Abstract: Processes for the efficient and economical beneficiation of titaniferous ore are provided. A unique process for beneficiating ore comprising pretreatment of the ore by oxidation and reduction, followed by acid leaching with sulfuric acid has been developed. The acid used in this process may be recycled, which will thereby increase the efficiency of the process. Preferably the ore treated according to the present invention is ilmenite ore.

Abstract: A process and apparatus for the synthesis of metal oxide nanopowder from a metal compound vapour is presented. In particular a process and apparatus for the synthesis of TiO2 nanopowder from TiCl4 is disclosed. The metal compound vapour is reacted with an oxidizing gas in electrically induced RF frequency plasma thus forming a metal oxide vapour. The metal oxide vapour is rapidly cooled using a highly turbulent gas quench zone which quickly halts the particle growth process, yielding a substantial reduction in the size of metal oxide particles formed compared with known processes. The metal compound vapour can also react with a doping agent to create a doped metal oxide nanopowder. Additionally, a process and apparatus for the inline synthesis of a coated metal oxide is disclosed wherein the metal oxide particles are coated with a surface agent after being cooled in a highly turbulent gas quench zone.

Abstract: Titanium dioxide-calcium carbonate composite particles capable of realizing characteristic properties inherent in titanium dioxide such as a high opacity, a process for producing the same, and a complex composition or complex incorporated with the same are provided. The composite particles were prepared by adding titanium dioxide particles having an average particle diameter of 0.1 to 0.5 ?m in a carbonation step, typically a step of introducing a gaseous mixture of carbon dioxide and air into a calcium hydroxide slurry with stirring, to conduct a carbonation, and continuing the reaction till pH of the slurry becomes 7 by continuous introduction of the gaseous mixture. Moreover, by incorporating the formed composite particles, complexes such as coatings and paints for paper making or composite materials such as paper, plastic molded materials, and rubber molded materials are produced.

Abstract: The invention relates to a composite material comprising silicon and titanium dioxide characterized by an enhanced thermal and hydrothermal stability of the pore structure. The composite is obtainable by precipitating titanium hydroxide from an aqueous solution containing sulfate salts and urea, followed by an hydrothermal treatment in the mother liquor, and by reacting the precipitate with a basic silica sol. The composite has a specific surface area of up to 228 m2/g for a material calcined at 800° C. for 3 hours, and is suitable for catalyzing a variety of reactions, including Claus reaction and degradation of organic impurities.

Abstract: A method for producing a surface-activated crystalline titanium oxide product having a high adsorptive capacity and a high rate of adsorption with respect to dissolved contaminants includes the steps of preparing a titanium oxide precipitate from a mixture comprising a hydrolysable titanium compound and heating the precipitate at a temperature of less than 300° C., without calcining the precipitate. Preferably, the titanium oxide product includes crystalline anatase having primary crystallite diameters in the range of 1-30 nm. The surface-activated crystalline titanium oxide product is used in methods to remove dissolved inorganic contaminants from dilute aqueous streams by suspending the product in an aqueous stream or by filtering an aqueous stream through a bed of the product. In another method, a hydrolysable titanium compound is added to an aqueous stream so that titanium oxides form as a co-precipitate with dissolved contaminants within a bed of particulate material.

Abstract: The invention concerns the use of a film-forming titanium dioxide dispersion for cleaning and disinfecting surfaces exposed to light, by depositing a film of titanium dioxide nanoparticles on said surfaces, the continuous phase of said dispersion comprising water and/or at least an alcohol with boiling point at less than 120° C., said dispersion having, when it comprises water, a pH different by at least 1 unit of the value of the titanium dioxide isoelectric pH in said dispersion. The invention also concerns a film-forming titanium dioxide dispersion further comprises a film-forming polymer. The invention further concerns a method for cleaning and disinfecting surfaces exposed to light which consists in depositing and then drying on said surfaces a titanium oxide film-forming dispersion.

Abstract: The present invention provides a method for producing a ceramic dispersion composition, the method comprising the step of heating a mixture of a ceramic powder having a photocatalytic activity, a dispersant and a solvent at a temperature of about 70° C. or higher without substantially letting the solvent out of the reaction system. The ceramic dispersion composition can be used for providing a film showing a high hydrophilicity by light irradiation.

Abstract: A method for manufacturing single crystal ceramic powder is provided. The method includes a powder supply step for supplying powder consisting essentially of ceramic ingredients to a heat treatment area with a carrier gas, a heat treatment step for heating the powder supplied to the heat treatment area at temperatures required for single-crystallization of the powder to form a product, and a cooling step for cooling the product obtained in the heat treatment step to form single crystal ceramic powder. The method provides single crystal ceramic powder consisting of particles with a very small particle size and a sphericity being 0.9 or higher.

Abstract: A UV screening composition comprising particles which are capable of absorbing UV light so that electrons and positively charged holes are formed within the particles, characterised in that the particles are adapted to minimise migration to the surface of the particles of the electrons and/or the positively charged holes when said particles are exposed to UV light in an aqueous environment.

Abstract: Composites of ceramic materials, notably alumina or metal oxides in general, with single-wall carbon nanotubes are consolidated by electric field-assisted sintering to achieve a fully dense material that has an unusually high fracture toughness compared to the ceramic alone, and also when compared to composites that contain multi-wall rather than single-wall carbon nanotubes, and when compared to composites that are sintered by methods that do not include exposure to an electric field.

Abstract: A catalyst of a water insoluble vanadyl sulfate or a complex catalyst, in which a specific oxide and a specific sulfate are combined to the water insoluble vanadyl sulfate are excellent not only in their activity, durability and SO2 resistance, not only in substantially no oxidization of SO2 to SO3 as in HCl resistant. Therefore, using this catalyst, a decomposition treatment of an organic halide(s) can be carried out with high efficiency and good stability. In particular, a efficient decomposition treatment of an organic halides(s) can be carried out also in the cases that dust is coexist; the gas to be treated contains SOX or HCl; or they generate in the decomposition area.

Abstract: High purity refractory metals, valve metals, refractory metal oxides, valve metal oxides, or alloys thereof suitable for a variety of electrical, optical and mill product/fabricated parts usages are produced from their respective oxides by metalothermic reduction of a solid or liquid form of such oxide using a reducing agent that establishes (after ignition) a highly exothermic reaction, the reaction preferably taking place in a continuously or step-wise moving oxide such as gravity fall with metal retrievable at the bottom and an oxide of the reducing agent being removable as a gas or in other convenient form and unreacted reducing agent derivatives being removable by leaching or like process.

Abstract: A method for producing nanoscale titanium dioxide particles which are coated with an oxide, a hydroxide or an oxide hydroxide of Al, Ce, Zr and/or Si wherein the enzymatic precipitant system urease/urea is used. Said coated titanium dioxide particles can have an average size of less than 50 nm, the coating providing effective protection against photocatalytic reactions. The coated particles are suitable, in particular, as UV absorbers in a transparent organic matrix.

Abstract: A visible light responsive type material characterized in that said material is titanium oxide comprising at least anatase type titanium oxide, as well as in that a main signal having a g value ranging from 2.004 to 2.007 and two subsignals having a g value ranging from 1.985 to 1.986 and a g value at 2.024 are observed in the ESR measured under the irradiation of light having a wavelength of 420 nm or more at 77 K in vacuum, and said three signals are observed in a little amount or substantially not observed in darkness at 77 K in vacuum. A method of manufacturing a visible light responsive type material characterized in that amorphous or incomplete crystalline titanium oxide and/or titanium hydroxide (referred to as starting material titanium compound) are heated in the presence of ammonia or a derivative thereof, and said heating is stopped at the time when the light absorption at 450 nm of a material produced is larger than the light absorption at 450 nm of the starting material titanium compound.

Abstract: A titanium oxide showing sufficiently high photocatalytic activities by irradiation of visible light is provided. Using the titanium oxide, an excellent photocatalyst and photocatalyst coating composition is also provided. The titanium oxide has (i) three or more peaks within the range of from 1.930 to 2.030 in g value of electron spin resonance spectrum of the titanium oxide, wherein the largest one of the peaks is within the range of from 1.990 to 2.020 in the g value and/or (ii) a spin concentration X of 1.50×1016 spins/g or more, which is determined from electron spin resonance spectrum of the titanium oxide measured after irradiation of visible light.

Abstract: A process for producing a titanium oxide is provided which comprises (i) a step of calcining a titanium compound in the presence of ammonia gas or (ii) steps of treating a titanium compound with heat in the presence of ammonia gas and calcining the heat-treated titanium compound. The titanium oxide obtained in the present invention exhibits a sufficiently high photocatalytic activity by irradiation of visible light.

Abstract: A metal oxide powder except &agr;-alumina, comprising polyhedral particles having at least 6 planes each, a number average particle size of from 0.1 to 300 &mgr;m, and a D90/D10 ratio of 10 or less where D10 and D90 are particle sizes at 10% and 90% accumulation, respectively from the smallest particle size side in a cumulative particle size curve of the particles. This metal oxide powder contains less agglomerated particles, and has a narrow particle size distribution and a uniform particle shape.

Abstract: This invention pertains to the composition and method for fabricating nano-tube compositepolymer electrolyte. The composite polymer electrolyte is made by blending suitable amount of highly dispersed, nano-tube, such as titanium dioxide (TiO2), with highly amorphous polymer electrolyte, such as polyethylene oxide. The hollow nano-tube structure facilitates salt dissociation, serves temporarily storage for lithium ions, creates new conducting mechanism and improves the conductivity thereof. The subsequent thermal treatment and high electric field arrange the nano-tubes in order for increase of the dielectric constant thereof, which increased ion mobility at room temperature. The mechanical properties are also improved due to the physical cross-linking of the nano-tubes, suitable for industrial processing.

Abstract: A process is disclosed for forming a nanosize ceramic powder. A precursor ceramic material is formed of a fugitive constituent and a non-soluble constituent in a single phase. The precursor is contacted with a selective solvent (water, acid, etc.) to form a solution of the fugitive constituent in the solvent and a residue of the non-soluble constituent. The precursor is sufficiently reactive with the solvent to form the solution of the fugitive constituent in the solvent and form the nondissolved residue of the non-soluble constituent. The precursor material and the non-soluble residue are sufficiently insoluble in the solvent such that there is insufficient precursor material and non-soluble residue in solution to deposit and precipitate upon the residue of the non-soluble-constituent.

Abstract: A photocatalytic material having titanium oxide crystals and anions X incorporated therein, which is prepared by at least one of a method comprising substituting anions X for some of the oxygen sites of titanium oxide crystals, a method comprising doping anions X between lattices of a titanium crystal and a method comprising doping grain boundaries of titanium oxide, or a combination of these method. The photocatalytic material has acquired a new energy level formed in a band gap of titanium oxide, which results in its exhibition of a photocatalytic activity by absorbing visible lights. The photocatalytic material can thus exhibit a satisfactory photocatalytic activity under sunlight and also in a room with a fluorescent lamp.

Abstract: The invention relates to a process for the purification of titania by treating the titania with an aqueous solution comprising one or more ammonium compounds at elevated temperatures, separating the titania from the aqueous solution, drying the titania and, optionally, calcination of the dried titania. More especially the invention relates to the removal of sulphur (mainly present in the form of sulphate compounds) from the titania. The titania purified according to the above process is especially suitable for the use as catalyst carrier.

Abstract: The invention relates to a rutile titanium dioxide base material characterised by a lithium content of 0,05% to 0,5% by weight (calculated as Li2 referred to TiO2) and an aluminium content of 0,1% to 0,8% by weight (calculated as Al2O3 referred to TiO2.

Abstract: A method of producing fine particles of an oxide of a metal, comprising the steps of: preparing an acidic solution which contains ions of the metal; precipitating fine particles of a hydroxide of the metal by adding an alkaline solution to the acidic solution; collecting the fine particles of the hydroxide of the metal precipitated in a mixed solution of the acidic solution and the alkaline solution; mixing fine particles of a carbon with the collected fine particles of the hydroxide of the metal; and heat-treating a mixture of the fine particles of the hydroxide of the metal and the fine particles of the carbon at a predetermined temperature in a non-reducing atmosphere, whereby the fine particles of the oxide of the metal are produced.

Abstract: Microporous titanium dioxide particles having a crystalline structure and having an apparent density of less than 1.9 g/cm3.

Abstract: Organic molecules are partially oxidized in that the gas phase on supported and immobilized photocatalysts deposited having a nanostructure. the photocatalysts are semiconductors such as titanium dioxide and are preferentially coated onto a substrate by flame aerosol coating.

Abstract: A method for producing an anatase type titanium dioxide powder which comprises subjecting a titania sol, a titania gel or a titania sol-gel mixture to a heat treatment and simultaneously to a pressure treatment in a closed vessel, and subsequently drying the resulting product; and a method for producing an anatase type titanium dioxide slurry which comprises subjecting a titania sol, a titania gel or a titania sol-gel mixture to a heat treatment and simultaneously to a pressure treatment in a closed vessel, and subsequently agitating the resulting product to provide a dispersion. This method can be used for producing an anatase type titanium dioxide powder which exhibits high photocatalytic activity and has a large specific surface area, and an anatase type titanium dioxide slurry which has high storage stability and high dispersibility in a process operated at a relatively low temperature and having a small number of steps.

Abstract: A method of recovering titanium dioxide from a titanium oxide bearing raw material, such as e.g. steel slags rich in TiO2 includes the steps of grinding the titanium dioxide raw material, reacting the particulate raw feed material with sulphuric acid under specified conditions, digesting and filtering the resultant cake material containing titanyl sulphate, hydrolysing the titanyl sulphate and, after washing the hydrolysate, calcining the hydrolysate to produce titanium dioxide.

Abstract: The present invention relates to a single step process for the synthesis of nanoparticles of phase pure ceramic oxides of a single or a multi-component system comprising one or more metal ions. The process comprises preparing a solution containing all the required metal ions in stoichiometric ratio by dissolving their respective soluble salts in an organic solvent or in water, preparing a precursor, adjusting the nitrate/ammonia content in the system, and heating the system.

Abstract: The present invention provides a method for producing a titanium oxide. The method can be applied to produce a titanium oxide having a large specific surface area. The method typically entails calcinating at least one titanium oxide precursor selected from a titanium hydroxide and titanium peroxide, wherein the calcination occurs in the presence of nitrogen and at a steam pressure of at most about 8,000 Pa.

Abstract: An object of the present invention is to provide a photocatalytic powder containing titanium dioxide fine particles containing an anionically active substance, where the electrokinetic potential of the fine particle is from about −100 to 0 mV in an aqueous environment at pH 5. Another object of the present invention is to provide a photocatalytic slurry containing the powder, and a polymer composition, a coating agent, a photocatalytic functional molded article and a photocatalytic functional structure using the powder.

Abstract: A process for producing a titanium oxide is provided which comprises the steps of (i) mixing an acidic solution of a titanium compound with a nitrogen-containing basic organic compound to obtain a reaction product and (ii) calcining the obtained product. The titanium oxide exhibits a high photocatalytic activity by visible light radiation.

Abstract: A Ti—O—N film is formed on an SiO2 substrate by sputtering. For example, TiO2 is used as a target and nitrogen gas is introduced into the atmosphere. Crystallization is carried out by a post-sputtering heat treatment. Then a charge separation material such as Pt is supported on the Ti—O—N film. With the fabricated TiO2 crystals, the Ti—O—N film containing nitrogen exhibits a good catalytic reaction by using visible light as acting light. Since the charge separation material captures electrons or positive holes, recombination of electrons and positive holes is effectively prevented, and consequently more efficient photocatalytic reaction is performed. It is preferable to form a photocatalyst material film (Ti—Cr—O—N film) by sputtering the SiO2 substrate by use of TiO2 and Cr as the target in a nitrogen atmosphere. Crystallization is performed by a post-sputtering heat treatment.

Abstract: Anatase titanium dioxide particles with a size of at most 100 nm wherein the particles are at least partially covered with a layer of at least one metal oxide, hydroxide or hydroxide oxide and the particles exhibit a BET specific surface of at least 70 m2/g and a relative density of the order of 2.2. A process for preparing the anatase dioxide particles is also disclosed.

Abstract: Porous ceramics are described, which are produced by a) mixing an aqueous solution of a suitable ionotropically orientable polyanion, either with oxides, hydroxides or hydrated oxides, which are present in the form of a sol, of the metals Al, Zr, Ti and Nb, or with finely crystalline oxides, hydroxides or hydrated oxides, which are present in suspension, of these metals, or with finely crystalline tricalcium phosphate or apatite which are present in suspension, b) bringing the mixed sol obtained as in a) or the suspension obtained as in a) into contact with a solution of a salt of a di- or trivalent metal cation in order to produce an ionotropic gel body, c) compacting the gel body by introducing it into electrolyte solutions which further enhance the syneresis of the polyelectrolyte which was originally formed, d) washing the gel body with water and subsequently impregnating it with a readily volatile, water-miscible solvent, e) freeing the anhydrous gel body or gel bodies obtained as in d) from the

Abstract: The present invention is directed to photocatalytically active rutile titanium dioxide. The photocatalytically active rutile titanium dioxide of the present invention demonstrates enhanced activity in the visible light spectrum. It may be produced by neutralizing rutile seed to a higher pH than that at which it has traditionally been neutralized prior to washing and thermally treating the seed.

Abstract: A photocatalyst is provided, which comprises a titanium oxide and a metal-containing compound other than titanium oxide on the surface of the titanium oxide, wherein the metal-containing compound is a metal oxide having an acid site and the photocatalyst has a BET specific surface area of about 55 m2/g or larger, or wherein the metal-containing compound is a basic metal-containing compound and the photocatalyst has an anatase-crystalline structure and an anatase-crystalline size of about 10 nm or larger. The photocatalyst shows sufficiently high photocatalytic activities by irradiation of visible light.

Abstract: Process for the preparation of articles in Titanium coated with a layer of Titanium oxide is described, wherein the metallic Titanium is subjected to the following steps: optional conditioning of the surface; anodic oxidation treatment, in an electrolytic cell of which it represents the anode, in a bath made of an aqueous solution comprising sulfuric acid, hydrochloric acid and hydrofluoric acid; and forming onto the metallic surface, by effect of electrolysis, an oxide layer having a >1 &mgr;m thickness and containing a single crystalline phase made of anatase (one of the two allotropic tetragonal shapes of Titanium oxide). Object of the invention are also the articles in Titanium coated with a thick layer of anatase so obtainable, and the use thereof as photocatalysts, under the action of an ultraviolet radiation.

Abstract: A process for producing a titanium oxide is provided which comprises the steps of (i) reacting a titanium compound with ammonia in an amount exceeding the stoichiometric amount necessary to convert the titanium compound to a titanium hydroxide or reacting a titanium compound with a base at pH of from about 2 to about 7, to obtain a reaction product and (ii) calcining the obtained product. The titanium oxide exhibits a high photocatalytic activity by visible light radiation.

Abstract: A reactor 20 has a plurality of tubular downcomers 32, 34, 36, 38, 40 and risers 42, 44, 46, 48, 50, joined by sections 86, 88 in a continuous serpentine path the tubes dimensioned to provide substantially plug flow conditions for solid and liquid reagents fed into a first downcomer 24 with the products extracted from final riser 52. The reactor 20 is designed for a desired residence time by the number, height and diameter of the tubes. The downcomers 24, 32, 34, 36, 38, 40 may include a bend to improve residence time and to thereby reduce the number of tubes required for a desired overall residence time. The reactor 20 can be used in a leaching operation for producing synthetic rutile, where a pre-treated feedstock including ilmenite, leueoxene or titania slag is leached with hot HCl.

Abstract: Improved photovoltaic cells utilizing for a semiconductor layer, titanium dioxide powders, consisting of porous particles, ranging in size from 0.1 to 10 microns (10−6 meters), and possess relatively high bulk density combined with high surface area.

Abstract: A titanium dioxide compound was isolated from a rare type of naturally occurring ore. Processes for efficiently isolating and obtaining these TiO2 compounds, as well as methods for using them have been developed. These TiO2 compounds may be used directly in applications such as paper, plastics and paints without being subjected to the chloride or sulfate processes. Also they made be used as a feedstock for the chloride or sulfate processes. In order to obtain these TiO2 compounds, one may grind or pulverize the naturally occurring ore, disperse it in a solution or suspension, and process it by selective flocculation or aqueous biphasic extraction.

Abstract: An electroconductive plate-like titania containing at least 10% by weight of titanium nitride and at least 0.1% by weight of carbon component can provide electroconductive parts which are higher and more uniform in electroconductivity.

Abstract: Improved methods for producing titanium dioxide slurries. The output from a micronizer is passed through a condenser to condense the steam and form an aqueous slurry of titanium dioxide, which can in most cases then be further concentrated as desired or which can be sold or used without further concentration, instead of passing the micronizer output to apparatus for separating the TiO2 from the steam, as is currently practiced in the art. The resultant slurry from the condenser is in a further refinement preferably sent to an agitated storage tank together with dispersant and anti-settling compounds to aid in preventing settling of the titanium dioxide solids out of the slurry. To help facilitate condensation of the steam/pigment mixture sent to the condenser, a portion of the condensed slurry is in yet a further refinement pumped from the slurry storage tank to a heat exchanger. The output from the heat exchanger is then fed to the condenser to facilitate the condensing of the steam in the condenser.

Abstract: A process for producing a titanium oxide is provided which comprises (i) a step of calcining a titanium compound in the presence of ammonia gas or (ii) steps of treating a titanium compound with heat in the presence of ammonia gas and calcining the heat-treated titanium compound. The titanium oxide obtained in the present invention exhibits a sufficiently high photocatalytic activity by irradiation of visible light.

Abstract: Pickering emulsions, which are finely disperse systems of the water-in-oil or oil-in-water type, comprising (1) an oil phase which contains a wax and/or an oil thickener, (2) a water phase, (3) at least one type of microfine particles which a) have an average particle size of less than 200 nm, which b) display both hydrophilic and lipophilic properties, i.e. which have amphiphilic character, and are dispersible both in water and in oil and which c) have optionally been coated on the surface, (4) at least one type of non-amphiphilic metal oxide pigments and (5) at most 0.5% by weight of one or more emulsifiers.

Abstract: To provide a novel light responsive material having responsive property with visible light despite essentially not comprising oxygen defects, a method of manufacturing thereof, and applications thereof. That is, the light-responsive material in the form of rutile-type titanium oxide with a light source peak wavelength of 520 nm and activity due to the effect of light with a full width at half maximum of 20 nm. The activity due to the effect of light is NO elimination activity. The method of manufacturing the light-responsive material comprising the treatment with nitrogen plasma, or the treatment in an ammonia atmosphere of rutile-type titanium oxide.

Abstract: Mesoporous nanocrystalline titanium dioxide heterojunction materials and methods of making the same are disclosed. In one disclosed embodiment, materials comprising a core of titanium dioxide and a shell of a molybdenum oxide exhibit a decrease in their photoadsorption energy as the size of the titanium dioxide core decreases.

Abstract: Pyrogenically prepared titanium dioxide doped by means of an aerosol contains an oxide from the group zinc oxide, platinum oxide, magnesium oxide and/or aluminium oxide as the doping component. It is prepared as follows: in the pyrogenic preparation of titanium dioxide, a metal salt solution is atomised to form an aerosol and injected into the production stream. The titanium dioxide may be used as a photocatalyst or as a UV adsorber.

Abstract: The bodies are prepared either by pelleting of a pasty mixture of titanium dioxide powder and titanium dioxide sol and/or 1-20% nitric acid, followed by dehydration and calcination at a temperature of between 400 and 1000° C. for between 0.5 and 3.5 hours; or by preparing pellets from the titanium dioxide powder and added water, annealing of the pellets at between 300 and 500° C., saturation of same with titanium dioxide sol or 1-20% nitric acid in a vacuum, followed by drying and finally annealing at a temperature of between 400 and 1000° C. for between 0.5 and 3 hours.

Abstract: Nanoparticulate titanium dioxide coating produced by educing flocculates of titanium dioxide nanoparticles from a titanyl sulfate solution and dispersing the nanoparticles in a polar sol-forming medium to make a sol suitable as a coating usable to impart photocatalytic activity, U.V. screening properties, and fire retardency to particles and to surfaces. The photocatalytic material and activity is preferably localized in dispersed concentrated nanoparticles, spots or islands both to save costs and leverage anti-microbial effects.