Abstract: The present invention concerns synthetic mica powder containing from 75 to 99% of the stoichiometrical composition of fluorine and/or having a shape in which the end face of particle is laminated, process for producing such synthetic mica powder, as well as cosmetics having synthetic mica powder blended therewith, in which the synthetic mica powder shows no leaching of fluorine ions and/or improved hold of oils due to lamination at the surface of powder. Accordingly, in this invention, cosmetics excellent in extensibility, gloss, adherence and modability, having appearance of high chroma and of high stability and safety can be obtained.

Abstract: A process for production of high purity, sub-micron size, silicon carbide by reacting a mixture of silica powder and carbon powder in a mixing reactor. The reactor, initially pressurized with a non-reactive gas, is indirectly heated and when the charge reaches reaction temperature a vacuum is applied. The charge is kept under a high vacuum until the reaction is complete, and is agitated to encourage release of carbon monoxide. After removal of excess carbon by low temperature oxidation, the product typically contains in excess of 99.5% silicon carbide of the beta-phase, has a surface area greater than 10m.sup.2 /gm, is free of carbon and contains no detectable unreacted silica. The product requires no post production treatment such as grinding and acid leaching.

Abstract: Air contaminated with chemical and biological pollutants is purified by treating chemically and electrochemically in a closed system minimizing the generation of by-products for disposal. Pollutants are treated in a scrubber zone with a scrubber liquid-electrolyte comprising pollutant degrading metal ions or complexed with inert metal ions and degraded either in an electrolyzer zone or in both the scrubber and electrolyzer zones where spent scrubber liquid-electrolyte is regenerated for further cleaning.

Abstract: This invention relates to a catalyst comprising a mixture of a primary refractory inorganic oxide having dispersed thereon at least one first active component selected from the group consisting of rare earth oxides and a secondary support consisting of zirconia, titania or cerium oxide having dispersed thereon at least one second active component which is a metal oxide, the metal selected from the group consisting of metals which form a stable sulfide said mixture having at least one main catalytic metal selected from the group consisting of platinum, palladium, rhodium, ruthenium and iridium deposited thereon. This invention also relates to a method of manufacturing said catalyst. Finally a method to minimize the formation of H.sub.2 S when automotive exhaust is contacted with a method is also claimed.

Abstract: This invention provides a process for removing H.sub.2 S from the gaseous stream by contacting the stream with an aqueous solution of a water soluble oxidized polyvalent metal chelate catalyst in the presence of oxygen whereby the metal chelate catalyst oxidizes the hydrogen sulfide to produce elemental sulfur and the oxygen present oxidizes the reduced metal chelate catalyst to its oxidized form. This process is performed in a single reaction vessel and forms a suspension or slurry of the precipitated elemental sulfur which is maintained in suspension by the use of a dispersing agent. The process is continued until the sulfur content reaches a level of 5 percent by weight or 10 percent or more by weight of the solution, then the entire solution is discarded and replaced with a fresh solution and the process repeated. This invention also provides a composition for H.sub.2 S removal comprising a polyvalent metal chelate catalyst, a buffer and a dispersing agent.

Abstract: The direct hydrothermal production of high purity sodium silicate solutions having a high SiO.sub.2 : Na.sub.2 O molar ratio by reaction of a silicon dioxide source with aqueous sodium hydroxide solutions, or with aqueous sodium silicate solutions having a lower SiO.sub.2 : Na.sub.2 O molar ratio, is made possible by using a silicon dioxide source that contains a sufficient fraction of cristobalite phase, or by conditioning other crystalline forms of silicon dioxide by heating at or above 1100.degree. C., but below the melting point of silica, before the hydrothermal treatment. Preferably the sodium hydroxide solution has a concentration range of 10 to 50% by weight, and the reaction is carried out in a closed pressure reactor at temperatures of 150.degree. to 300.degree. C. and under saturated steam pressures corresponding to those temperatures.

Abstract: Gases containing CO.sub.2 and/or H.sub.2 S in a first absorption stage, at from 40.degree. to 100.degree. C., with an aqueous absorption liquid containing from 20 to 79% by weight of methyldiethanolamine, the gas obtained at the top of the first absorption stage is fed to a second absorption stage in which, it is treated at from 30.degree. to 90.degree. C. with an aqueous absorption liquid which contains from 20 to 79% by weight of methyldiethanolamine and has a lower content of CO.sub.2 and/or H.sub.2 S than the absorption liquid fed into the first absorption stage, the treated gas is taken off at the top of the second absorption stage, the aqueous absorption liquid obtained at the bottom of the second absorption stage and preladen with CO.sub.2 and/or H.sub.2 S is fed to the top of the first absorption stage, the aqueous absorption liquid obtained in the lower part of the first absorption stage and laden with CO.sub.2 and/or H.sub.

Abstract: A method of producing submicron nonagglomerated particles in a single stage reactor includes introducing a reactant or mixture of reactants at one end while varying the temperature along the reactor to initiate reactions at a low rate. As homogeneously small numbers of seed particles generated in the initial section of the reactor progress through the reactor, the reaction is gradually accelerated through programmed increases in temperature along the length of the reactor to promote particle growth by chemical vapor deposition while minimizing agglomerate formation by maintaining a sufficiently low number concentration of particles in the reactor such that coagulation is inhibited within the residence time of particles in the reactor. The maximum temperature and minimum residence time is defined by a combination of temperature and residence time that is necessary to bring the reaction to completion.

Abstract: Disclosed is a process for reducing nitrogen oxides in an effluent from the combustion of a carbonaceous fuel under oxygen-rich conditions which minimize the production of carbon-based pollutants. A dispersion of a dilute aqueous urea solution is injected into an effluent at a temperature above 2000.degree. F., and preferably above 2100.degree. F. The concentration of the urea in solution and the size of the droplets in the dispersion are selected to provide the reduction in nitrogen oxides. The solution will preferably contain at least 80% by weight solvent and contain droplets sized within the range of from 150 to 10,000 microns.

Abstract: Amorphous silicas suitable for use as abrasives in transparent toothpastes can be prepared by a precipitation route. These silicas are distinguished by having a BET surface area of 420 to 550 m.sup.2 /g, a weight mean particle size of 5 to 20 micron, a perspex abrasion value of 15 to 28, a mean pore diameter from 3 to 8 nm and a transmission of at least 70% in the R1 range from 1.444 to 1.460.

Abstract: Hydrogen sulfide is removed from a fluid stream containing hydrogen sulfide and less than 500 ppm of free hydrogen by contacting the fluid stream under suitable absorbing conditions with an absorbing composition consisting essentially of a base material and nickel oxide. Said base material is selected from the group consisting of zinc oxide and zinc titanate, preferably combined with alumina.

Abstract: The present application relates to a method for production of trichloromonosilane in a fluidized bed reactor by reaction of silicon powder and HCl at a temperature between 280.degree. and 300.degree. C. wherein silicon powder which has been produced by gas atomization of molten silicon is used. The gas atomized silicon powder has a preferred particle size between 1 and 1000 .mu.m.

Abstract: A mixture of silica powder and carbon powder is heated in a mixture of NH.sub.3 gas and C.sub.m H.sub.n gas. Only silica powder may be heated in a mixture of NH.sub.3 gas and C.sub.m H.sub.n gas.

Abstract: Silica powder or a mixture of silica powder and silicon nitride whisker is heated at a temperature ranging from 800.degree. C. to 1,700.degree. C. in a gas mixture of ammonia gas (NH.sub.3) and hydrocarbon gas (C.sub.m H.sub.n) so as to produce silicon nitride whisker. The gas mixture flows at the rate of 10 mm/sec or less. The NH.sub.3 /CH.sub.4 ratio of the ammonia to the hydrocarbon, expressed as CH.sub.4, ranges from 0.5:1 to 2000:1 by volume. The silica powder is preferably mixed with at least one of six catalysts: transition metals; alkali metals; alkaline earth metals; halides of transition metals; halides of alkali metals; and alkaline earth metals. One mol part of the silica powder is mixed with 0.001-1.0 mol part of the catalyst.

Abstract: Quartz is purified by removing mineral impurities, particularly alkali metal impurities, from within the quartz crystal lattice structure. According to the disclosed process, quartz crystals are subjected to a pretreatment that removes surface bound impurities and then contacted with gaseous HCl at a temperature of from 800.degree. C. to 1600.degree. C. for a period of time of from a few minutes to several hours, thereby diffusing the mineral impurities to the quartz crystal surface where they form salts with chloride ion, removing the salts, and recovering the purified quartz crystals.

Abstract: Si.sub.3 N.sub.4 powder wherein the total oxygen content of the powder is 0.4% by weight or less is produced by preparing an amorphous Si.sub.3 N.sub.4 intermediate by reacting a Si-containing compound with an N-containing compound and the intermediate is then crystallized wherein "P", multiplication product of(i) the specific surface of the amorphous intermediate (BET in m.sup.2 /g),(ii) the moisture content C.sub.H.sbsb.2.sub.O (in volume ppm) of the atmosphere during handling and(iii) the time t in hours required for handling the amorphous intermediate,is kept smaller than the limit value product P.sub.G of 1000 in accordance with the following equation:"P"=BET (m.sup.2 /g).times.C.sub.H.sbsb.2.sub.O (vol ppm).times.t(h)<P.sub.G.

Abstract: A process for producing highly uniform microspheres of silica having an average diameter of 0.1-10 .mu.m from the hydrolysis of a silica precursor, such as tetraalkoxysilanes, which is characterized by employing precursor solutions and feed rates which initially yield a two-phase reaction mixture.

Abstract: A method of producing a .beta.-sialon fine powder which comprises using a silane compound represented by the general formula of SiH.sub.x Cl.sub.4-x (0.ltoreq.x.ltoreq.4) as a Si source, aluminum chloride as an Al source and an ether represented by the general formula of ROR' (R,R'=C.sub.y H.sub.2y+1, 1.ltoreq.y.ltoreq.5) as an oxygen source respectively, dissolving them in an organic solvent capable of dissolving them to obtain a solution, introducing ammonia gas into the solution to produce a precipitates, and burning the precipitates in a nonoxidative atmosphere. In the .beta.-sialon fine powder obtained by the method of the invention, respective elements of Si, Al, O and N are uniformly distributed in a chemical viewpoint. A high density high strength sintered body can be produced even at a relatively low temperature by using the .beta.-sialon fine powder.

Abstract: The present invention provides a coating for electrodes for use in electrochemical cells having an electrochemically active species and an electrolyte. The coating contains active species material and is selectively permeable allowing for the diffusion of the active species through the coating during operation of the cell while providing a substantially impervious barrier to the electrolyte. The coating optionally further includes a polymer layer over the active species containing coating or layer for maintaining the mechanical integrity of the active species layer.Electrodes utilizing the coatings described herein may be used in primary and secondary cells over a wide range of operating temperatures to deliver better electrochemical performance even at room temperature.Methods of making the coating and an apparatus for performing these methods on a continuous basis are disclosed.A novel composition of matter is disclosed comprising lithium, silicon, and fluorine prepared by exposing lithium metal to SiF.sub.

Abstract: Crystalline silicon carbide wherein at least 90 weight percent of the silicon carbide is formed from a plurality of hexagonal crystal lattices wherein at least 80 weight percent of the crystals formed from the lattices contain at least a portion of opposing parallel base faces separated by a distance of from 0.5 to 20 microns. The crystals may be in the form of separate particles, e.g. separate platelets, or may comprise an intergrown structure. The crystalline silicon carbide of the invention is produced by heating a porous alpha silicon carbide precursor composition comprising silicon and carbon in intimate contact to a temperature of from 2100.degree. C. to 2500.degree. C. in a non-reactive atmosphere. The materials are high performance materials finding use in reinforcing, high temperature thermal insulating, improvement of thermal shock resistance, and modification of electrical properties.