent or an ion exchange agent. This silicate is prepared by hydrothermal reaction of an aqueous suspension having a specific composition of the starting components.

Abstract: Solid carbon material having extremely high flexural strength can be produced by introducing a sufficient amount of functional group to satisfy the undernoted general equation into a pitch having a H/C atomic ratio of 0.8 at most, thereby obtaining precursory carbon material; shaping said precursory carbon material into a desired article without using any binding material; and carbonizing or further graphitizing said article; wherein the general equation is ##EQU1## where, H/C is the hydrogen-to-carbon atomic ratio of the pitch, R is a numeral ranging from 0.2 to 0.3, and f is the percent by weight of at least one of oxygen, sulfur and halogen contained in the total functional groups introduced into the precursory carbon material on the basis of the weight thereof.