36results about "Rare earth metal nitrates" patented technology

The invention provides a method for recovering rare earth, aluminum and silicon from rare earth-containing aluminum and silicon wastes. The method comprises the following steps: 1, carrying out acid dipping on the rare earth-containing aluminum and silicon wastes by using an aqueous inorganic acid solution to obtain silicon-rich residues and an acid dipping solution containing rare earth ions and aluminum ions; 2, adding an alkaline substance to the acid dipping solution containing rare earth ions and aluminum ions to control the pH value of the acid dipping solution to be 3.5-5.2, and carrying out solid-liquid separation to obtain an aluminum hydroxide-containing precipitate and a rare earth-containing filtrate; and 3, reacting the aluminum hydroxide-containing precipitate with sodium hydroxide to obtain a sodium metaaluminate solution and aluminum and silicon residues, and using the rare earth-containing filtrate to prepare a rare earth compound product. Aluminum and rare earth are dissolved in the acid, segmented alkaline transfer is carried out, the aluminum ions are precipitated to obtain aluminum hydroxide and the rare earth ions which are separated from the aluminum hydroxide, and excess sodium hydroxide is added to convert aluminum hydroxide into the sodium metaaluminate solution, so simultaneous and high-efficiency recycling of the rare earth and aluminum is realized, the use amount of sodium hydroxide is greatly reduced, and the recovery cost is reduced.

The present invention relates to methods for the separation of rare earth elements from aqueous solutions and, more particularly, to the separation of lanthanides (e.g., neodymium(III)) from aqueous solutions using an organo phosphorus functionalized adsorbent.

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.

Shaded, zirconia ceramic materials are disclosed that are suitable for use in dental applications. Ceramic bodies are made from a zirconia-containing ceramic material and a coloring composition comprising a terbium (Tb)-containing component and a chromium (Cr)-containing component as a coloring agent. The pre-shaded ceramic body is machinable into a dental restoration either as a bisque body or sintered body. A pre-shaded machinable sintered ceramic body may obviate the need for further processing steps, such as shading or sintering, and may be suitable for use in chair-side machining applications, such as in a dentist's office, significantly reducing the time to create a custom finished product.

The invention provides an organic-inorganic hybrid nanoflower and a preparation method thereof, which relate to the technical field of enzyme immobilization. The organic-inorganic hybrid nanoflower provided by the invention is a flower-like immobilized enzyme formed by self-assembly compounding by taking a rare earth layered compound as an inorganic carrier and taking a biological enzyme as an organic component; wherein the rare earth layered compound is Ln2 (OH) 5NO3.nH2O, Ln is one or more of La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb and Y, and n is 1.1-2.5; wherein the biological enzyme is one or more of alpha-amylase, horse radish peroxidase and laccase. According to the invention, the rare earth layered compound is used as an inorganic carrier to load the biological enzyme and form the flower-like immobilized enzyme for the first time, and compared with free enzyme, the obtained immobilized enzyme has better stability and catalytic performance; the preparation method is mild in condition, simple in process and short in consumed time.

A method of extracting metalloid and metal species from a solid or liquid material by exposing the material to a supercritical fluid solvent containing a chelating agent is described. The chelating agent forms chelates that are soluble in the supercritical fluid to allow removal of the species from the material. In preferred embodiments, the extraction solvent is supercritical carbon dioxide and the chelating agent is a fluorinated beta -diketone. In especially preferred embodiments the extraction solvent is supercritical carbon dioxide, and the chelating agent comprises a fluorinated beta -diketone and a trialkyl phosphate, or a fluorinated beta -diketone and a trialkylphosphine oxide. Although a trialkyl phosphate can extract lanthanides and actinides from acidic solutions, a binary mixture comprising a fluorinated beta -diketone and a trialkyl phosphate or a trialkylphosphine oxide tends to enhance the extraction efficiencies for actinides and lanthanides. The method provides an environmentally benign process for removing contaminants from industrial waste without using acids or biologically harmful solvents. The method is particularly useful for extracting actinides and lanthanides from acidic solutions. The chelate and supercritical fluid can be regenerated, and the contaminant species recovered, to provide an economic, efficient process.

According to this method for recovering scandium, an acidic solution containing scandium is used and a scandium dissolution liquid after purification is obtained by a double sulfate precipitation step, and scandium is recovered from the obtained scandium dissolution liquid, as follows: [A] A precipitation step wherein sodium sulfate is added into the acidic solution containing scandium, so that a precipitate of a scandium double sulfate is obtained; [B] A neutralization step wherein pure water is added to the precipitate of a scandium double sulfate obtained in the precipitation step to dissolve the precipitate of a scandium double sulfate therein, and scandium hydroxide is obtained by adding a neutralizing agent into the obtained dissolution liquid; and [C] A re-dissolution step wherein an acid is added to the scandium hydroxide obtained in the neutralization step, so that a scandium dissolution after purification, in which the scandium hydroxide is dissolved, is obtained.

A method for supercritical fluid extraction of metal from a source, the method comprising: providing a reactor chamber; providing a source comprising a target metal; optionally, providing a chelating agent; providing a solvent; adding the source comprising the target metal, the chelating agent and the solvent into the reactor chamber; adjusting the temperature and pressure in the reactor chamber so that the solvent is heated and compressed above its critical temperature and pressure; optionally, providing mechanical agitation to the reactor chamber; recovering a chelate comprising the target metal.

The invention discloses a rare earth solution preparation process capable of quickly and efficiently removing acid. The preparation process comprises the following steps: drying and crushing, grinding, dissolving and stirring, stabilizing the solution, carrying out microwave digestion and carrying out double-layer acid removal. According to the rare earth solution preparation process capable of rapidly and efficiently removing acid, rare earth mineral powder is prepared through the processes of drying, crushing and grinding, after the rare earth mineral powder is dissolved through strong acidand stabilized through a metallic soap stabilizer, part of dissolved sample acid is removed through sulfuric acid or perchloric acid by heating, and then residual acid removing is conducted through atemperature-controlled acid removing instrument; with application of the process, the sample dissolving acid in the rare earth solution can be quickly removed, the residue of the sample dissolving acid is effectively reduced, the time of the preparation process flow is shortened, the acid driving efficiency and the preparation efficiency of the rare earth solution are improved and the process is worthy of popularization.

A process of isolating samarium from a hydrophilic composition comprises nitrate ions, europium and samarium, by reducing europium(III) to europium(II) in this hydrophilic composition, and by extracting the samarium with a water-immiscible organic phase comprising an ionic liquid comprising nitrate anions.

The invention relates to a method for recovering rare earth elements from a solid mixture containing a halophosphate and at least one compound of one or more rare earth elements, including: (a) acid etching the mixture; (b) adding a base to bring the pH back up to a value of at least 1,5; (c) etching the solid from step (b) with a solution of soda or potash; (d) acid etching the solid from step (c) until a pH of less than 7 is obtained, resulting in a solid phase and a liquid phase including at least one rare earth salt, and separating the solid phase from the liquid phase.

The present invention provides a novel anion conductor which comprises a layered metal hydroxide and can be used as an alkaline electrolyte film for use in a fuel cell or the like. An anion conductor characterized by comprising a molded product of a layered metal hydroxide represented by formula (1): [Mx(OH)y(A)([alpha]x-y)/z-nH2O] (wherein M represents a metal that can serve as a bivalent or trivalent cation; [alpha] represents the number of valency of the metal M, A represents an atom or an atomic group that can serve as an anion, and z represents the number of valency of the anion A, wherein, when ([alpha]x-y)/z is 2 or greater, A's may be different types of anions which can serve as anions having the same valencies as each other, or may be anions having different valencies from each other; and n represents the average number of molecules of interlayer water contained per one repeating unit). The anion conductor according to the present invention is composed of an inorganic material, and therefore has excellent heat resistance and physical strength and can be operated for a longer period at a higher temperature compared with the conventional ones when used as an anion conductor for a fuel cell, an air cell or the like.