Grirem Advanced Materials Co., Ltd.

General Research Institute for Nonferrous Metals

Grirem Hi-tech Co., Ltd.

Rare Earth Functional Materials (xiong'an) Innovation Center Co., Ltd.

General Research Institute for Nonferrous Metals, Beijing

Xiaowei Huang

Hongwei Li

Liangshi Wang

Dali Cui

Zhiqi Long

Weidong Zhuang

Yunsheng Hu

Yongke Hou

Yang Xu

Huaqiang He

Ying Yu

Zongyu Feng

Meisheng Cui

Na Zhao

Yuanhong Liu

Ronghui Liu

Xu Guang Sun

Zhen Long

Shusheng Zhang

Xinlin Peng

Guilin Yang

Chunmei Wang

Yongqi Zhang

Qiang Zhong

Lei Wang

Hao Wang

Qi Wang

Meng Wang

Qian Ma

He Fang Zhang

Wei Gao

Tao He

Chunlei Zhao

Ying Fang

Huibing Xu

Shunli Zhang

Huagiang He

Jinyu Wang

Zhizhe Zhai

Chao Xia

Xiangsheng Liu

Longsheng Zhao

Mei Yue

Xiaofang Zhou

Xingliang Feng

The present invention provides a process for metallurgy and separating a rare earth concentrate using a combination method, the process including: treating the rare earth concentrate containing bastnaesite by using a method including roasting under an atmosphere, leaching with hydrochloric acids, and roasting with a sulfuric acid, wherein stepping acid leaching with low-concentration hydrochloric acids is controlled during the leaching with the hydrochloric acids so as to obtain a rare earth solution with a high concentration (150-250 g/L REO), such that a leaching rate of Ce reaches 60% or more, and the content of F in a leaching liquor is reduced by aging; and rare earth is further recovered from a leach residue by roasting with the sulfuric acid and leaching with water, and the total yield of the rare earth reaches 95% or more.

Process for metallurgy and separating rare earth concentrate using combination method

The present invention discloses a rare-earth-manganese/cerium-zirconium-based composite compound, a method for preparing the same, and a use thereof. The composite compound is of a core-shell structure with a general formula expressed as: A REBO-(1-A)CeZrMO, wherein 0.1≤A≤0.3, preferably 0.1≤A≤0.2; a shell layer has a main component of rare-earth manganese oxide with a general formula of REMnO, wherein RE is a rare-earth element or a combination of more than one rare-earth elements, and B is Mn or a combination of Mn and a transition metal element, 1≤a≤8, 2≤b≤18, and 0.25≤c≤4; and a core has a main component of cerium-zirconium composite oxide with a general formula of CeZrMO, wherein M is one or more non-cerium rare-earth elements, 0.1≤x≤0.9, 0≤y≤0.3, and 0.01≤z≤0.3. The composite compound enhances an oxygen storage capacity of a cerium-zirconium material through an interface effect, thereby increasing a conversion rate of a nitrogen oxide.

Rare-earth-manganese/cerium-zirconium-based composite compound, method for preparing same and use thereof

Disclosed is a method of recovering rare earth, aluminum and silicon from rare earth-containing aluminum-silicon scrap. The method comprises: S1, acid-leaching the rare earth-containing aluminum-silicon scrap with an inorganic acid aqueous solution to obtain a silicon-rich slag and acid leached solution containing rare earth and aluminum element; S2, adding an alkaline substance into the acid leached solution containing the rare earth and aluminum element and controlling a PH value of the acid leaching solution between 3.5 to 5.2, performing a solid-liquid separation to obtain a aluminum hydroxide-containing precipitate and a rare earth-containing solution filter; S3, reacting the aluminum hydroxide containing precipitate with sodium hydroxide to obtain sodium metaaluminate solution and aluminum-silicon slag, and preparing a rare earth compound product with the rare earth-containing filtrate. The method dissolves an the aluminum and the rare earth with the acid and then via step wise alkaline conversion, convert aluminum icons to an aluminum hydroxide precipitate separated from rare earth ions, and then adds excessive amounts of sodium hydroxide to convert the aluminum hydroxide to a sodium metaaluminate solution, thereby realizing high-efficiency recovery of both rare earth and aluminum while significantly reducing the consumption of the sodium hydroxide and thus recovery cost.

Method of recovering rare earth aluminum and silicon from rare earth-containing aluminum-silicon scraps

Provided are a cerium-zirconium composite oxide, a preparation method therefor and application of a catalyst. The cerium-zirconium composite oxide has a composite phase structure, and comprises a cerium oxide phase and a cerium-zirconium solid solution phase, or consists of two or more cerium-zirconium solid solution phases with different crystal structures and different chemical compositions, wherein the chemical formula of the cerium-zirconium solid solution phase is CeZrMO, where M is at least one selected from the group consisting of a rare earth element other than cerium, a transition metal element and an alkaline earth metal element, x is 15-85 mol %, and y is 0-20 mol %.

Cerium-zirconium composite oxide, preparation method therefor, and application of catalyst

The present disclosure relates to a fluorescent powder and a light-emitting device including the same. The fluorescent powder includes an inorganic compound. The inorganic compound contains components including an element M, an element A, an element D, an element E, and an element R. The element M is selected from Eu, Ce, Mn, Tb, Dy, and Tm, the element A is selected from Mg, Ca, Sr, and Ba, the element D is selected from B, Al, Ga, In, La, Gd, Sc, Lu, and Y, the element E is selected from Si, Ge, Zr, and Hf, and the element R is at least two elements selected from N, O, F, and Cl. In a powder X-Ray Diffraction (XRD) spectrum with CoK&#x3b1; radiation, the inorganic compound at least has diffraction peaks within ranges of an Bragg angle (2&#x3b8;) from 27.3&#xb0; to 28.3&#xb0;, 29.7&#xb0; to 30.7&#xb0;, 41.9&#xb0; to 42.9&#xb0;, and 43.5&#xb0; to 44.5&#xb0;.

Fluorescent powder and light-emitting device including the same

A method for comprehensively recovering rare earth elements and fluorine element in a bastnaesite treatment process. The method comprises: oxidation roasting a bastnaesite, and leaching a roasted mixture using a hydrochloric acid, adding a roasting promoter to the bastnaesite during the roasting process; and/or during the leaching process using the hydrochloric acid, adding a catalytic leaching promoter into the mixture, obtaining a rare earth chloride solution containing little cerium element and a cerium-rich residue containing the fluorine element; and separating and recovering rare earth fluorides from the cerium-rich residue.

Method for comprehensively recovering rare earth elements and fluorine element in a bastnaesite treatment process

The present invention provides a cerium oxide based composite polishing powder and a preparation method thereof. The polishing powder contains the element magnesium in an amount of 0.005 wt %-5 wt % to magnesium oxide meter. The preparation method includes: (1) uniformly mixing a salt solution containing cerium serving as the main component of the polishing powder; (2) uniformly mixing a precipitating agent of an aqueous magnesium bicarbonate solution with the mixed solution prepared in step (1) to obtain a slurry; (3) aging the slurry prepared in step (2) for 0-48 h while the temperature of the slurry is kept at 30-90 degrees centigrade, and filtering the aged slurry to obtain the precursor powder of the polishing powder; (4) calcinating the precursor powder at 600-1000 degrees centigrade, then dispersing and separating the calcinated precursor powder to obtain the polishing powder. The present invention improves the polishing performance and the suspension performance of polishing powder.

Cerium oxide based composite polishing powder and preparation method thereof

An oxynitride orange-red fluorescent substance and a light-emitting film or sheet and a light-emitting device comprising the same are disclosed. The chemical formula of the oxynitride orange-red fluorescent substance is MASiNO:dR in which the element M is one or more of the elements selected from Ca, Sr and Ba, the element A is Al or a mixture of Al with one or more of the elements selected from Ga, La, Sc and Y, the element R is one or more of the elements selected from Ce, Eu and Mn, 0.8&#x2266;m&#x2266;1.2, 1&#x3c;a&#x3c;1.7, 1&#x3c;x&#x3c;1.7, 3&#x3c;y&#x3c;4.2, 0&#x3c;z&#x3c;0.7, and 0.001&#x2266;d&#x2266;0.2.

Oxynitride orange-red fluorescent substance and light-emitting film or sheet and light-emitting device comprising the same

A silicon-containing phosphor for LED and its preparation method, and the devices incorporating the same. The phosphor in the present invention can be represented as AO.aSiO.bAX:mEu,nR, wherein A is at least one metal element selected from a group consisting of Sr, Ba, Ca, Mg, and Zn; X is at least one halogen element selected from a group consisting of F, Cl, Br, and I; R is at least one element selected from a group consisting of Bi, Y, La, Ce, Pr, Gd, Tb, and Dy; 0.1&#x3c;a&#x3c;2, 0.005&#x3c;b&#x3c;0.08, 0.005&#x3c;m&#x3c;0.5, 0.005&#x3c;n&#x3c;0.5, and m+n&#x3c;1. The phosphor has excellent luminescent performance and good stability, wide excitation band, and adjustable emission wavelength. White or color LED can be obtained by combining the phosphor of the present invention with UV, purple or blue light LED chip.

Silicon-containing phosphor for LED, its preparation and the light emitting devices using the same

The present invention relates to a method of precipitation of metal ions. Mineral(s), oxide(s), hydroxide(s) of magnesium and/or calcium are adopted as raw materials, and the raw material(s) is processed through at least one step of calcination, slaking, or carbonization to produce aqueous solution(s) of magnesium bicarbonate and/or calcium bicarbonate, and then the solution(s) is used as precipitant(s) to deposit rare earth, such as nickel, cobalt, iron, aluminum, gallium, indium, manganese, cadmium, zirconium, hafnium, strontium, barium, copper and zinc ions. And at least one of metal carbonates, hydroxides or basic carbonates is obtained, or furthermore the obtained products are calcined to produce metal oxides. The invention takes the cheap calcium and/or magnesium minerals or their oxides, hydroxides with low purity as raw materials to instead common precipitants such as ammonium bicarbonate and sodium carbonate etc. The calcium, magnesium, carbon dioxide etc are efficiently and circularly used, and the environment pollution by ammonium-nitrogen wastewater, high concentration salts wastewater is avoided, and both of the discharge of greenhouse gas carbon dioxide and the production cost of metal are decreased.

Method of precipitation of metal ions

The application of aqueous solution of magnesium bicarbonate and/or calcium bicarbonate in the process of extraction separation and purification of metals is disclosed, wherein the aqueous solution of magnesium bicarbonate and/or calcium bicarbonate is used as an acidity balancing agent, in order to adjust the balancing pH value of the extraction separation process which uses an acidic organic extractant, improve the extraction capacity of organic phase, and increase the concentration of metal ions in the loaded organic phase.

Use of Mg(HCO3)2 and/or Ca(HCO3)2 aqueous solution in metal extractive separation and purification

A phosphor can be excited by UV, purple or blue light LED, its preparation method, and light emitting devices incorporating the same. The phosphor contains rare earth, silicon, alkaline-earth metal, halogen, and oxygen, as well as aluminum or gallium. Its General formula of is aLnO.MO.bM'O.fSiO.cAX:dR, wherein Ln is at least one metal element selected from a group consisting of Sc, Y, La, Pr, Nd, Gd, Ho, Yb and Sm; M is at least one metal element selected from a group consisting of Ca, Sr and Ba; M&#x2032; is at least one metal element selected from Al and Ga; A is at least one metal element selected from a group consisting of Li, Na, K, Mg, Ca, Sr and Ba; X is at least one element selected from F and Cl; R is at least one metal element selected from a group consisting of Ce, Eu, Tb and Mn; 0.01&#x2266;a&#x2266;2, 0.35&#x2266;b&#x2266;4, 0.01&#x2266;c&#x2266;1, 0.01&#x2266;d&#x2266;0.3, 0.01&#x2266;f&#x2266;3, 0.6&#x2266;e&#x2266;2.4. The phosphor has broad emitting range, high efficiency, better uniformity and stability. A light emitting device is obtained by incorporating the phosphor into a UV, purple or blue light emitting device.

Phosphor, its preparation method and light emitting devices using the same

A phosphor can be excited by UV, purple or blue light LED, its production and the light emitting devices. The general formula of the phosphor is LnM(O,F):(R,M'), wherein, Ln is at least one metal element selected from a group consisting of Sc, Y, La, Pr, Nd, Gd, Ho, Yb and Sm, 2.6&#x2266;a&#x2266;3.4; M is at least one element selected from a group consisting of B, Al and Ga, 4.5&#x2266;b&#x2266;5.5; R is at least one metal element selected from a group consisting of Ce and Tb; M&#x2032; is at least one metal element selected from a group consisting of Ca, Sr, Ba, Mn and Zn, 0.001&#x2266;x&#x2266;0.4. The phosphor possesses broad emitting range, high efficiency, better uniformity and stability. A light emitting device can be obtained by incorporating this phosphor into a UV, purple or blue light emitting device.

Aluminate phosphor containing bivalence metal elements, its preparation and the light emitting devices incorporating the same

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Beijing, China

Xiaowei Huang