Abstract: A process for the preparation of an improved quality TiO.sub.2 pigment by hydrolysis of titanyl sulphate, isolation of the hydrolysis product form the waste acid produced during the hydrolysis, washing of the hydrolysis product and calcination of the hydrolysis product to form the TiO.sub.2 pigment, wherein the hydrolysis of the titanyl sulphate is carried out using separately produced hydrolysis nuclei which have been produced by a reaction of titanium salts with alkaline reagents, and in which waste acid and/or wash liquid containing waste acid is added after at least 50% of the total duration of the hydrolysis process.

Abstract: The present invention includes metal oxide foam particles and a method of making the same. A decomposable metal salt feed solution is injected into a hot atomizing gas. The mixture of hot atomizing gas and feed solution is maintained in the reactor until the feed solution converts to metal oxide foam particles. The metal oxide foam particles have a high specific surface area.

Abstract: A synthetic rutile is prepared from a titaniferous slag, typically containing at least about 1.0 weight percent magnesium oxide and at least some portion of its titanium values as Ti.sub.2 O.sub.3, by a method comprising contacting the slag with chlorine gas at a temperature between about 400.degree. C.-800.degree. C., such that the magnesium oxide and chlorine gas react to form magnesium chloride, and then removing the magnesium chloride from the slag, typically by washing the slag with water. In one embodiment, the synthetic rutile can be further upgraded by subjecting it to either a caustic or acid leaching treatment.

Abstract: A process for the production of TiO.sub.2 pigments by the sulfate process by digestion of titanium-containing raw materials with sulfuric acid, hydrolysis of the titanyl sulfate formed, purification of the hydrolyzate and calcination of the hydrolyzate in rotary kilns, wherein the calcination conditions are regulated through adjustment of the SO.sub.2 content of the waste gases issuing from the rotary kilns used for calcination.

Abstract: A process for preparing high quality titanium dioxide which exhibits excellent reflectance and tint strength when incorporated into a coating formulation. The process involves the preparation of a seed solution wherein one of the seed curing factors of time, temperature and amount of alkaline neutralizing agent are varied to establish maximum reflectance and tint strength values obtained by the final product. The process can be repeated to analyze one or both of the other factors. The process can be used to prepare titanium dioxide in the anatase or rutile form and on a batch or continuous basis.

Abstract: Shaped titanium oxide catalysts/carriers useful, e.g., for sulfur recovery via Claus catalysis, are prepared by (i) intimately admixing powdered, poorly crystalline and/or amorphous titanium oxide, said titanium oxide powder being characterized by a weight loss on ignition ranging from 1 to 50%, water and from 0 to about 15% by weight of a shaping additive, (ii) next shaping the intimate admixture which results, and (iii) thence, optionally after drying, calcining the product shaped article.

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 novel titanium dioxide hydrate is provided whose structure exhibits X-ray diffraction peaks at 24.6.+-.0.4.degree. and 48.+-.0.4.degree., and which is suitable as an adsorbent material. A process for preparing the novel titanium dioxide hydrate also is provided which includes hydrolyzing a specific titanium sulfate solution and thereafter flocculating colloidal titanium dioxide hydrate by the addition of a monobasic acid and recovering the titanium dioxide hydrate.

Abstract: A polycrystalline, fibrous rutile TiO.sub.2 pigmentary material having good optical properties and retention in paper, and exceptionally high tinting strength in latex paint systems is prepared by treating a substantially sulfate-free hydrous TiO.sub.2, prior to calcination, with a mineralizing complex comprising alkali metal and alkaline earth metal salts, a compound of boron and a rutile promoter sol, and calcining the treated hydrous TiO.sub.2 at temperatures in the ranges of from 812.degree.-865.degree. C. followed by washing to remove the calcium ions, milling, hydroclassification and drying; or optionally by a postcalcination treatment for imparting optimum pigmentary properties.

Abstract: A solution of active nuclei for the hydrolysis of titanium sulphate and for the rutilisation of titanium dioxide in the manufacture of titanium dioxide in tutile form in the method via sulphate is prepared by transforming titanium tetrachloride into a compound of the formula Ti(OH).sub.x Cl.sub.y, wherein x ranges from 1 to 3, y from 3 to 1 and x + y is equal to 4 by contact with steam in the vapor phase, and contacting the reaction products with an aqueous solution of sodium hydroxide to form an aqueous suspension of titanium hydroxide having a TiO.sub.2 content of from 10 to 30 grams/liter and a pH value of from 3 to 4.

Abstract: In the production of a solid-free solution of titanyl sulfate by digesting ilmenite or titanium slag with sulfuric acid, and filtering the resulting solid-containing solution of titanyl sulfate to separate the solids, the improvement which comprises filtering the solution under a pressure of about 1 to 16 bars to form a filter cake of a thickness of about 10 to 35 mm. The filter cake is washed with about 0.1 to 0.5 m.sup.3 of water per m.sup.3 of filtrate, the wash water is passed through the filter cake at a flow rate of about 0.1 to 1.2 m/h under a pressure of about 1 to 16 bars, and the filter cake is then squeezed to a solid content of about 50 to 70% by weight.

Abstract: A process for the joint production of titanium dioxide and sodium tripolyphosphate from ores of titanium and phosphorus, and from sulphuric acid, in which the titanium dioxide is produced by the "sulphate process" and the impure dilute aqueous solution of sulphuric acid resulting therefrom is concentrated and used in the initial attack of phosphatic ones to provide a solution containing vanadium and chromium which can be removed without requiring any preventive conversion. The resulting sodium phosphate is then converted to sodium tripolyphosphate in a known way.

Abstract: In the recovery of titanium dioxide by subjecting an aqueous titanium dioxide hydrate suspension to at least one stage of filtering and washing to form a washed filter cake, adjusting the composition and calcining the adjusted and washed filter cake, the improvement which comprises filtering the aqueous titanium dioxide hydrate suspension under a pressure of about 1 bar to 16 bars to form a homogeneous substantially crack-free filter cake of a thickness of about 10 to 25 mm. Advantageously a membrane filter is employed, and washing is effected under a pressure of 1 to 16 bars and a liquid flow rate of 0.1 to 1 m/h to produce a filter cake having a solids content of at least 45 % by weight.