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Invention relates to composition, based on oxides of zirconium, cerium and at least one rare earth metal element, different from cerium, to method of its obtaining and to its application for purification of exhaust gases of internal combustion engines. Composition, based on oxides of zirconium, cerium and at least one rare earth metal element, different from cerium, contains cerium oxide not more than 50 wt % and has after burning at 1000°C for 6 hours maximal temperature of reductability not more than 500°C and specific surface at least 45 m2/g. method of obtaining composition includes carrying out continuous reaction in mixture of compounds of zirconium, cerium and other rare earth metal element, different from cerium with basic compound with time of being in reactor not longer than 100 milliseconds, obtained sediment is heated, and then combined with surface-active substance before burning Catalytic system, containing claimed composition, and method of purification of exhaust gases of internal combustion engines with application of described above composition or catalytic system as catalyst, are described. |
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Zirconium oxide dispersion, method for production thereof and resin composition containing same Invention can be used in chemical industry. The zirconium oxide dispersion is obtained by reacting a zirconium salt with an alkali in water to obtain a suspension of zirconium oxide particles. The suspension is filtered, washed and repulped. An organic acid is added to the obtained suspension in amount of one molar part or more per molar part of zirconium in the suspension and the suspension is subjected to hydrothermal treatment at temperature of 170°C or higher. The obtained aqueous dispersion of zirconium oxide particles is then washed and thickened. The zirconium oxide dispersion contains zirconium oxide particles in amount of 20 wt % or more, has low viscosity and is characterised by a transmittance factor of 35% or more at wavelength of 400 nm, transmittance factor of 95% or more at wavelength of 800 nm and viscosity of 20 mPa·s or less at temperature of 25°C. |
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Method of producing nanopowder zirconium, yttrium and titanium composite oxide Invention can be used in production of dense wear-resistant ceramic and solid electrolytes. The method of producing powder of a zirconium, yttrium and titanium composite oxide involves preparing a starting solution of nitrates, adding an organic acid and a titanium-containing compound into said solution, followed by heat treatment. The organic acid used is glycine in amount of 1.6-2.5 mol per 1 g-atom of the sum of metal cations (Zr+4+Ti+4+Y+3). The titanium-containing compound used is a hydrolysable titanium compound with the ratio Zr+4:Ti+4=(0.99-0.85):(0.15-0.01). The starting solution is further mixed with 30% hydrogen peroxide with the ratio H2O2:Ti+4=(4.7-12):1. The hydrolysable titanium compound used can be titanium tetrabutylate or titanium sulphate or titanium tetrachloride. |
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Invention relates to a composition based on cerium oxide and zirconium oxide having special porosity, which can be used in catalyst systems for treating exhaust gases. The composition is based on cerium oxide and zirconium oxide containing at least 30 wt % cerium oxide which, after calcination at temperature of 900°C for 4 hours, has two types of pore distribution, the diameters of which, for the first type of distribution, lie in the range from 5 nm to 15 nm for a composition having cerium oxide content of 30% to 65%, or from 10 nm to 20 nm for a composition having cerium oxide content higher than 65% and, for the second type of distribution, in the range from 45 nm to 65 nm for a composition having a cerium oxide content of 30% to 65% or from 60 nm to 100 nm for a composition having cerium oxide content higher than 65%. The method of producing the composition includes steps of: forming a first liquid medium containing a zirconium compound, a cerium (III) compound, sulphate ions, an oxidising agent and, optimally, a compound of a rare-earth element other than cerium; bringing the medium into contact with a base, whereby a precipitate is formed; separating and washing the precipitate; suspending the precipitate in water and heat treatment of the obtained medium at temperature of 90°C; and separating and calcining the precipitate. |
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Composition based on complex oxides of zirconium, phosphorus and calcium for coating obtaining Invention can be used in chemical industry. Composition for obtaining thin film of complex oxides of zirconium, phosphorus and calcium contains ethyl alcohol, preliminarily distilled and dried to 96 wt %, zirconium oxochloride, calcium chloride and orthophosphoric acid with the following component ratio, wt %: zirconium oxochloride - 4.7-6.8; calcium chloride - 2.6-4.4; orthophosphoric acid - 0.5, ethyl alcohol - the remaining part. |
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Invention relates to a method of producing nanoparticles of a transition metal oxide coated with amorphous carbon. A liquid mixture containing as precursors at least one alkoxide of a transition metal selected from Ti, Zr, Hf, V, Nb and Ta, an alcohol and excess acetic acid with respect to the transition metal is diluted with water to obtain an aqueous solution. Precursors are contained in the solution in a molar ratio which is sufficient to prevent or significantly limit sol formation. The transition metal, carbon and oxygen are contained in said solution in a stoichiometric ratio which corresponds to the composition of nanoparticles. The aqueous solution is freeze-dried and the freeze-dried product undergoes pyrolysis in a vacuum or an inert atmosphere to obtain nanoparticles. The obtained nanoparticles can be subjected to carbothermal reduction to obtain carbide nanoparticles. |
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Invention relates to field of chemistry, in particular, to catalytic compositions, applied as catalyst. Claimed are catalytic composition, methods of its application and catalytic system. Catalytic system, which contains at least one oxide on carrier, selected from zirconium oxide, titanium oxide or mixed zirconium and titanium oxide, applied on aluminium oxide or aluminium oxyhydroxide carrier, and which has after burning at 900°C for 4 hours size of particles of oxide on carrier not larger than 10 nm, if oxide on carrier is obtained on zirconium oxide base or not larger than 15 nm, if oxide on carrier is obtained on the base of titanium oxide or mixed zirconium and titanium oxide. Catalytic system contains claimed catalytic composition. |
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Filler and composite materials with zirconium and silica nanoparticles Invention relates to filler materials made of nanoparticles for use in composite materials, including dental composite materials. The filler materials contain clusters of silica and zirconium dioxide nanoparticles. The filler materials can be obtained by mixing a sol of silica nanoparticles with a sol of pre-formed crystalline particles of zirconium nano-oxide. |
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Method of processing zirconium tetrachloride to obtain zirconium dioxide and hydrochloric acid Invention relates to methods of processing zirconium tetrachloride and can be used in chlorine metallurgy when producing zirconium dioxide and hydrochloric acid. The method involves mixing zirconium tetrachloride with water in molar ratio ZrCL4:H2O=1:(1.0-1.2), obtaining zirconium oxychloride and hydrogen chloride gas, dissolving zirconium oxychloride in water, adding sulphuric acid with distillation of the HCl-H2O azeotropic mixture and precipitation of basic zirconium sulphate, filtering the suspension, washing and calcining the residue to obtain zirconium dioxide. Hydrogen chloride gas formed when producing zirconium oxychloride is taken for absorption, where the absorbent used is the HCl-H2O azeotropic mixture obtained during precipitation of basic zirconium sulphate. Concentrated hydrochloric obtained from absorption can be used in non-ferrous metallurgy when leaching concentrates and ores, etching metal surfaces of equipment, metal-roll and for other purposes. |
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Zircon concentrate processing method Method involves chlorination of zircon concentrate, separate condensation of chlorinates, cleaning of silicon and zirconium tetrachlorides, aqueous hydrolysis of zirconium tetrachloride and deposition of zirconyl sulphate with distillation of azeotropic HCl-H2O mixture, filtration, washing and calcination of deposition so that zirconium dioxide is obtained, high-temperature vapour-phase hydrolysis of silicon tetrachloride in hydrogen-air flame so that pyrogenic silicon dioxide and HCl-bearing exhaust gases are obtained; absorption of hydrogen chloride by using azeotropic HCl-H2O mixture as absorbent, which is formed during hydrolytic separation of zirconyl sulphate. |
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Invention can be used in inorganic chemistry. The catalytic composition contains at least one oxide on a support, which is based on zirconium oxide, titanium oxide or a mixed zirconium and titanium oxide, deposited on a silicon oxide-based support. After firing at 900°C for 4 hours, the oxide on the support has the form of particles deposited on a support and size of said particles is not greater than 5 nm if the oxide on the support is based on zirconium oxide, not greater than 10 nm if the oxide on the support is based on titanium oxide and not greater than 8 nm if the oxide on the support is based on a mixed zirconium and titanium oxide. After firing at 1000°C for 4 hours, particle size is not greater than 7 nm if the oxide on the support is based on zirconium oxide, not greater than 19 nm if the oxide on the support is based on titanium oxide and not greater than 10 nm if the oxide on the support is based on a mixed zirconium and titanium oxide. |
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Zirconium oxide and way of its production Invention refers to powdered zirconium oxide, way of its production and its application in fuel cells, notably for production of electrolyte substances for ceramic fuel cells. The powdered zirconium oxide containing up to 10 mole % of at least one metal oxide from the scandium, yttrium groups, the group of rare-earth elements and/or their mixtures is characterized by the extension density from 1.2 to 2.5 g/cm³ measured according to ASTM B 417. |
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Composition contains 1-20% yttrium oxide, 1-30% tungsten oxide and zirconium oxide - the rest. The specific surface area of the composition is at least equal to 20 m2/g after calcination for 4 hours at 900°C. |
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Invention relates to chemistry and can be used in catalytic processes. Amorphous zirconium hydroxide has surface area of at least 300 m2/g, total pore volume of at least 0.70 cm3/g and average pore size from 5 nm to 15 nm. First, an aqueous solution containing sulphate anions and a zirconium salt with the ratio ZrC2:SO3 ranging from 1:0.40 to 1:0.52 are obtained. The solution is then cooled to temperature lower than 25°C. Alkali is then added to precipitate amorphous zirconium hydroxide which is then filtered and washed with water or alkali to remove residual sulphate and chloride. The washed residue undergoes thermal treatment at excess pressure of not less than 3 bars and dried. |
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In order to obtain ground mineral material a) at least one mineral material which is optionally in form of aqueous suspension is taken, b) said material is ground, c) the ground material obtained at step (b) is optionally sieved and/or concentrated, d) the ground material obtained at step (b) or (c) is optionally dried. The grinding step (b) is carried out in the presence of zirconium oxide grinding beads containing cerium oxide, having cerium oxide content between 14 and 20% of the total weight of said beads, preferably between 15 and 18% of the total weight of said beads, and more preferably approximately 16% of the total weight of said beads. The average size of grains after sintering grains which form said beads with average diameter less than 1 mcm is preferably less than 0.5 mcm and more preferably less than 0.3 mcm. The obtained ground mineral material is in form of aqueous suspension, wherein the weight ratio ZrO2/CeO2 is equal to 4-6.5, preferably 4.6-5.7 and more preferably 5.3. |
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Method of producing nanocrystalline powder of metal oxides Method involves production of metal hydroxides via reverse precipitation, drying and calcination. To prevent local change in pH of the solution of the precipitation agent, the reverse precipitation method involves ultrasonic treatment of the solution of metal salts in an atomising nozzle through which the said solution passes before reacting with the solution of the precipitation agent. The solution of metal salts undergoes ultrasonic treatment which enables to disperse the solution to droplets with size smaller than 1.0 mcm. |
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Composition for making thin films based on system of double oxides of zirconium and zinc Invention relates to production of thin-film materials used in illumination, construction and electronics. The composition for making thin films based on a system of double oxides of zirconium and zinc contains the following components, wt %: zirconium oxochloride 4.0-8.6; zinc nitrate 3.8-7.6; pre-distilled and dried to 96 wt % ethyl alcohol - the rest. The film-forming solution of the said composition is deposited onto a substrate by centrifuging and subjected to step-by-step thermal treatment. |
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Method of obtaining nanodispersed metal oxides Invention can be used in production of refractory ceramic matrices of composite materials and high-temperature coatings. A solution of β-diketonates of one or more metals with concentration of 1·10-3-1 mol/l in an organic solvent or mixture of solvents in the presence of an alcohol undergoes thermal treatment at 95-250 °C for 0.1-8 hours to obtain solutions of alkoxo-β-diketones of corresponding metals. Hydrolysis is then carried out at 15-95°C for 0.05-240 hours with hydrolysing solutions, which are either water, organic solvents or mixture of solvents containing water or a mixture of organic solvents and water to form transparent gels. Further, the gels are dried at 15-250°C and pressure of 1·10-4-1 atm until constant weight. Thermal treatment of xerogels to form nanocrystalline metal oxides is carried out in an oxygen-containing atmosphere at 350-750°C for 0.5-24 hours. |
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Invention can be used for exhaust gas after burning in ICE. Aqueous mix containing zirconium and cesium and one of lanthanides, ether than cerium, and yttrium is obtained. Obtained mix is heated to 100 °C to produce precipitate in the form of suspension in reaction medium which is brought up to the level of alkaline pH. First, added is additive selected from anion surfactants, nonionic surfactants, polyethylene glycols, carbonic acids and their salts, and surfactants of the type of carboxymethylated oxethylates of fat alcohols is added to produced medium and, then precipitate is separated. In compliance with another version, first, precipitate is liberated from reaction medium and, thereafter, aforesaid additive is added to precipitate. Precipitate is calcinated in atmosphere of inert gas or in vacuum at 900 °C and, then in oxidising atmosphere at 600 °C. Produced composition contains cerium oxide in amount of not over 50 wt %. Reduction degree after calcination in atmosphere of air at 600 °C makes at least 95 %, while specific surface after calcination at 1100 °C for 4 h makes at least 15 m2/g. |
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Composition for making thin film based on system of double oxides of zirconium and titanium Invention can be used in electronic engineering, lighting and construction industry. The composition is obtained by preparing a film-forming solution based on 96 wt % ethyl alcohol, 6.68-10.02 wt % crystalline hydrate of zirconium oxochloride and 3.34-5.01 wt % tetraethoxytitanium. The obtained solution is deposited onto a substrate and thermally treated. |
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Method of preparing zirconium dioxide nanopowder Zirconium hydroxide is precipitated and then simultaneously dried and calcined under microwave radiation in the frequency range 50-20000 MHz with continuous power of 3.0-50.0 kW for 5-60 minutes. |
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Method of producing zirconium oxide having tetragonal modification for producing catalysts Invention relates to methods of producing zirconium oxide used in chemistry for producing catalysts. The invention describes a method of producing zirconium (IV) oxide for producing catalysts involving preparation of an initial reaction aqueous solution of a zirconium (IV) salt, precipitation of zirconium hydroxide from the solution, separation of the obtained zirconium hydroxide precipitate from the aqueous solution, drying and calcination of the precipitate at 600°C. The method is characterised by that precipitation is carried out using an anionite in OH form. |
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Zirconium-bearing raw material processing method Invention refers to processing of zirconium-bearing natural raw material, namely zirconium concentrate, and can be used for obtaining microdispersed high-purity zirconium dioxide. Processing method involves fluoridisation of zirconium-bearing raw material, heat treatment of fluoridised product so that zirconium tetrafluoride is obtained, and its further pyrohydrolysis. Fluoridisation is performed by treatment of zirconium-bearing raw material with 10-20% solution of hydrofluoric acid with conversion of zirconium compounds to the solution, separation of solution from the formed settlement, addition of ammonium fluoride to the obtained solution with further extraction of deposited fluoridisation product. Heat treatment of the extracted fluoridisation product so that zirconium tetrafluoride is obtained is performed by thermal decomposition at 600-650°C with separation of ammonium fluoride and removal of ammonium hexafluorosilicate by distillation. Pyrohydrolysis of zirconium tetrafluoride is performed in gas phase. |
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Method of producing hydrate of metal oxide Method of producing a hydrate of a metal oxide involves treatment of a metal salt with ammonia gas, separation of hydrate residue from the suspension with formation of a solution which contains an ammonium salt, washing the hydrate residue and drying. The metal salt used is an aluminium, titanium or zirconium salt in form of crystalline hydrates with particle size of 0.1 to 3.0 mm. Metal salts are treated with ammonia gas by passing ammonia gas through a layer of particles of crystalline hydrates until pH of aqueous extraction of the reaction mass of not less than 7. The obtained reaction mass is leached with water or a solution from washing the hydrate residue with formation of a suspension, from which the hydrate residue is separated. |
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Method of purifying baddeleyite concentrate Present invention relates to the method of purifying baddeleyite concentrate. The method involves treatment of baddeleyite with concentrated sulphuric acid while heating, obtaining a solid sulphatisation product, which is turned into pulp using water. Purified baddeleyite concentrate is gravitationally separated from the pulp. A hydrated residue is also separated from the sulphuric acid solution, containing rare elements and impurity components. The method is distinguished by that, the baddeleyite concentrate is subjected to pre-treatment with dilute 2-7% sulphuric or hydrochloric acid at temperature 40-60°C with transfer of part of impurity components into the solution and formation of a residue of baddeleyite concentrate, which is separated from the sulphuric acid or hydrochloric acid solution, washed with water and subjected to magnetic separation, obtaining pre-purified baddelyite concentrate. The concentrate is then treated with concentrated 93-96% sulphuric acid at temperature 180-200°C. After separation of the baddeleyite concentrate, the sulphuric acid solution is neutralised with lime milk. |
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Method of preparing zirconium oxides and zirconium based mixed oxides Present invention is meant for chemical and automobile industry and can be used in making promoters and catalyst carriers for automobile systems of releasing exhaust gases. Zirconium hydroxide is precipitated from an aqueous solution of a zirconium salt by an alkali in the presence of a controlled amount of sulphate anions at ratio SO4 2-/Zr4+ ranging from 0.3/1 to 1.5/1 and temperature not above 50°C. Sodium hydroxide can be used as the alkali. The aqueous solution can contain a salt of an alkaline, rare earth, transition metal, silicon, tin or lead, as well as their mixture. The hydroxide is calcinated, forming oxide, which practically does not contain sulphate. Specific surface area of the oxide after sintering at 1000°C is not less than 40 m2/g, and not less than 10 m2/g after sintering at 1100°C. |
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Method of brazilite concentrate extraction Invention refers to brazilite concentrate technology from zirconium waste with simultaneous liberation of rare-metal concentrate. Invention refers to method of brazilite concentrate extraction. Herewith raw materials are magnetic finish fraction of brazilite concentrate. Magnetic fraction is processed with 7-10% hydrochloric acid or 10-30% sulphuric acid at 60-90°C. Brazilite deposition is separated, washed, dried and followed with two-phase magnetic separation. The first stage includes magnetic separation in magnetic field of average intensity equal to 10000-14000 E and liberation of crude brazilite concentrate and average-magnetic delivered to spoil bank. The second stage includes separation of crude brazilite concentrate in high-intensity magnetic field 20000-24000 E and liberation of base of brazilite concentrate and low-magnetic fraction processed in high-temperature sulphuric acid medium. Low-magnetic fraction is processed with 85-93% sulphuric acid at 200-250°C in mass relation S:L=1:0.4-0.6. Produced sulphatisation product is pulped in water with derived pulp from which residue of brazilite concentrate is separated and sulphate suspension containing rare elements is produced. |
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Composition for obtaining thin film based on system of double zirconium and germanium oxides Composition for obtaining thin film based on system of double zirconium and germanium oxides includes following components, wt %: crystallohydrate of zirconium oxochloride ZrOCl2-8H2O - 3.8-9.0; germanium tetrachloride - 3.0-7.1; 96% ethyl alcohol - remaining part. |
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Method of brazilite concentrate purification Mixing of brazilite concentrate with concentrated sulphuric acid, its sulphatisation with heating, formation of pulp by processing sulphatisation product with liquid reagent, separating of brazilite from pulp are carried out; mixing of brazilite concentrate and suphuric acid is carried out with weight ratio of concentrate and acid respectively 1:(0.165-0.195) and concentration of sulphuric acid not less than 81 wt %, before sulphatisation mixture of brazilite concentrate and sulpuric acid is pressed into briquettes or subjected to extrusion with further division of extrusion product into briquettes, pressing or extrusion of mixture is carried out at pressure 49·105÷7843·104 N/m2, and sulphatisation of briquettes is carried out at temperature 180-200°C. |
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Method of preparing mixed zirconium-cerium-based oxides Invention provides mixed zirconium-cerium-based oxides characterized by thermal resistance and are suitable as promoters or catalyst supports in exhausted gas treatment system of automobiles. Preparation protein comprises reacting alkali with aqueous solution of soluble zirconium salt containing 0.42-07 mole sulfate anions per one mole zirconium cations. Reaction is conducted at temperature not higher than 50°C in presence of soluble cerium salt to form mixed cerium/zirconium hydroxide, which is then calcined to produce mixed oxide. |
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The invention is pertaining to the new mixed oxides produced from ceric oxide and zirconium oxide, which can used as the catalyzers or the catalyzers carriers for purification of the combustion engine exhaust gases. The mixed oxide possesses the polyphase cubical form of the crystallization and oxygenous capacity of at least 260/ micromoles of O2 /g of the sample and the speed of the oxygen extraction of more than 1.0 mg-O2/m2-minute, which are measured after combustion within 4 hours at the temperature of 1000°C. The invention also presents the substrate with the cover containing the indicated mixed oxide. The method of production of the polycrystallic particles of the indicated mixed ceric-zirconium oxide includes the following stages: i) production of the solution of the mixed salt which are containing, at least, one salt of cerium and, at least, one salt of zirconium in the concentration, sufficient for formation of the polycrystallic particles of the corresponding dry product on the basis of the mixed oxide. At that the indicated particles have the cerium-oxide component and zirconium-oxide component, in which these components are distributed inside the subcrystalline structure of the particles in such a manner, that each crystallite in the particle consists of a set of the adjacent one to another domains, in which the atomic ratios of Ce:Zr which are inherited by the adjacent to each other domains, are characterized by the degree of the non-uniformity with respect to each other and determined by means of the method of the X-ray dissipation the small angles and expressed by the normalized intensity of the dissipation I(Q) within the limits from approximately 47 up to approximately 119 at vector of dissipation Q, equal to 0.10 A-1; ii) treatment of the solution of the mixed salt produced in compliance with the stage (i),with the help of the base with formation of sediment; iii) treatment of the sediment produced in compliance with the stage (ii),using the oxidative agent in amount, sufficient for oxidizing Ce+3 up to Ce+4; iv) washing and drying of the residue produced in compliance with the stage (iii); and v) calcination of the dry sediment produced in compliance with the stage (iv),as the result there are produced polycrystallic particles of the oxide of ceric and zirconium in the form of the mixed oxide with the above indicated characteristics. The technical result is the produced mixed oxide possesses both the high oxygenous capacitance, and the heightened speed of the oxygen return in the conditions of the high temperatures. |
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Zirconium oxide-based mesoporous material and a method for preparation thereof Invention provides zirconium oxide-based mesoporous material with following composition: SO42-/ZrO2-EOx, where E represents group III or IV element, x = 1.5 or 2, content of sulfate ions 0.1-10 wt %, and molar ratio ZrO2/EOx = 1:(0.4-1.0), said material having specific surface 300-800 m2/g with total pore volume 0.3 to 0.8 cm3/g. Method involves preparation of composition consisted of hydrated zirconium sulfate, sulfate ions, and water via precipitation of hydrated oxide phase from soluble zirconium or zirconyl salts followed by hydrothermal reprecipitation in presence of cationic surfactants to form mesoporous structure, which is then stabilized by treatment with group III or IV element compounds taken is additive proportions to mesoporous crystalline structure. |
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Heat-resistant coating (options) and article containing it Invention relates to heat-resistant coatings made of ceramic materials and to metallic articles having such type coatings, said articles being effectively applicable in gas-turbine engines. Coatings contain at least one oxide and another oxide selected from zirconium dioxide, cerium oxide, and hafnium oxide, said at least one oxide having general formula A2O3 wherein A is selected from group consisting of La, Pr, Nd, Sm, Eu, Tb, In, Sc, Y, Dy. Ho, Er, Tm, Yb, Lu, and mixtures thereof. Metallic articles are therefore constituted by metal substrate and above defined coating. |
Another patent 2513602.