In producing titanium oxide containing rutile-type crystals by adding hydrochloric acid to an aqueous dispersion of an alkali metal titanate, sulfurous acid, disulfurous acid, sulfuric acid or a salt thereof is added. Thus, there is provided a titanium oxide powder which is doped with bivalent sulfur atoms (S.sup.2−) and in which a ratio (I.sub.A/I.sub.R) of a peak intensity (I.sub.A) of anatase-type crystals to a peak intensity (I.sub.R) of rutile-type crystals as measured by X-ray diffractometry is 0.1 or less. Moreover, a cosmetic is provided by dispersing the titanium oxide powder in a dispersion medium. Thus, bluish color derived from Rayleigh scattering is negated, providing a dispersion, particularly a cosmetic, with excellent transparency and color tone.

Provided are a self-cleaning coating, a self-cleaning fiber, a self-cleaning carpet and uses thereof. The self-cleaning coating is provided with a porous structure where pores communicate with one another; the volume of the pores comprised in the coating makes up 20%-98% of the total volume of the coating; and the pore diameter of the pores in the porous structure is between 0.5 nm-50 nm. The self-cleaning coating is mainly prepared from host materials; the host materials are one or more of titanium oxide, zirconia, titanium nitride, silicon oxide, tungsten oxide, g-C.sub.3N.sub.4 semiconducting polymer, perovskite semiconductor, silver, iron, gold, aluminum, copper, zinc, tin and platinum.

The present disclosure relates to methods of preparing sols of titanium dioxide nanoparticles that are photoactive, neutral, and in a substantially concentrated form. The methods particularly provide for concentrated sols in light of washing and dewatering under low cation concentrations and utilizing rapid peptizing through addition of the filter case to the peptizing agent. Concentrated acid may be utilized to maintain high TiO.sub.2 concentration while still avoiding precipitation of the colloidal TiO.sub.2. Concentrated photoactive, neutral titanium dioxide sols are also provided as well as compositions thereof and photoactive coatings formed therewith.

Digestion of impure alumina with sulfuric acid dissolves all constituents except silica. Resulting sulfates, produced from contaminants in the impure alumina, remain in solution at approximately 90 C. Hot filtration separates silica. Solution flow over metallic iron reduces ferric sulfate to ferrous sulfate. Controlled ammonia addition promotes hydrolysis and precipitation of hydrated titania from titanyl sulfate that is removed by filtration. Addition of ammonium sulfate forms ferrous ammonium sulfate and ammonium aluminum sulfate solutions. Alum is preferentially separated by crystallization. Addition of ammonium bicarbonate to ammonium alum solution precipitates ammonium aluminum carbonate which may be heated to produce alumina, ammonia, and carbon dioxide. The remaining iron rich liquor also contains magnesium sulfate. Addition of oxalic acid generates insoluble ferrous oxalate which is thermally decomposed to ferrous oxide. Carbon monoxide reduces the ferrous oxide to metallic iron. Further oxalic acid addition precipitates magnesium oxalate which is thermally decomposed to magnesium oxide.

The method in the disclosure is achieved by chemically reacting diluted sulfuric acid generated when industrial sulfate titanium white powder production with a titanium raw material, and controlling an acid/titanium ratio and an iron/titanium ratio so as to produce the nano catalytic wastewater treatment agent. When being used for treatment of dyeing wastewater and other alkaline wastewater, by virtue of alkaline and dilution environment in wastewater, the nano catalytic wastewater treatment agent is subjected to self-fitting hydrolysist to produce a new ecological nano titanium dioxide ultrafine particle as a catalyst for decomposing organic matters in wastewater so as to decompose the organic matters into carbon dioxide and water; a decomposed and oxidized hydrated iron compound is used as a flocculation and adsorption nano particle, achieving the purpose of removing organic matters in wastewater.

The method in the disclosure is achieved by chemically reacting diluted sulfuric acid generated when industrial sulfate titanium white powder production with a titanium raw material, and controlling an acid/titanium ratio and an iron/titanium ratio so as to produce the nano catalytic wastewater treatment agent. When being used for treatment of dyeing wastewater and other alkaline wastewater, by virtue of alkaline and dilution environment in wastewater, the nano catalytic wastewater treatment agent is subjected to self-fitting hydrolysist to produce a new ecological nano titanium dioxide ultrafine particle as a catalyst for decomposing organic matters in wastewater so as to decompose the organic matters into carbon dioxide and water; a decomposed and oxidized hydrated iron compound is used as a flocculation and adsorption nano particle, achieving the purpose of removing organic matters in wastewater.

The present invention provides titania particles which are formed by providing a titania sol and spray drying the titania sol. A morphology of the dried titania particles is controlled by producing the titania sol from a TiO.sub.2 containing slurry and controlling the pH of the slurry to be 3 pH units or more from the iso-electric point of the titania by adding a peptizing agent to reduce an extent to which the titania sol is flocculated, or by producing the titania sol from a TiO.sub.2 containing slurry and adjusting the iso-electric point to be 3 pH units or more from the pH of the slurry by adding a dispersant to reduce an extent to which the titania sol is flocculated. The titania particles have a continuous exterior convex surface, a diameter of 30 m or less, a BET specific surface area of 50 m.sup.2/g or more, and are porous.

Titanium oxide particles of the present invention include octahedral-shaped particles, in which each particle of the octahedral-shaped particles has line segments each of which connects two apexes which face each other and has a maximum value of the line segments, an average value of the maximum values is 300 nm or more and 1,000 nm or less, and a value (the average value of the maximum values/BET-converted average particle diameter) obtained by dividing the average value of the maximum values of the line segments by an average particle diameter converted from a BET specific surface area is 1.0 or more and 2.5 or less.

The present invention provides a linear porous titanium dioxide material and the preparation and products thereof. The linear porous titanium dioxide material has an anatase phase structure and a single crystal structure, and the structure of the linear porous titanium dioxide material is composed of a plurality of particles having an oriented growth direction. The invention also provides a method of preparing the above material and the use thereof. The long axis of structure of the titanium dioxide porous nanowire of the present invention facilitates effective electron migration.

The invention relates to a process for extracting metals and salts from titanium-bearing minerals such as perovskite. More particularly, although not exclusively, the invention relates to extracting titanium dioxide and optionally other compounds from melter slag derived from an iron-making process.