703results about "Rare earth metal compounds preparation/treatment" patented technology

The production method for cerium oxide particles of the present invention is a method of producing a cerium oxide particle by heating a cerium compound from a normal temperature to a temperature range of 400° C. to 1200° C., and comprises at least a temperature raising stage of a temperature rise speed of 2° C. / hour to 60° C. / hour, or proceeds via a stage of heating while supplying a humidified gas in a temperature raising process. By the method of the present invention, a cerium oxide powder whose particle diameter distribution of primary particles is narrow can be obtained. An aqueous cerium oxide slurry produced from the powder enables an improvement in the productivity and a reduction in the cost of a polishing step, because if it is used as an abrasive a high-quality polished face is obtained without deteriorating the polishing speed. The aqueous cerium oxide slurry of the present invention is particularly useful as an abrasive for final finish of a substrate whose main component is silica.

The production method for cerium oxide particles of the present invention is a method of producing a cerium oxide particle by heating a cerium compound from a normal temperature to a temperature range of 400° C. to 1200° C., and comprises at least a temperature raising stage of a temperature rise speed of 2° C. / hour to 60° C. / hour, or proceeds via a stage of heating while supplying a humidified gas in a temperature raising process. By the method of the present invention, a cerium oxide powder whose particle diameter distribution of primary particles is narrow can be obtained. An aqueous cerium oxide slurry produced from the powder enables an improvement in the productivity and a reduction in the cost of a polishing step, because if it is used as an abrasive a high-quality polished face is obtained without deteriorating the polishing speed. The aqueous cerium oxide slurry of the present invention is particularly useful as an abrasive for final finish of a substrate whose main component is silica.

Processes described include reacting a fresh or spent catalyst, or sorbent, with a solution containing an extracting agent (such as an acid or a base). Preferably, the catalyst contains both alumina and a molecular sieve (or a sorbent), and the reaction is performed under relatively mild conditions such that the majority of the base material does not dissolve into the solution. Thus, the catalyst can be re-used, and in certain instances the performance of the catalyst even improves, with or without re-incorporating certain of the metals back into the catalyst. Additionally, metals contained in the catalyst, such as Na, Mg, Al, P, S, Cl, K, Ca, V, Fe, Ni, Cu, Zn, Sr, Zn Sb, Ba, La, Ce, Pr, Nd, Pb, or their equivalent oxides, can be removed from the catalyst. Some of the metals that are removed are relatively valuable (such as the rare earth elements of La, Ce, Pr and Nd).

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 invention concerns a cyclic method for separating at least one chemical element E1 from at least one chemical element E2 from an aqueous solution containing said elements, which employs a mixture of two extractants operating in non-overlapping chemical fields. Each cycle of said method comprises: a) co-extracting elements E1 and E2 by means of an organic phase containing a first extractant suited to causing the migration of said elements into said organic phase; b) adding to the organic phase a second extractant suited to selectively retaining the element(s) E2 in said organic phase during step c): c) selectively stripping the element(s) E1 from the organic phase; d) selectively stripping the element(s) E2 from the organic phase; e) separating the first and second extractants present in said organic phase at the end of step d).

The invention concerns a cyclic method for separating at least one chemical element E1 from at least one chemical element E2 from an aqueous solution containing said elements, which employs a mixture of two extractants operating in non-overlapping chemical fields.Each cycle of said method comprises: a) co-extracting elements E1 and E2 by means of an organic phase containing a first extractant suited to causing the migration of said elements into said organic phase; b) adding to the organic phase a second extractant suited to selectively retaining the element(s) E2 in said organic phase during step c): c) selectively stripping the element(s) E1 from the organic phase; d) selectively stripping the element(s) E2 from the organic phase; e) separating the first and second extractants present in said organic phase at the end of step d).

A cerium salt wherein, when 20 g of the cerium salt is dissolved in a mixed liquid of 12.5 g of 6N nitric acid and 12.5 g of a 30% hydrogen peroxide aqueous solution, a concentration of an insoluble component present in the solution is 5 ppm or less by mass ratio to the cerium salt before dissolution and cerium oxide produced by processing the cerium salt at high temperatures. Scratch on a surface to be polished can be reduced when a cerium based polishing slurry containing the cerium oxide particles is used, since an amount of impurities in cerium oxide particles and cerium salt particles, raw material thereof, is reduced for high purification.

Provided is a method of recovering rare-earth elements by which rare-earth elements can be recovered efficiently from a bauxite residue serving as a raw material and containing the rare-earth elements. Specifically provided is a method of recovering rare-earth elements from a raw material, the raw material being a bauxite residue produced as a by-product in a Bayer process, the method including: using a bauxite residue having a specific surface area of 35 m2 / g or more; adding, to the raw material bauxite residue, a liquid leaching agent formed of an aqueous solution of at least one kind of mineral acid selected from sulfuric acid, hydrochloric acid, nitric acid, and sulfurous acid, thereby preparing a slurry having a liquid-solid ratio of 2 to 30 and a pH of 0.5 to 2.2; subjecting the slurry to leaching treatment of the rare-earth elements under a temperature condition of room temperature to 160° C.; subjecting the slurry after the leaching treatment to solid-liquid separation, yielding a leachate; and separating and recovering the rare-earth elements from the leachate.

A cerium salt wherein, when 20 g of the cerium salt is dissolved in a mixed liquid of 12.5 g of 6N nitric acid and 12.5 g of a 30% hydrogen peroxide aqueous solution, a concentration of an insoluble component present in the solution is 5 ppm or less by mass ratio to the cerium salt before dissolution and cerium oxide produced by processing the cerium salt at high temperatures. Scratch on a surface to be polished can be reduced when a cerium based polishing slurry containing the cerium oxide particles is used, since an amount of impurities in cerium oxide particles and cerium salt particles, raw material thereof, is reduced for high purification.

A new inorganic scintillating material is provided represented by the formula Ln(1-m-n)HfnCemA(3+n), where A is Br or Cl, or I, or a mixture of at least two halogens of the group, Ln is an element from the group: La, Nd, Pm, Sm, Eu, Gd, Tb, Lu, Y. A new crystal scintillator is also provided represented by the formula Ln(1-m)CemA3:n.Hf4+, where Ln(1-m)CemA3 represents the chemical composition of the matrix material, A is Br, or Cl, or I, or a mixture of at least two halogens from the group, Ln is an element from the group: La, Nd, Pm, Sm, Eu, Gd, Tb, Lu, Y; Hf4+ is a dopant. A radiation detector comprising a scintillating element based on the novel inorganic scintillating material is also provided.

A target light rare earth element is separated from an aqueous solution containing two or more of La, Ce, Pr and Nd by contacting an organic phase containing an extractant with the aqueous solution in a counter-current flow multistage mixer-settler while adding an alkaline solution thereto, and contacting the organic phase with an acid aqueous solution for back-extracting the target element. The extractant is a dialkyl diglycol amic acid having formula: R1R2NCOCH2OCH2COOH, wherein R1 and R2 are alkyl, at least one having at least 6 carbon atoms.

The invention discloses a preparation method of lanthanum zirconate spherical powder for thermal spraying, wherein the method comprises the following steps: carrying out wet ball milling on La2O3 andZrO2 in a molar ratio of 1:2 and a molten salt medium, uniformly mixing, drying the mixture, heating to 900-1200 DEG C, keeping the temperature for 4-10 h, and cooling to room temperature; washing thereaction product with water to remove the residual molten salt medium, adding a binder and deionized water to obtain slurry, and granulating the slurry by using spray drying equipment to obtain spherical powder; and calcining the prepared spherical powder at high temperature to remove the binder and densify the spherical powder to obtain the lanthanum zirconate spherical powder for thermal spraying. Molten salt is used as a reaction medium to provide a liquid-phase environment, so that the reaction temperature is reduced, and the growth of particles is avoided; oxides are adopted as raw materials, the conversion efficiency and the production efficiency are high, molten salt can be recycled, the synthesis cost is low, time is short, operation is easy, and the method is suitable for mass production.

Disclosed is a method for preparing cerium carbonate powder by mixing a cerium precursor solution with a carbonate precursor solution to cause precipitation, wherein at least one solvent used in the cerium precursor solution and the carbonate precursor solution is an organic solvent. Cerium carbonate powder obtained from the method, cerium oxide powder obtained from the cerium carbonate powder, a method for preparing the cerium oxide powder, and CMP slurry comprising the cerium oxide powder are also disclosed. The method for preparing cerium carbonate using an organic solvent, allows the resultant cerium carbonate powder to have a size and shape controllable from the initial nucleation step. Additionally, it is possible to easily control the size and shape of cerium oxide powder obtained from the cerium carbonate powder.

Disclosed is a method for directly preparing cerium oxide powder in a solution phase by a) mixing a cerium precursor solution with a precipitant solution to cause a reaction; and b) performing oxidation treatment of the reacted solution, wherein at least one kind of pure organic solvent containing no water is used as a solvent for the cerium precursor solution as well as the precipitant solution to thereby prepare the cerium oxide powder, the particle size of which is adjusted to 50nm to 3 mum. Cerium oxide powder obtained from the method and CMP slurry comprising the cerium oxide powder as apolishing agent are also disclosed. The method makes it possible to prepare cerium oxide powder with an average particle size of 50nm or greater and high crystallinity, which is difficult to prepare by the conventional wet precipitation process, by using an organic solvent as a solvent in a wet precipitation process, and the so-prepared cerium oxide powder can be used as a polishing agent for CMPslurry even without being subjected to separate heat treatment.

The objective of the present invention is to selectively extract light rare earth metals, and by extension, europium, from an acidic solution containing a plurality of types of rare earth metal. This valuable metal extraction agent is represented by the general formula. In the formula: R1 and R2 each indicate the same or different alkyl group; R3 indicates a hydrogen atom or an alkyl group; and R4 indicates a hydrogen atom or any given group other than an amino group bonded to the α carbon as an amino acid. Preferably, the general formula has a glycine unit, a histidine unit, a lysine unit, an aspartic acid unit, or an N-methylglycine unit. Preferably, when extracting europium using the extraction agent, the pH is adjusted into the range of 2.0-3.0 inclusive, and when selectively extracting light rare earth metals, the pH is adjusted to 1.7-2.7 inclusive.

Provided are a method of preparing solid electrolyte particles of Chemical Formula 1 including preparing a precursor solution by mixing a titanium precursor, a lanthanum precursor, and a lithium precursor in an aqueous or organic solvent, and heat treating the precursor solution, solid electrolyte particles prepared thereby, and a lithium secondary battery including the solid electrolyte particles:Li3xLa(2 / 3-x)TiO3 (0<x<0.16).   <Chemical Formula 1>According to a method of preparing solid electrolyte particles according to an embodiment of the present invention, solid electrolyte particles may be easily prepared by heat treating at low temperature for a short period of time.

The invention discloses a preparation method of anhydrous lanthanum bromide, which comprises the following steps: (1) well mixing ammonium bromide with lanthana; (2) heating the mixture obtained in step (1) in closed environment with a certain leakproofness to obtain anhydrous lanthanum bromide. The method of the invention is easily available in raw materials, and low in cost; the preparation process is simple, short in flow, easy to control, high in product yield, and low in production cost; the prepared anhydrous lanthanum bromide is high in purity, and has a purity of up to 99.5%; and the preparation method can be used for preparation of lanthanum bromide scintillation crystals, and has very good industrial and commercial prospects.

Disclosed is a method for directly preparing cerium oxide powder in a solution phase by a) mixing a cerium precursor solution with a precipitant solution to cause a reaction; and b) performing oxidation treatment of the reacted solution, wherein at least one kind of pure organic solvent containing no water is used as a solvent for the cerium precursor solution as well as the precipitant solution to thereby prepare the cerium oxide powder, the particle size of which is adjusted to 50 nm to 3 μm. Cerium oxide powder obtained from the method and CMP slurry comprising the cerium oxide powder as a polishing agent are also disclosed. The method makes it possible to prepare cerium oxide powder with an average particle size of 50 nm or greater and high crystallinity, which is difficult to prepare by the conventional wet precipitation process, by using an organic solvent as a solvent in a wet precipitation process, and the so-prepared cerium oxide powder can be used as a polishing agent for CMP slurry even without being subjected to separate heat treatment.

A method for recycling rare earth from a wastewater from rare earth mining or from rare earth smelting, includes the steps of: removing oil from the wastewater to obtain a degreased wastewater; purifying the degreased wastewater to obtain a purified wastewater using a pretreatment system; recycling rare earth from the purified wastewater to obtain a rare earth slurry and a low rare earth wastewater using a rare earth recycling tank; treating the low rare earth wastewater to obtain ammonia gas using an ammonium degassing device; and converting the ammonia gas to obtain aqueous ammonia using an aqueous ammonium preparing system.

The present invention relates to a method for preparing cerium carbonate-based compound, which is capable of easily controlling the crystalline structure, size, shape, or etc. of the cerium carbonate-based compound, and of preparing the cerium carbonate-based compound efficiently at low cost.The method for preparing cerium carbonate-based compound includes comprising the steps of reacting Lanthanite-(Ce) at an elevated temperature to form cerium oxycabonate hydrate (Ce2O(CO3)2.H2O) with orthorhombic crystal structure, or cerium hydroxycarbonate (Ce(OH).(CO3)) with hexagonal crystal structure.

The invention discloses a method of separating thulium, ytterbium and lutetium through extraction, and belongs to the technical field of rare earth metal extraction. The method includes the steps of: (1) separating a TmYbLu chloride solution with an organic phase, which supports a TmYb water phase, and a (YbLu)Cl3 solution; (2) separating the TmYb water phase with the organic phase and a YbCl3 solution to obtain a pure Tm water phase and a Yb organic phase, and dividing the supported organic phase and feeding the supported organic phase into the step (1) to separate the TmYbLu chloride solution; (3) separating a YbLu organic phase with a LuCl3 solution and the Yb organic phase, and feeding a part of a pure Yb water phase to the step (2); (4) in a Yb / Lu separation trough, dividing a part of a YbLu water phase and feeding the YbLu water phase into the step (1). The method is used for extraction separation of high-purity thulium, ytterbium and lutetium, is low in separation cost and generates less separation wastewater, has high product recovery rate and is short in separation time.

The invention relates to a method for separating and extracting rare earth and regenerated rare earth polishing powder from waste rare earth polishing powder. The method is characterized by comprising the following steps that a primary acid leaching, alkali fusion and secondary acid leaching combined treatment process is firstly used for separating and extracting the rare earth in the waste rare earth polishing powder to obtain rare earth chloride leachate; then ammonia water is used for precipitation and impurity removing, and hydrochloric acid is used for acidolysis to obtain a purified rare earth chloride solution; then, hydrofluoric acid, an ammonium bicarbonate solution and a dispersing agent are used for coprecipitation to obtain a rare earth chloride solution so as to obtain cerium lanthanum fluorocarbonate powder; and finally, the regenerated rare earth polishing powder with good polishing performance is obtained through drying, two-stage high-temperature calcination and ball milling. According to the method, the total leaching rate of the rare earth in the waste rare earth polishing powder reaches 95% or above, the total recycle rate of the rare earth reaches 93% or above, and efficient separation, extraction and recycling of the rare earth in the waste rare earth polishing powder are achieved.

The present invention relates to cerium oxide powder and a process for producing the same. The cerium oxide powder of the invention, which is produced by mixing a cerium source such as cerium oxide, cerium hydroxide and cerium carbonate with an alkali metal compound, as flux, and performing high temperature treatment, may have a variety particle size while having spherical shape.

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.

The objective of the present invention is to selectively extract cobalt from an acidic solution containing a high concentration of manganese. This cobalt extraction method extracts cobalt from an acidic solution containing manganese and cobalt by subjecting the acidic solution to solvent extraction by means of a valuable metal extraction agent comprising an amide derivative represented by general formula (I). The valuable metal extraction agent is represented by the general formula. In the formula: R1 and R2 each represent the same or different alkyl group; R3 represents a hydrogen atom or an alkyl group; and R4 represents a hydrogen atom or any given group aside from an amino group bonded to the α carbon as an amino acid. Preferably, the general formula has a glycine unit, a histidine unit, a lysine unit, an aspartic acid unit, or an N-methylglycine unit. Preferably, the pH of the acidic solution is 3.5-5.5 inclusive.

Processes described include reacting a fresh or spent catalyst, or sorbent, with a solution containing an extracting agent (such as an acid or a base). Preferably, the catalyst contains both alumina and a molecular sieve (or a sorbent), and the reaction is performed under relatively mild conditions such that the majority of the base material does not dissolve into the solution. Thus, the catalyst can be re-used, and in certain instances the catalyst performance even improves, with or without re-incorporating certain of the metals back into the catalyst. Additionally, metals contained in the catalyst, such as Na, Mg, Al, P, S, Cl, K, Ca, V, Fe, Ni, Cu, Zn, Sr, Zn Sb, Ba, La, Ce, Pr, Nd, Pb, or their equivalent oxides, can be removed from the catalyst. Some of the metals that are removed are relatively valuable (such as the rare earth elements of La, Ce, Pr and Nd).

Provided is a method of recovering rare-earth elements by which rare-earth elements can be recovered efficiently from a bauxite residue serving as a raw material and containing the rare-earth elements. Specifically provided is a method of recovering rare-earth elements from a raw material, the raw material being a bauxite residue produced as a by-product in a Bayer process, the method including: using a bauxite residue having a specific surface area of 35 m2 / g or more; adding, to the raw material bauxite residue, a liquid leaching agent formed of an aqueous solution of at least one kind of mineral acid selected from sulfuric acid, hydrochloric acid, nitric acid, and sulfurous acid, thereby preparing a slurry having a liquid-solid ratio of 2 to 30 and a pH of 0.5 to 2.2; subjecting the slurry to leaching treatment of the rare-earth elements under a temperature condition of room temperature to 160° C.; subjecting the slurry after the leaching treatment to solid-liquid separation, yielding a leachate; and separating and recovering the rare-earth elements from the leachate.

The present invention relates to a process, method and plant for recovering scandium and ions containing scandium using an ion exchange resin from a feed stream. The feed stream may be, but is by no means limited to, a leach liquor or leach pulp.

The invention provides a nano-dephosphorizer lanthanum carbonate hydrate, La2(CO3)3.nH2O, 1 <= n <= 8. The invention also provides a preparation method of the nano-dephosphorizer lanthanum carbonate hydrate. The method includes steps of: 1) adding an ionic liquid to a metal lanthanum ion solution with stirring to form a mixed solution; 2) adding a precipitant to the mixed solution to perform a precipitation reaction, and performing after-treatment to a reaction product to obtain the nano-dephosphorizer lanthanum carbonate hydrate, which is more than 100 mg / L in maximum saturation adsorption capacity and has strong removal capability on low-content phosphorus components in ecologic water domains, living or industrial wastewater, etc. After treatment, content of phosphates in the water sample can reach national first-level emission standard of phosphates. The nano-dephosphorizer has important significance for alleviating the gaining pressure of phosphorus environment pollution and a problem of daily production and domestic water.

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.