125results about "Lanthanum oxide/hydroxides" patented technology

Nanowires useful as heterogeneous catalysts are provided. The nanowire catalysts are prepared by polymer templated methods and are useful in a variety of catalytic reactions, for example, the oxidative coupling of methane to ethane and/or ethylene. Related methods for use and manufacture of the same are also disclosed.

Provided is a method of manufacturing a metal oxide film to be formed through the following processes: a coating process of forming a coating film on a substrate by using a coating liquid for forming metal oxide film containing any of various organometallic compounds; a drying process of making the coating film into a dried coating film; and a heating process of forming an inorganic film from the dried coating film under an oxygen-containing atmosphere having a dew-point temperature equal to or lower than −10° C.

A method for recovering rare earth metals from zeolite-containing waste FCC catalysts comprises an acid leaching step to remove the rare earth metals from the catalyst to form a leachate containing dissolved rare earth metals and separating the rare earth metals from the leachate such as by precipitation.

Rare earth compositions comprising nanoparticles, methods of making nanoparticles, and methods of using nanoparticles are described. The compositions of the nanomaterials discussed may include scandium (Sc), yttrium (Y), lanthanum(La), cerium (Ce), praseodymium (Pr), neodymium (Nd), promethium (Pm), samarium (Sm), europium (Eu), gadolinium(Gd), terbium (Tb), dysprosium (Dy), holmium (Ho), erbium (Er), thulium (Tm), ytterbium (Yb), and lutetium (Lu). The nanoparticles can be used to make organometallics, nitrates, and hydroxides. The nanoparticles can be used in a variety of applications, such as pigments, catalysts, polishing agents, coatings, electroceramics, catalysts, optics, phosphors, and detectors.

This invention is a method for producing a cerium-based abrasive which includes: a step of grinding raw material for the cerium-based abrasive; a step of roasting the ground raw material; and a step of subjecting the roasted raw material to wet processing, the method being characterized in that it further includes a lower-temperature re-roasting step of heating the wet-processed raw material at 200 to 700° C. In the invention disclosed in this application, an abrasive with particularly preferable properties can be produced by fully drying the wet-processed raw material in a drying step, and subsequently subjecting the dried raw material to the lower-temperature re-roasting step.

A process for the production of nanorods containing a rare earth metal is disclosed. The process comprises the steps of: (a) increasing the pH of an aqueous solution of the formula MX₃, where M is a trivalent rare earth metal cation and X is a monovalent anion so as to produce a reaction product containing X anions in solution and a precipitate in the form of trivalent rare earth hydroxide nanoparticles of the formula M(OH)₃, the nanoparticles having a hexagonal crystal structure; and, (b) ageing the nanoparticles of step (a) in the presence of the reaction product containing X anions in solution so as to cause rod-like anisotropic growth of the nanoparticles and form rare earth hydroxide nanorods.

The present invention is directed to a process for the preparation of a doped anionic clay. In said process a trivalent metal source is reacted with a divalent metal source, at least one of the metal sources being either doped boehmite, doped MgO or doped brucite, to obtain a doped anionic clay. Suitable dopants are compounds containing elements selected from the group of alkaline earth metals (for instance Ca and Ba), alkaline metals, transition metals (for example Co, Mn, Fe, Ti, Zr, Cu, Ni, Zn, Mo, W, V, Sn), actinides, rare earth metals such as La, Ce, and Nd, noble metals such as Pt and Pd, silicon, gallium, boron, titanium, and phosphorus.

There are provided processes for preparing alumina. These processes can comprise leaching an aluminum-containing material with HCl so as to obtain a leachate comprising aluminum ions and a solid, and separating said solid from said leachate; reacting said leachate with HCl so as to obtain a liquid and a precipitate comprising said aluminum ions in the form of AlCl₃, and separating said precipitate from said liquid; and heating said precipitate under conditions effective for converting AlCl₃ into Al₂O₃ and optionally recovering gaseous HCl so-produced. These processes can also be used for preparing various other products such as hematite, MgO, silica and oxides of various metals, sulphates and chlorides of various metals, as well as rare earth elements, rare metals and aluminum.

Various embodiments relate to separation of terbium(III,IV) oxide. In various embodiments, present invention provides a method of separating terbium(III,IV) oxide from a composition. The method can include contacting a composition including terbium(III,IV) oxide and one or more other trivalent rare earth oxides with a liquid including acetic acid to form a mixture. The contacting can be effective to dissolve at least some of the one or more other trivalent rare earth oxides into the liquid. The method can include separating undissolved terbium(III,IV) oxide from the mixture, to provide separated terbium(III,IV) oxide.

An object of the present invention is to provide a cerium oxide abrasive material containing cerium oxide abrasive particles prepared by a synthetic method using an aqueous solution of a salt of a rare earth element and a precipitant, the cerium oxide abrasive particles having a spherical shape and high polishing performance (polishing rate and polishing precision of the polished surface), a method for producing the cerium oxide abrasive material, and a polishing method. The cerium oxide abrasive material according to the present invention comprises spherical cerium oxide abrasive particles prepared by a synthetic method using an aqueous solution of a salt of a rare earth element and a precipitant, wherein the cerium oxide abrasive particles have a spherical shape having an average aspect ratio within the range of 1.00 to 1.15.

The invention relates to a composition containing oxides of zirconium, cerium and another rare earth different from cerium, having a cerium oxide content not exceeding 50 wt% and, after calcination at 1000 DEG C for 6 hours, a maximal reducibility temperature not exceeding 500 DEG C and a specific surface of at least 45 m2/g. The composition is prepared according to a method that comprises continuously reacting a mixture containing compounds of zirconium, cerium and another rare earth having a basic compound for a residence time not exceeding 100 milliseconds, wherein the precipitate is heated and contacted with a surfactant before calcination.

A method is described to produce high purity rare earth oxides of the elements La, Ce, Tb, Eu and Y from phosphor, such as waste phosphor powders originating in various consumer products. One approach involves leaching the powder in two stages and converting to two groups of relatively high purity mixed rare earth oxides. The first group containing Eu and Y is initially separated by solvent extraction. Once separated, Eu is purified using Zn reduction with custom apparatus. Y is purified by running another solvent extraction process using tricaprylmethylammonium chloride. Ce is separated from the second group of oxides, containing La, Ce and Tb by using solvent extraction. Subsequently, La and Tb are separated from each other and converted to pure oxides by using solvent extraction processes. A one-stage leaching process, wherein all rare earths get leached into the solution and subsequently processed, is also described.

An object of the present invention is to provide a method for producing a metal hydroxide fine particle, which can produce metal hydroxide fine particles with favorable crystallinity and small particle sizes. The present invention provides a method for producing a metal hydroxide fine particle by reacting a metal ion with a hydroxide ion in a solvent, which includes a mixing and reacting step of supplying the metal ion, the hydroxide ion, and a silane coupling agent to a reaction field to mix and react the ions.

The invention discloses a preparation method of a high-performance ultra-fine grain molybdenum and lanthanum alloy. The preparation method comprises the following steps that 1) spherical nano La2O3 isprepared; 2) molybdenum powder is prepared; 3) mixed powder is prepared; and 4) a molybdenum alloy is prepared, and namely, after the mixed powder is subjected to weight balancing, SPS rapid sintering is performed to obtain the La2O3-Mo molybdenum alloy. According to the preparation method, a La2O3 second phase is prepared by using a water bath method, the purpose of controlling the size and theappearance of the second phase can be achieved by controlling the time length of the water bath and the size of the cooling speed, so that the very fine spherical La2O3 is obtained, particles of the second phase are smaller, so that the distribution is more uniform, and the particles are easier to enter the interiors of the Mo alloy grains, and more obvious strengthening effect is achieved. The strengthening effect of the spherical La2O3 is best, the possibility of micro-cracks is small due to the fact that the tendency of the stress concentration is small, the breaking strength can be furtherimproved, the cracks will deviate from the original main expansion direction, dislocation loops are formed, and therefore, the yield strength and tensile strength are improved.

The invention belongs to the technical field of composite materials, and particularly relates to a preparation method of a carbon fiber/rare earth oxide nanowire mixed reinforcement, as well as an obtained material and application of the carbon fiber/rare earth oxide nanowire mixed reinforcement. The preparation method comprises the following steps of placing a carbon fiber preform in a rare earth salt reaction solution, magnetically stirring, performing high-temperature and high-pressure in-situ synthesis reaction, cleaning, drying and calcining to obtain the carbon fiber/rare earth oxide nanowire mixed reinforcement. According to the preparation method provided by the invention, reagents which are high in cost and pollute the environment are not used, the preparation process is simple and controllable, the reaction temperature is low, and the composition, the content and the like of rare earth oxide nanowires can be controlled through design of the reaction solution proportion and reaction conditions; and the mixed reinforcement prepared by the preparation method disclosed by the invention can give consideration to the cross-scale synergistic reinforcement advantage of carbon fibers and nanowires on an interface and a matrix and the modification effect of rare earth on the surface of the carbon fibers, and can be used for reinforcing polymers, carbon and ceramic-based composite materials.

Disclosed are a composite oxide which is capable of maintaining a large volume of pores even used in a high temperature environment, and which has excellent heat resistance and catalytic activity, as well as a method for producing the composite oxide and a catalyst for exhaust gas purification employing the composite oxide. The composite oxide contains cerium and at least one element selected from aluminum, silicon, or rare earth metals other than cerium and including yttrium, at a mass ratio of 85:15 to 99:1 in terms oxides, and has a property of exhibiting a not less than 0.30 cm³/g, preferably not less than 0.40 cm³/g volume of pores with a diameter of not larger than 200 nm, after calcination at 900° C. for 5 hours, and is suitable for a co-catalyst in a catalyst for vehicle exhaust gas purification.

Processes and systems for carbon ion implantation include utilizing phosphorous trifluoride (PF₃) as a co-gas with carbon oxide gas, and in some embodiments, in combination with the lanthanated tungsten alloy ion source components advantageously results in minimal oxidation of the cathode and cathode shield. Moreover, acceptable levels of carbon deposits on the arc chamber internal components have been observed as well as marked reductions in the halogen cycle, i.e., WF_x formation.