Abstract: Additive compositions, made up essentially of a mixture of a salt of a very high molecular weight condensation product of naphthalenesulfonic acid with formaldehyde, containing not less than 35% by weight of the condensation products with a molecular weight greater than 5000, together with a glucopheptonic acid salt, are mixed with hydraulic cement to reduce the water which needs to be added, and to provide improved strength.
Abstract: A method of producing silicon comprising producing a plasma in a gas flow laden with at least one silicon compound so that the silicon compound is reduced or decomposed to silicon and transporting the silicon which may have reacted with other material if present in the plasma and reaction products out of the plasma in the gas flow.
Abstract: An aqueous catalytic oxidation-reduction composition for oxidizing hydrogen sulfide to produce elemental sulfur and a method of removing hydrogen sulfide from a gas stream whereby a gas stream containing hydrogen sulfide is brought into contact with an aqueous catalytic oxidizing reaction composition containing a water soluble polyvalent metal salt having the metal in the higher valent state and at least one surfactant, preferably a low foaming nonionic surfactant, such as a linear alcohol alkoxylate surfactant, which is adapted to wet the elemental sulfur formed and having the surfactant present in the reaction solution in an amount sufficient to prevent formation of sulfur froth on the surface of the reaction solution.
Abstract: There is disclosed a method of using an exhaust gas catalyst for treatment of exhaust gases developed by burning a hydrocarbon based fuel in an internal combustion engine. These exhaust gases contain varying amounts of unburned hydrocarbons, carbon monoxide and oxides of nitrogen depending upon the operating conditions of the internal combustion engine. This specification teaches the use of an improved catalyst composition in which a support medium is provided for supporting the catalyst system, the support medium having an upstream support portion and a downstream support portion over which the exhaust gases pass in succession. The upstream support portion of the support medium has deposited thereon palladium and the downstream support portion of the support medium has deposited thereon palladium and tungsten. Tungsten is present on the downstream support portion of the support medium in a quantity such that tungsten is available to substantially all of the palladium on that portion of the support medium.
Abstract: Nitric oxide, NO, and nitrogen peroxide, NO.sub.2, are facilely removed from gaseous admixtures comprising the same, together with gaseous oxygen, advantageously in a plate tower for the commercial production of nitric acid, by countercurrently oxidizing/absorbing said gaseous feedstream in aqueous solution, in a gas/liquid phase contactor, and wherein that section of said phase contactor the NO.sub.x content in the gaseous feedstream is less than 6000 vpm, the improvement which comprises that the residence time in said less than 6000 vpm section of said phase contactor, is increased to a value such that the ratio K, of the liquid retention volume in cubic meters in said phase contactor to the rate of flow therein of said gaseous feedstream in Nm.sup.3 /hour, in excess of 5.10.sup.-4 hour.
Abstract: A process for removing SO.sub.x pollutants from a stack gas by (1) absorbing the SO.sub.x pollutants into an aqueous absorbent containing a formate compound and (2) regenerating the spent absorbent containing dissolved SO.sub.x compounds by contact, in the presence of added formate anion, with a water-insoluble, solid substance containing one or more tertiary amine functional groups. Nitrogen monoxide is removed by providing in the aqueous absorbent an iron(II) chelate, such as a chelate of ferrous ion with ethylenediaminetetraacetic acid. Regeneration of the spent absorbent containing absorbed NO is accomplished under the same conditions as for spent absorbents containing absorbed SO.sub.x compounds. SO.sub.x and NO pollutants dissolved in the absorbent are, during regeneration, converted to hydrogen sulfide and nitrogen, respectively.
Abstract: A process and apparatus for treating thiosulfate containing liquors such as coke oven gas scrubbing liquors in two stages of wet oxidation with intermediate removal of elemental sulfur. Mild oxidation conditions in the first stage results in conversion of thiosulfate sulfur to elemental sulfur, which is removed prior to second stage wet oxidation of the liquors to substantially reduce the liquor oxygen demand.
Abstract: A self-bonding flame spray wire capable of forming a readily grindable coating formed of a sheath of aluminum and a compacted powder core containing a major portion of nickel and stainless steel and a minor portion of aluminum and metal oxide. The core may contain from about 10 to 90 percent, and preferably about 61 percent, by weight nickel, about 10 to 90, and preferably 30, percent by weight stainless steel, from 1 to 10 percent by weight, and preferably 5 percent by weight, aluminum, from 1/4 to 10 percent by weight, and preferably 4 percent by weight, of the metal oxide which may, for example, be cobalt oxide or zirconium oxide, and is most preferably zirconium oxide.
Abstract: A method for controlling the concentration of dissolved thiosulfate byproduct which forms in a wet desulfurization process, by introducing a peroxygen chemical into its recirculating aqueous absorption medium. A peroxygen chemical such as aqueous hydrogen peroxide is introduced into the recirculating aqueous alkaline absorption medium, preferably after its regeneration, in an amount sufficient to maintain the concentration of thiosulfate byproduct below a saturation concentration. The method is applicable to cyclic wet desulfurization processes, used to recover elemental sulfur from H.sub.2 S-containing gas streams, in which the absorption medium contains a regenerable oxidizing agent and is subject to thiosulfate byproduct buildup.
Abstract: A process for producing silicon in which a reaction mixture consisting, on the one hand, of hot-pressed briquettes of silicon dioxide (quartz) and carbon and, on the other hand, of granular quartz are introduced into an electric furnace and reacted so that silicon carbide is produced from the agglomerates and the silicon carbide then reacts with the quartz which fuses from the granular quartz to produce elemental silicon.
July 8, 1981
Date of Patent:
December 28, 1982
International Minerals & Chemical Luxembourg Societe Anonyme
Abstract: A process is provided for removing impurities from a slurry of titanyl hydrate. The titanyl hydrate is separated from the slurry, washed, and reslurried with water to make the resulting titanyl hydrate slurry fluid. The reslurried titanyl hydrate slurry is then treated by the addition of a trivalent titanium compound in an amount between about 0.01 grams and about 0.7 grams trivalent titanium compound measured as TiO.sub.2 per 100 grams titanyl hydrate as calcined TiO.sub.2 in the absence of additional acid values. The titanyl hydrate is then separated from the treated slurry, washed and recovered.
Abstract: A tuyere for injecting hot reducing gases into a furnace is provided with an inlet pipe and a plasma oven whose gas outlet axis is inclined to the longitudinal axis of the tuyere. The angles which the outlet axis of the plasma oven and the inlet pipe form with the said longitudinal axis are such that the longitudinal axis is parallel to the vector sum of the amount of movement of the gases from the plasma oven and the inlet pipe respectively .
December 10, 1980
Date of Patent:
December 14, 1982
Centre de Recherches Metallurgiques-Centrum Voor Research in de Metallurgie, Societe Anonyme Cockerill
Abstract: A process is disclosed for desulfurization of gas streams by which reduced sulfur compound, such as H.sub.2 S, is reacted with solid sulfur removal metal oxide compound which is an oxide of chromium, combination of zinc and chromium, combination of zinc and aluminum and mixtures thereof at about 400.degree. to about 1600.degree. F. producing sulfided sulfur removal compound followed by regeneration of the sulfided compound by contact with oxygen containing gas at temperatures about 1400.degree. to about 2400.degree. F. to regenerate the sulfur removal metal oxide compound with at least 10 weight percent of the sulfur removed being in the form of elemental sulfur. The process does not consume valuable fuels, such as coke or fuel gases, and provides an environmentally acceptable off-gas with reduced amounts of SO.sub.x.
August 14, 1981
Date of Patent:
December 14, 1982
Institute of Gas Technology
Gerald L. Anderson, Harley A. Borders, F. Otis Berry
Abstract: A process for producing polycrystals of cubic boron nitride which comprises exposure of hexagonal boron nitride to a pressure of from 40 to 70 kbar at a temperature of from 1,200.degree. to 1,800.degree. C. When the conversion of hexagonal boron nitride to cubic boron nitride reaches 20 to 65% by weight, the heating is switched off and pressure is increased to a value of from 80 to 120 kbar. Then the heating is resumed and temperature is elevated to 1,800.degree.-3,000.degree. C. Under these conditions the process is continued to full conversion of hexagonal boron nitride to cubic modification thereof.The process can be conducted in the presence of 0.5 to 10% by weight of a catalyst contributing to the conversion of hexagonal boron nitride into its cubic modification. The main portion of the catalyst is concentrated in the central portion of the volume of hexagonal boron nitride, the remainder - in the peripheral portion.
April 27, 1982
Date of Patent:
November 30, 1982
Gennady M. Zhdanovich, Alexandr I. Dudyak, Mikhail I. Galkov, Vladimir P. Baraban, Jury V. Zherebtsov, Anatoly P. Zholob, Mikhail M. Zhuk, by Galina K. Zhuk, administrator
Abstract: A process for the recovery of selected metal values from silica containing sludges including incineration of the sludge to degrade organic components, followed by acid leaching of the ash, followed by hydrometallurgical recovery of metal values from the remaining solid and liquid residues, wherein the incineration step is carried out at a temperature below the slagging temperature of silicates, whereby to avoid the occluding of metal values in glass matrices which are not attacked by subsequent acid leaching and hydrometallurgical steps.
Abstract: Apparatus for controlling furnace temperature particularly in an annealing furnace used for annealing elongated product, such as pipe and tubing, on a continuous basis. The apparatus includes a pyrometer used to produce an electrical signal proportional to the temperature of the workpiece immediately after heating by an induction coil in the furnace, means for comparing this electrical signal to a set point signal proportional to the desired temperature of the workpiece and if these signals differ a control signal is produced to either increase or decrease the power input to the induction coil to correspondingly increase or decrease the temperature of the workpiece to the desired temperature.
Abstract: A novel process for the preparation of insoluble sulfur product comprises the steps of vaporizing sulfur, mixing the vaporized sulfur with from about 1.times.10.sup.-6 % to about 5% hydrogen sulfide, in the essential absence of hydrocarbon oil, quenching the vaporized sulfur in a quenching medium and separating the insoluble sulfur product from the quenching medium.
Abstract: A method of removing nitrogen oxides from waste gas exhausted from a heat power plant and any other various kinds of workshops, etc. is disclosed. The method comprises bringing the waste gas into contact with a honeycomb-shaped catalyst under the following three conditions, i.e.(1) a hydraulic diameter of each of the channels extending through the honeycomb-shaped catalyst is larger than 2.0 mm, preferably 2.0 mm to 30 mm,(2) an open frontal area is larger than 50%, preferably 50% to 80%, and(3) a waste gas speed is higher than 0.5 m/sec, preferably 0.5 m/sec to 60 m/sec.
Abstract: A method for the recovery of the bromine content of methyl bromide as bromine or hydrogen bromide comprises oxidizing the methyl bromide over a noble metal catalyst. The production of hydrogen bromide is favored by the inclusion of a source of hydrogen.
Abstract: Submicron titanium diboride powder and other hard, refractory metal boride powders, such as zirconium diboride and hafnium diboride powders, are prepared by vapor phase reaction of the corresponding metal halide, e.g., titanium halide, and boron source reactants in the presence of hydrogen in a reaction zone and in the substantial absence of oxygen, either combined or elemental. In a preferred embodiment, the metal halide, e.g., titanium tetrachloride, and boron source, e.g., boron trichloride, reactants are mixed with a hot stream of hydrogen produced by heating hydrogen in a plasma heater. The reaction zone is maintained at metal boride forming temperatures and submicron solid metal boride powder is removed promptly from the reactor and permitted to cool. The preponderant number of metal boride particles comprising the powder product have a particle size in the range of between 0.05 and 0.7 microns.