Abstract: The present invention relates to black magnetic iron oxide particles comprising magnetite as a main component, wherein when the black magnetic iron oxide particles are molded into a tablet shape, an electric resistance value of the tablet in an alternating current electric field is controlled to produce an impedance of not less than 2×106 ?cm as measured in a characteristic frequency range thereof. The black magnetic iron oxide particles according to the present invention can provide a toner capable of exhibiting a good charging performance and a uniform charging property under the high-temperature and high-humidity conditions, so that when developing an electrostatic latent image therewith, it is possible to obtain toner images having a high resolution or definition, and further the use of heavy metal elements in the black magnetic iron oxide particles can be minimized.

Abstract: Provided is an apparatus for producing magnesium-containing zinc oxide, including: zinc vapor producing means 11 which produces zinc vapor by heating metallic zinc; magnesium vapor producing means 15 which produces magnesium vapor by heating metallic magnesium; mixed vapor producing means 20 which produces mixed vapor by mixing the zinc vapor and the magnesium vapor; and oxidizing gas contact means 19 which produces magnesium-containing zinc oxide by bringing an oxidizing gas into contact with the mixed vapor. The content of zinc in the mixed vapor is adjusted to be higher than that of magnesium.

Abstract: A method ensuring that a CaMgSi2O6:Eu2+ blue light-emitting phosphor having high emission intensity can be produced in an industrially advantageous manner is provided. The production method includes a step of mixing a calcium source powder, a europium source powder, a magnesium source powder and a silicon source powder composed of silicon diimide powder or the like in a ratio producing a CaMgSi2O6:Eu2+ blue light-emitting phosphor, and a step of subjecting the powder mixture to heating at a temperature of 400 to 1,000° C. in an oxygen-containing gas atmosphere and then firing at a temperature of 800 to 1,500° C. in a reducing gas atmosphere.

Abstract: Provided is a method for forming zinc oxide which includes introducing a zinc vapor and a water vapor to a reactor; providing a zinc particulate to the reactor to promote the reaction between the zinc vapor and water vapor, thereby forming zinc oxide and hydrogen. An apparatus for forming zinc oxide is also provided.

Abstract: A release agent is flash evaporated and deposited onto a support substrate under conventional vapor-deposition conditions and a conductive metal oxide, such as ITO, is subsequently sputtered or deposited by reactive electron beam onto the resulting release layer in the same process chamber to form a very thin film of conductive material. The resulting multilayer product is separated from the support substrate, crushed to brake up the metal-oxide film into flakes, and heated or mixed in a solvent to separate the soluble release layer from the metallic flakes. Thus, by judiciously controlling the deposition of the ITO on the release layer, transparent flakes may be obtained with the desired optical and physical characteristics.

Abstract: A powdered photocatalyst and manufacturing method thereof are disclosed. The manufacturing method of the photocatalytic nanopowders is achieved by the non-transferred DC plasma apparatus in an atmosphere of nitrogen at around 1 atm. The nitrogen-containing gas is used as the plasma-forming gas. After the generation of the nitrogen-plasma in the non-transferred DC plasma apparatus, a plurality of solid Zn precursors are introduced to the nitrogen-plasma for vaporization and oxidization. The solid Zn precursors are vaporized and oxidized through homogeneous nucleation and are rapidly cooled down by a large amount of cooling gas (i.e. mixture of nitrogen and oxygen). After the cooling process, the tetrapod-shaped and nitrogen-doped photocatalytic ZnO nanopowders having wurtzite structure are formed.

Abstract: Nano-sized metal-bearing powders and doped-powders are synthesized by means of a process whereby a non-volatile metal-bearing precursor powder or powder mixture is dispersed in a hot gas stream at relatively low temperatures. A first volatile reactant is added, converting the metal in the precursor into a volatile metal compound. Subsequently a second volatile reactant is injected into the gas stream, converting the volatile metal compound into a solid, which condenses as a nano-sized metal-bearing powder upon quenching. Finally, the vapour/metal-bearing powder mixture is separated from the gas stream.

Abstract: The method for synthesizing metal oxide nanopowder produces powders of nanoparticle size from metals having relatively low boiling temperatures, such as zinc, tellurium, bismuth, and strontium by vapor-phase oxidation using a conventional 2.45 GHz microwave oven. The energy that initiates the combustion comes from the microwave through a susceptor tube that absorbs radiant microwave energy and transfers it to the metal, which evaporates to small particles inside the susceptor tube and then combusts in air to form nanosize powder. The susceptor is made of silicon carbide composite material.

Abstract: A process related to sodium chemicals production, including the processing of bicarbonate containing solutions obtained by solution mining of trona, nahcolite or wegscheiderite reserves and the lake waters containing bicarbonates, includes the steps of purification, evaporation-decarbonation, crystallization, centrifuging, and drying.

Abstract: A method of producing nanostructured zinc oxide powder. The method comprises introducing a source of zinc selected from metallic zinc or zinc compound and a process gas mixture which includes an oxidizing gas (the reactants) into a reactor. While in the reactor, the reactants are heated to a process temperature effective to vaporize the zinc and to react the reactants to form a powder product. The powder product is recovered.

Abstract: Method for producing metal oxide nanoparticles. The method includes generating an aerosol of solid metallic microparticles, generating plasma with a plasma hot zone at a temperature sufficiently high to vaporize the microparticles into metal vapor, and directing the aerosol into the hot zone of the plasma. The microparticles vaporize in the hot zone into metal vapor. The metal vapor is directed away from the hot zone and into the cooler plasma afterglow where it oxidizes, cools and condenses to form solid metal oxide nanoparticles.

Abstract: Disclosed are a method of fabricating ZnO nanostructures and its apparatus, and more particularly, to a method of fabricating ZnO nanostructures from Zn gas, which is produced by a reduction process between ZnO powder and graphite, on a silicon substrate, wherein various types of nanostructures are reproducibly generated by adjusting the processing temperature and the mixed ratio between oxygen and argon gases, which are introduced into the interior of a reaction tube as carrier gases, and its apparatus.

Abstract: A method of making an oxide compound, comprising subjecting a base material to a source of heat that produces a localized temperature in the range of 2,000 to 5,500 degrees Celsius that vaporizes the base material which is drawn upward above the surface of the base material where it oxidizes, after which the resulting oxide compound is collected. A method of making bismuth trioxide, comprising providing an electric arc between electrodes, wherein elemental bismuth is in touching proximity to one of the electrodes. The bismuth is evaporated, drawn upward off the surface of the molten metal, forms the bismuth oxide on contact with oxygen, and the particles of bismuth oxide are collected. A method of making an oxide using an electric arc to evaporate a base material which then reacts with oxygen, and collecting the resulting oxides of base material.

Abstract: A method of operating mechanical separation devices at high temperatures to separate various volatile metals, metal halides and metal oxides to produce high purity materials.

Abstract: Ultrafine particulates of highly white zinc oxide having a reduced average particle diameter of about 15 nm to about 55 nm as measured by the BET-one point method and that has an L value of about 90 or more as measured by a Hunter-type color-difference meter. Also, a process for producing ultrafine particulates of highly white zinc oxide, comprising oxidizing zinc vapor with an oxidizing gas in a reactor, wherein a zinc vapor-containing gas has a temperature of about 950° C. or more at a nozzle of the reactor for discharging the zinc vapor-containing gas and the oxidizing gas has a temperature of about 900° C. or more at a nozzle of the reactor for discharging the oxidizing gas is disclosed.

Abstract: A process for preparing zinc oxide comprises introducing, into an atmosphere, an aqueous solution of a zinc salt that is thermally decomposable to zinc oxide, the atmosphere having a temperature sufficient to decompose the salt to the oxide, and recovering zinc oxide. The zinc oxide so-prepared is in the form of discrete particles which can have an average particle size of 0.08 .mu.m or less in diameter and a surface area of at least 12.5 m.sup.2 /g and which is also free of zinc metal. The small particle size zinc oxide is particularly useful as a UV absorbing/scattering additive.

Abstract: Herein disclosed is a method for preparing electrically-conductive needle-like zinc oxide which comprises the steps of preparing a vapor mixture by admixing zinc vapor and vapor of at least one compound selected from the group consisting of dopant-forming compounds having boiling points of not more than the boiling point of zinc and free of oxygen atom in an amount of 0.005 to 5 parts by weight, as expressed in terms of the oxide of the dopant-forming metal, per 100 parts by weight of the zinc vapor as expressed in terms of zinc oxide; and passing the vapor mixture through an oxidation chamber while blowing an oxidizing gas into the vapor mixture through at least two nozzles spaced apart from one another and arranged along the flow path of the vapor mixture to thus stepwise oxidize the vapor mixture.

Abstract: A vapor of diethylzinc or dimethylzinc is reacted with water vapor to form very small particles of depleted zinc oxide which are entrained in the gas flow. In accordance with one version of the method, a spray nozzle is used to mix liquid diethylzinc with dry nitrogen to prevent combustion. The nozzle sprays the diluted diethylzinc into a chamber heated up to its boiling point of 118.degree. C. to completely vaporize the diethylzinc. The diluted diethylzinc gas is then reacted with water vapor to form a fume of very small zinc oxide particles entrained in ethane gas without combustion. A similar process can be used to convert dimethylzinc into depleted zinc oxide powder. In accordance with another version of the process, an inert gas stream is saturated with diethylzinc or dimethylzinc vapor by passing a dry inert gas through a vessel containing liquid diethylzinc or dimethylzinc. A second inert gas stream is saturated with water vapor in a similar manner.

Abstract: A method for preparing electrically-conductive zinc oxide is herein disclosed, which comprises the steps of preparing a vapor mixture comprising zinc vapor and vapor of at least one member selected from the group consisting of dopant-forming metal compounds having boiling points of not more than that of zinc and free of oxygen atom in a predetermined mixing rate ranging from 0.005 to 5 parts by weight of the dopant-forming metal, as expressed in terms of the oxide thereof, per 100 parts by weight of zinc, as expressed in terms of zinc oxide; then oxidizing the vapor mixture with an oxidizing gas.

Abstract: A composition of zirconyl hydroxy chloride and aluminum chlorhydroxide in stable solid form having improved antiperspirant efficacy when dissolved in water is made by heating a 2-20% by weight aqueous solution containing at least the aluminum chlorhydroxide component of the composition at a temperature of at least 50.degree. C. until the ratio of the height of peak 4 at Kd=0.7 to that of peak 3 at Kd=0.5 as measured by gel permeation chromatography on cross-linked dextran is at least 2:1, then subjecting the solution to rapid drying to solid form.

Abstract: Disclosed is a novel ultraviolet-shielding agent in a powder form consisting of particles of an inorganic material having a specified refractive index and a flaky particle configuration, such as mica, talc, sericite and the like, compositely coated with a water-insoluble cerium compound and amorphous silica each in a specified coating amount. A method for the preparation of such an ultraviolet-shielding agent is disclosed. By virtue of the excellent ultraviolet-shielding effect along with good translucency as well as stability and safety against human skin, it is useful as an ultraviolet-shielding ingredient in cosmetic compositions.

Abstract: Residual metallurgical materials which contain zinc and lead are reprocessed by a thermal treatment in a circulating fluidized bed. The required heat is generated in that solid carbon is combusted in the fluidized bed reactor of the circulating fluidized bed. A solid carbon content of 5 to 30% is maintained in the lower part of the fluidized bed. Oxygen-containing gases are supplied to the upper part of the fluidized bed reactor, and CO.sub.2 is formed only in such an amount that zinc metal will not be reoxidized. Substantially all solids are removed from the discharged suspension in a recycle cyclone and are recycled. The gas is cooled to a temperature at which zinc metal is oxidized to ZnO. The dustlike compounds of zinc and lead are separated from the gas.

Abstract: A method for the recovery of metals including zinc, zinc oxide, iron-carbon feedstocks, lead and cadmium from industrial waste streams which entails treating the waste streams with carbon and an ammonium chloride solution, separating any undissolved components from the solution, displacing metal ions including lead and cadmium from the solution using zinc metal, further treating the solution to remove zinc compounds therefrom, further treating the zinc compounds and the undissolved components with a dissolving solution, and further treating the displaced metal ions to recover lead, cadmium and zinc therein using various methods including electrolysis.

Abstract: Antiperspirant effectiveness of basic aluminum chloride is increased by mixing it with monosilicic acid in aqueous solution. The product can be dried to a solid, and the antiperspirant effectiveness does not decrease in contact with water. The product can also be characterized by size exclusion chromatography of its approximately 10% by weight aqueous solution. Zirconyl hydroxy chloride may also be present.

Abstract: A voltage non-linear resistor element mainly comprising ZnO, substantially free from internal defects, exhibiting an excellent current impulse withstand capability, can be manufactured by a process wherein an SiC inclusion in the starting ZnO powder is restricted to at most 10 ppm, preferably at most 0.1 ppm, by weight, whereby formation of closed pores in the element is prevented, which is otherwise caused by decomposition of considerable amount of SiC during firing. The starting ZnO powder has an average particle diameter (R) of 0.1-2.0 .mu.m, preferably 0.3-0.8 .mu.m, a particle size distribution within the range of between 0.5R and 2R, of at least 70%, preferably 80%, by weight, needle-like crystals of at most 20%, preferably at most 10%, by weight, and an SiC content as an impurity of at most 10 ppm, preferably at most 0.1 ppm, by weight.

Abstract: A method for the recovery of zinc oxide from industrial waste materials of various components, including zinc, lead, iron and cadmium, comprising the steps of treating the waste material with an ammonium chloride solution maintained at an elevated temperature, separating the undissolved components from the solution, treating the solution with zinc metal to displace undesired metal ions from the solution, cooling the solution to precipitate therefrom zinc compounds, washing the precipitated zinc compounds to remove unwanted compounds such as diamino zinc dichloride, and drying the remaining zinc compound which is essentially hydrated zinc oxide, resulting in essentially pure zinc oxide.

Abstract: A zinc- and lead-containing residue from a metallurgical plant is reprocessed by a thermal treatment in a circulating fluidized bed system. A major part of the heat demand is satisfied by a combustion of solid carbonaceous material in the fluidized bed reactor of the circulating fluidized bed system. A reducing fluidizing gas, which is virtually free of free oxygen, is fed to the lower part of the fluidized bed reactor. A solid carbon content of from 5 to 30% is adjusted in the fluidized bed in the lower portion of the fluidized bed reactor, which is supplied in its upper portion with oxygen-containing gases and in which CO.sub.2 is formed only at such a rate that zinc metal is not reoxidized. Substantially all solids are removed in a recycling cyclone from the suspension discharged from the reactor and the removed solids are recycled. The gas is cooled to a temperature at which zinc metal is oxidized to ZnO. The dust-like zinc compounds and lead compounds are removed from the gas.

Abstract: This invention relates to the metallurgy of iron and particularly to the separation and recovery of metals from electric arc furnace (EAF) dusts. While the invention discloses a process for the separation and recovery applicable to zinc, lead, cadmium and antimony contained in such EAF dusts, the invention is particularly applicable to the separation and recovery of zinc. This invention describes a method for reducing the zinc contained in an EAF dust, volatilizing the metallic zinc so produced from the mass of the dust, and reoxidizing the metallic zinc to zinc oxide along with the simultaneous regeneration of hydrogen which can be recycled to treat additional EAF dust.

Abstract: Ultra-fine spherical particles of a metal oxide having an average particle diameter of 40 nm or smaller can be prepared by a method in which a vaporizable metal compound is vaporized and decomposed under heating to give ultra-fine particles of a metal oxide followed by immediate cooling down to a temperature at which coalescence of the fine particles are prevented from coalescence. The fine particles have characteristics such as an excellent power of ultraviolet scattering.

Abstract: A method for recovering zinc from substances containing a zinc compound which comprises supplying a carbonaceous substance and a zinc compound-containing substance onto the hearth layer in a sintering apparatus, vaporizing the zinc compound in said substance as metal to separate the compound therefrom by forming a locally strong reducing atmosphere at the combustion temperature of sintering material, oxidizing the resultant vapor-form zinc into zinc oxide under a strong oxidizing atmosphere, and then discharging the resultant zinc oxide as such from said sintering apparatus.

Abstract: A method for removing carbonaceous impurity from zinc oxide by contacting a water slurry of contaminated zinc oxide with oxygen in a reactor at reaction conditions sufficient to produce oxide products of the carbon contaminants and passing the reactor effluent through a filter to collect solid zinc oxide while passing the oxides of carbon through the filter. In a preferred embodiment, contaminated zinc oxide separated from the reaction product in the preparation of terephthalic acid from benzoic acid using zinc benzoate catalyst is subjected to treatment for removal of carbonaceous contaminants before being recycled to reaction with molten benzoic acid to produce zinc benzoate catalyst used in the reaction.

Abstract: This invention describes a process for preparing a yellow iron hydroxide pigment from inorganic ferrous salts and aromatic nitro compounds.

Abstract: A carbon source and zinc oxide are reacted in a reactor to form a gas consisting essentially of carbon monoxide and zinc; the zinc is separated from the gas and reoxidized in indirect heat exchange relationship with the reaction mixture of the carbon source and the zinc oxide. A portion of the carbon monoxide and zinc-comprising gas formed can be recycled to the reactor as a fluidizing gas.

Abstract: A carbon monoxide- and zinc-containing gas is produced by the endothermic reaction of a carbonaceous material with zinc oxide. Zinc separated from the gas is in part reoxidized with air and in part reoxidized with H.sub.2 O to form zinc oxide both in exothermic reactions. Heat developed in these exothermic reoxidations is transferred to the endothermic CO-forming reaction so that the total system is thermally neutral, in other words neither generates nor consumes heat.

Abstract: A carbon source and zinc oxide are reacted in a reactor to form a gas consisting essentially of carbon monoxide and zinc. The zinc is separated and reoxidized in a zinc oxidizer. In the reactor and the zinc oxidizer, heat exchange means are provided for that are connected to each other to form a heat exchange loop through which a heat exchange fluid is circulated such as to supply heat generated in the zinc oxidizer to the reactor.

Abstract: A process for thermally treating fine-grained solids with high-oxygen gases at temperatures at which the solids can form molten and gaseous reaction products comprises carrying out the thermal treatment at least in part in a cyclone chamber. The solids, high-oxygen gases and, if desired, an energy carrier (usually a carbon-containing solid, liquid or gas) are mixed to form a suspension at a temperature below the reaction temperature. The suspension is fed to a vertical combustion path (tube) and reacts therein to form another suspension of primarily molten particles which is admitted to the cyclone chamber. Reactants are added to the gas phase within a core-flow region of the cyclone chamber and/or immediately after the discharge of gas therefrom to a cooling chamber.