CN1119216A - Process for preparing neodymium and neodymium-dysprosium compounds by recovering waste neodymium-iron-boron - Google Patents
Process for preparing neodymium and neodymium-dysprosium compounds by recovering waste neodymium-iron-boron Download PDFInfo
- Publication number
- CN1119216A CN1119216A CN94111454A CN94111454A CN1119216A CN 1119216 A CN1119216 A CN 1119216A CN 94111454 A CN94111454 A CN 94111454A CN 94111454 A CN94111454 A CN 94111454A CN 1119216 A CN1119216 A CN 1119216A
- Authority
- CN
- China
- Prior art keywords
- neodymium
- solution
- acid
- precipitation
- obtains
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
Classifications
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
- Y02P10/00—Technologies related to metal processing
- Y02P10/20—Recycling
Landscapes
- Manufacture And Refinement Of Metals (AREA)
Abstract
The process for recovering and preparing Nd or Nd-Dy compounds from waste Nd-Fe-B alloy features that according to the properties of Nd-Fe-B alloy and its member elements, acid dissolving, precipitation, or extraction separation steps are used for removing non-rare-earth impurities step-by-step to obtain rare-earth oxide. The rare-earth product contains over 98% of total rare-earth content and under 0.2% of Fe content, conforming to requirement of making Nd-Fe-B alloy.
Description
The present invention relates to hydrometallurgy and produce neodymium and neodymium dysprosium compound.
The production of neodymium compound at present is to adopt various rare-earth mineral, and mixed rare-earth oxide and muriate made through pre-treatment (acid is molten), extracting and separating, three steps of aftertreatment (precipitation, calcination).Annual both at home and abroad production of neodymium-iron-boron magnetic material and consumption are very big, the so just unavoidable NdFeB material that gives up in enormous quantities that produces, according to the retrieval, the useless neodymium iron boron of recycling makes neodymium compound and reaches than higher purity, goes back the both economical rational technology of none at present.
The purpose of this invention is to provide and a kind of wherein rare earth element is handled, reclaimed to useless neodymium iron boron, make the processing method of needed single neodymium compound or neodymium dysprosium compound, to remedy the deficiency of the raw material neodymium compound of producing the required rare earth metal of neodymium-iron-boron magnetic material on the market.
Character and composition situation according to neodymium-iron-boron magnetic material self, rare earth element is different with the characteristic of iron boron, the neodymium iron boron that will give up dissolving (hydrochloric acid, sulfuric acid, nitric acid) obtains waste material acid solution (chlorate solution, sulfate liquor, nitrate solution), the present invention adopts following method to handle, to obtain needed rare-earth products:
(1) waste solution adds Sodium sulfate anhydrous.min(99) (Na
2SO
4) carry out double salt precipitation, adding caustic soda (NaOH) alkali after the throw out washing changes, and precipitation of hydroxide adds hydrochloric acid (sulfuric acid, nitric acid), and to carry out acid molten, adds oxalic acid (H
2C
2O
4) or carbon ammonium (NH
4HCO
3) precipitation, the throw out washing filtering at high temperature carries out calcination, the rare earth oxide that obtains reclaiming with throw out then.
(2) the waste material acid solution adds H
2O
2With Fe
2+Be oxidized to Fe
3+, add HN
3H
2O transfers solution PH=3.5~4.5, forms Fe (OH)
3Precipitation, filtration, supernatant liquor carry out oxalic acid precipitation by method (1), make rare earth oxide.
(3) the waste material acid solution adds H
2O
2With Fe
2+Be oxidized to Fe
3+, adopt neutral extraction agent extracting and separating Fe
2+, the earth solution that obtains adds oxalic acid (or carbon ammonium) precipitation, washing filtering, and throw out at high temperature calcination obtains rare earth oxide.
(4) the waste material acid solution directly adds oxalic acid precipitation, adds H with acid solution
2O
2Washing and filtering, throw out is calcination at high temperature, obtains rare earth oxide.
The rare earth acid solution that obtains by method (1) carries out extracting and separating before oxalic acid precipitation separates different rare earth elements contained in the neodymium iron boron waste material and obtains single Neodymium trichloride and Dysprosium trichloride, and then does oxalic acid precipitation by method (1) and make Neodymium trioxide and dysprosium oxide.
The earth solution that obtains by method (3) extracting and separating can further adopt neodymium and the dysprosium that contains in neutrality or the acidic extractant rare-earth separating solution, obtain single Neodymium trichloride and Dysprosium trichloride, add oxalic acid precipitation, washing filtering, throw out calcination at high temperature obtains Neodymium trioxide and dysprosium oxide.
The present invention recycles neodymium iron boron waste material, makes needed rare-earth products, reaches the comprehensive utilization of waste product, and decontamination cuts the waste, and has good economic benefits and social benefit.
Embodiment: waste material (by material: hydrochloric acid<industry 〉=1: 3~5) is added the dissolving with hydrochloric acid groove carry out acid and dissolve, obtain the chloride soln of iron and rare earth, and boron is insoluble to hydrochloric acid, treat all to dissolve after-filtration, filter residue is used to reclaim boron, filtrate is squeezed into setting tank, (by oxalic acid: rare earth content=1.2~1.5: (solution acidity is controlled at [H]=0.01~1N) and stirs and precipitate 1) to add oxalic acid to measure liquor capacity and rare earth concentration, after treating that precipitation is fully also clarified, the siphon supernatant liquor is used to reclaim iron, and throw out is with containing 1~3%H
2O
21~3%Hcl1~3%
2C
2O
4Solution washing 3~5 times, after iron level meets the requirements in the mensuration throw out, filtration obtains rare-earth oxalate, the oxalate earthen bowl of packing into is put into chamber type electric resistance furnace or tunnel furnace, under 850~900 ℃, constant temperature calcination 2-3 hour, cooling is come out of the stove and is obtained oxide compound, plastic bag packaging is as the raw material of electrolytic metal.Whole process flow:
Claims (5)
1, the neodymium iron boron dissolving (hydrochloric acid, sulfuric acid, nitric acid) of will giving up obtains waste material acid solution (chlorate solution, sulfate liquor, nitrate solution), adopts following method to handle, to obtain needed rare-earth products:
(1) waste solution adds Sodium sulfate anhydrous.min(99) (Na
2SO
4) carry out double salt precipitation, adding caustic soda (NaOH) alkali after the throw out washing changes, and precipitation of hydroxide adds hydrochloric acid (sulfuric acid, nitric acid), and to carry out acid molten, adds oxalic acid (H
2C
2O
4) or carbon ammonium (NH
4HCO
3) precipitation, the throw out washing filtering at high temperature carries out calcination, the rare earth oxide that obtains reclaiming with throw out then.
(2) the waste material acid solution adds H
2O
2With Fe
2+Be oxidized to Fe
3+, add HN
3H
2O transfers solution PH=3.5~4.5, forms Fe (OH)
3Precipitation, filtration, supernatant liquor carry out oxalic acid precipitation by method (1), make rare earth oxide.
(3) the waste material acid solution adds H
2O
2With Fe
2+Be oxidized to Fe
3+, adopt neutral extraction agent extracting and separating Fe
2+, the earth solution that obtains adds oxalic acid (or carbon ammonium) precipitation, washing filtering, and throw out at high temperature calcination obtains rare earth oxide.
(4) the waste material acid solution directly adds oxalic acid precipitation, adds H with acid solution
2O
2Washing and filtering, throw out is calcination at high temperature, obtains rare earth oxide.
2, according to (1) described method in the claim 1, the rare earth acid solution that obtains is carried out extracting and separating before oxalic acid precipitation different rare earth elements separation contained in the neodymium iron boron waste material are obtained single Neodymium trichloride and Dysprosium trichloride, and then do oxalic acid precipitation by method (1) and make Neodymium trioxide and dysprosium oxide.
3, according to (3) described method in the claim 1, the earth solution that extracting and separating is obtained can further adopt neodymium and the dysprosium that contains in neutrality or the acidic extractant rare-earth separating solution, obtain single Neodymium trichloride and Dysprosium trichloride, add oxalic acid precipitation, washing filtering, throw out calcination at high temperature obtains Neodymium trioxide and dysprosium oxide.
4, method according to claim 1, throw out is with containing 1~3%H
2O
2, 1~3%Hcl, 1~3%H
2C
2O
4Solution washing 3~5 times.
5, method according to claim 1 is with the calcination 2~3 hours under 800~900 ℃ high temperature of the throw out behind the washing filtering.
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
CN94111454A CN1119216A (en) | 1994-09-22 | 1994-09-22 | Process for preparing neodymium and neodymium-dysprosium compounds by recovering waste neodymium-iron-boron |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
CN94111454A CN1119216A (en) | 1994-09-22 | 1994-09-22 | Process for preparing neodymium and neodymium-dysprosium compounds by recovering waste neodymium-iron-boron |
Publications (1)
Publication Number | Publication Date |
---|---|
CN1119216A true CN1119216A (en) | 1996-03-27 |
Family
ID=5035322
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
CN94111454A Pending CN1119216A (en) | 1994-09-22 | 1994-09-22 | Process for preparing neodymium and neodymium-dysprosium compounds by recovering waste neodymium-iron-boron |
Country Status (1)
Country | Link |
---|---|
CN (1) | CN1119216A (en) |
Cited By (27)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN1077603C (en) * | 1998-05-12 | 2002-01-09 | 住友金属矿山株式会社 | Recovering method of valuable composition from rare earth element-containing material and alloy powder obtained therefrom |
CN1295357C (en) * | 2005-05-08 | 2007-01-17 | 西安西骏新材料有限公司 | Recovery method of valuable element in neodymium iron boron waste material |
CN1321201C (en) * | 2004-08-25 | 2007-06-13 | 日本磁力选矿株式会社 | Method for recovering rear-earth element |
CN102583492A (en) * | 2012-02-20 | 2012-07-18 | 甘肃稀土新材料股份有限公司 | Production process of neodymium oxide with small bulk density |
WO2012113263A1 (en) * | 2011-02-26 | 2012-08-30 | 赣州力赛科新技术有限公司 | Method for removing iron and aluminum from iron-based waste material containing high-value elements through natural oxidation |
CN103093916A (en) * | 2013-02-06 | 2013-05-08 | 南京信息工程大学 | Neodymium iron boron magnetic materials and preparation method of the same |
CN103160681A (en) * | 2013-02-19 | 2013-06-19 | 北京工业大学 | Preprocessing method of preparing neodymium iron boron alloy by using neodymium iron boron grinding-material oil sludge |
CN103160682A (en) * | 2013-02-19 | 2013-06-19 | 北京工业大学 | Preprocessing method of preparing neodymium iron boron alloy by using neodymium iron boron linear-cutting oil sludge |
CN103343233A (en) * | 2013-07-19 | 2013-10-09 | 北京工业大学 | Method for recovering neodymium and iron from neodymium iron boron oil sludge |
CN103343235A (en) * | 2013-07-19 | 2013-10-09 | 北京工业大学 | Method for recovering neodymium and iron from neodymium iron boron oil sludge through two-step co-precipitation |
CN103343234A (en) * | 2013-07-19 | 2013-10-09 | 北京工业大学 | Method for preparing neodymium and iron oxides by using neodymium iron boron oil sludge through regeneration and co-precipitation |
CN103667715A (en) * | 2013-12-17 | 2014-03-26 | 北京工业大学 | Method for recovering Nd (neodymium), Pr (praseodymium), Dy (dysprosium), Co (cobalt) and Fe (iron) simultaneously from NdFeB (neodymium iron boron) oil sludge under C2H2O4-OH system |
CN103911516A (en) * | 2014-03-27 | 2014-07-09 | 全南晶环科技有限责任公司 | Process for extracting neodymium from waste electronic ceramic powder |
CN103917672A (en) * | 2011-11-14 | 2014-07-09 | 住友金属矿山株式会社 | Method for recovering rare earth element |
CN104388711A (en) * | 2014-12-11 | 2015-03-04 | 内蒙古科技大学 | Method for recovering rare earth by leaching rare earth oxide molten slag |
WO2016019044A1 (en) * | 2014-07-29 | 2016-02-04 | Trustees Of The University Of Pennsylvania | Simple chemical method for the separation of rare earth metals |
CN107470640A (en) * | 2017-09-26 | 2017-12-15 | 北京京磁电工科技有限公司 | The waste material of neodymium iron boron magnetic body recycles preparation technology |
CN107758679A (en) * | 2017-10-10 | 2018-03-06 | 北京工业大学 | A kind of technique that boron is reclaimed from waste and old NdFeB material |
CN107794373A (en) * | 2017-11-06 | 2018-03-13 | 王志勇 | The integrated conduct method of the useless magnetic material of neodymium iron boron |
CN108004412A (en) * | 2017-12-28 | 2018-05-08 | 长春工程学院 | A kind of room temperature wet method ozone oxidation goes iron removaling and the equipment and technique of organic matter from neodymium iron boron greasy filth waste material |
CN108018430A (en) * | 2017-12-28 | 2018-05-11 | 长春工程学院 | A kind of device and method of neodymium iron boron powdered scrap room temperature wet oxidation iron removaling |
CN108018429A (en) * | 2017-12-28 | 2018-05-11 | 长春工程学院 | A kind of method that room temperature ultrasound-hydrogen peroxide wet oxidation removes the impurity such as iron removaling and organic matter from neodymium iron boron waste material |
CN108018427A (en) * | 2017-12-28 | 2018-05-11 | 长春工程学院 | A kind of method of room temperature wet method UV-ozone oxidation organics removal from neodymium iron boron greasy filth waste material |
CN108193051A (en) * | 2017-12-28 | 2018-06-22 | 长春工程学院 | A kind of neodymium iron boron powdered scrap room temperature wet method air, ozone secondary oxidation remove the device and method of iron |
CN108559845A (en) * | 2017-12-28 | 2018-09-21 | 长春工程学院 | A kind of method that the oxidation of room temperature wet method ultrasound-ozone removes iron and organic matter from neodymium iron boron greasy filth waste material |
CN110607537A (en) * | 2019-09-26 | 2019-12-24 | 江西理工大学 | Method for synchronously and efficiently extracting rare earth and iron from high-value recycled neodymium iron boron waste |
CN112301220A (en) * | 2020-10-30 | 2021-02-02 | 包头市聚峰稀土有限责任公司 | Method for reducing iron content in rare earth sulfate water leaching solution |
-
1994
- 1994-09-22 CN CN94111454A patent/CN1119216A/en active Pending
Cited By (37)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN1077603C (en) * | 1998-05-12 | 2002-01-09 | 住友金属矿山株式会社 | Recovering method of valuable composition from rare earth element-containing material and alloy powder obtained therefrom |
CN1321201C (en) * | 2004-08-25 | 2007-06-13 | 日本磁力选矿株式会社 | Method for recovering rear-earth element |
CN1295357C (en) * | 2005-05-08 | 2007-01-17 | 西安西骏新材料有限公司 | Recovery method of valuable element in neodymium iron boron waste material |
WO2012113263A1 (en) * | 2011-02-26 | 2012-08-30 | 赣州力赛科新技术有限公司 | Method for removing iron and aluminum from iron-based waste material containing high-value elements through natural oxidation |
CN103917672A (en) * | 2011-11-14 | 2014-07-09 | 住友金属矿山株式会社 | Method for recovering rare earth element |
CN103917672B (en) * | 2011-11-14 | 2016-06-22 | 住友金属矿山株式会社 | The recovery method of rare earth element |
CN102583492A (en) * | 2012-02-20 | 2012-07-18 | 甘肃稀土新材料股份有限公司 | Production process of neodymium oxide with small bulk density |
CN103093916A (en) * | 2013-02-06 | 2013-05-08 | 南京信息工程大学 | Neodymium iron boron magnetic materials and preparation method of the same |
CN103160681A (en) * | 2013-02-19 | 2013-06-19 | 北京工业大学 | Preprocessing method of preparing neodymium iron boron alloy by using neodymium iron boron grinding-material oil sludge |
CN103160682A (en) * | 2013-02-19 | 2013-06-19 | 北京工业大学 | Preprocessing method of preparing neodymium iron boron alloy by using neodymium iron boron linear-cutting oil sludge |
CN103343233A (en) * | 2013-07-19 | 2013-10-09 | 北京工业大学 | Method for recovering neodymium and iron from neodymium iron boron oil sludge |
CN103343234A (en) * | 2013-07-19 | 2013-10-09 | 北京工业大学 | Method for preparing neodymium and iron oxides by using neodymium iron boron oil sludge through regeneration and co-precipitation |
CN103343235A (en) * | 2013-07-19 | 2013-10-09 | 北京工业大学 | Method for recovering neodymium and iron from neodymium iron boron oil sludge through two-step co-precipitation |
CN103343235B (en) * | 2013-07-19 | 2015-03-25 | 北京工业大学 | Method for recovering neodymium and iron from neodymium iron boron oil sludge through two-step co-precipitation |
CN103343233B (en) * | 2013-07-19 | 2015-10-28 | 北京工业大学 | A kind of neodymium iron boron greasy filth reclaims the method for neodymium iron |
CN103667715A (en) * | 2013-12-17 | 2014-03-26 | 北京工业大学 | Method for recovering Nd (neodymium), Pr (praseodymium), Dy (dysprosium), Co (cobalt) and Fe (iron) simultaneously from NdFeB (neodymium iron boron) oil sludge under C2H2O4-OH system |
CN103667715B (en) * | 2013-12-17 | 2016-05-18 | 北京工业大学 | A kind of at C2H2O4Under-OH system, from neodymium iron boron greasy filth, reclaim the method for neodymium, praseodymium, dysprosium, cobalt, iron simultaneously |
CN103911516A (en) * | 2014-03-27 | 2014-07-09 | 全南晶环科技有限责任公司 | Process for extracting neodymium from waste electronic ceramic powder |
CN103911516B (en) * | 2014-03-27 | 2015-10-28 | 全南晶环科技有限责任公司 | A kind of technique extracting neodymium from waste electronic ceramics powder |
WO2016019044A1 (en) * | 2014-07-29 | 2016-02-04 | Trustees Of The University Of Pennsylvania | Simple chemical method for the separation of rare earth metals |
US10704122B2 (en) | 2014-07-29 | 2020-07-07 | The Trustees Of The University Of Pennsylvania | Simple chemical method for the separation of rare earth metals |
CN104388711A (en) * | 2014-12-11 | 2015-03-04 | 内蒙古科技大学 | Method for recovering rare earth by leaching rare earth oxide molten slag |
CN107470640A (en) * | 2017-09-26 | 2017-12-15 | 北京京磁电工科技有限公司 | The waste material of neodymium iron boron magnetic body recycles preparation technology |
CN107470640B (en) * | 2017-09-26 | 2019-10-01 | 北京京磁电工科技有限公司 | The waste material of neodymium iron boron magnetic body recycles preparation process |
CN107758679A (en) * | 2017-10-10 | 2018-03-06 | 北京工业大学 | A kind of technique that boron is reclaimed from waste and old NdFeB material |
CN107758679B (en) * | 2017-10-10 | 2020-01-24 | 北京工业大学 | Process for recovering boron from waste neodymium iron boron material |
CN107794373A (en) * | 2017-11-06 | 2018-03-13 | 王志勇 | The integrated conduct method of the useless magnetic material of neodymium iron boron |
CN107794373B (en) * | 2017-11-06 | 2019-01-22 | 孙东江 | The integrated conduct method of the useless magnetic material of neodymium iron boron |
CN108193051A (en) * | 2017-12-28 | 2018-06-22 | 长春工程学院 | A kind of neodymium iron boron powdered scrap room temperature wet method air, ozone secondary oxidation remove the device and method of iron |
CN108559845A (en) * | 2017-12-28 | 2018-09-21 | 长春工程学院 | A kind of method that the oxidation of room temperature wet method ultrasound-ozone removes iron and organic matter from neodymium iron boron greasy filth waste material |
CN108018427A (en) * | 2017-12-28 | 2018-05-11 | 长春工程学院 | A kind of method of room temperature wet method UV-ozone oxidation organics removal from neodymium iron boron greasy filth waste material |
CN108018429A (en) * | 2017-12-28 | 2018-05-11 | 长春工程学院 | A kind of method that room temperature ultrasound-hydrogen peroxide wet oxidation removes the impurity such as iron removaling and organic matter from neodymium iron boron waste material |
CN108018430A (en) * | 2017-12-28 | 2018-05-11 | 长春工程学院 | A kind of device and method of neodymium iron boron powdered scrap room temperature wet oxidation iron removaling |
CN108004412A (en) * | 2017-12-28 | 2018-05-08 | 长春工程学院 | A kind of room temperature wet method ozone oxidation goes iron removaling and the equipment and technique of organic matter from neodymium iron boron greasy filth waste material |
CN110607537A (en) * | 2019-09-26 | 2019-12-24 | 江西理工大学 | Method for synchronously and efficiently extracting rare earth and iron from high-value recycled neodymium iron boron waste |
CN110607537B (en) * | 2019-09-26 | 2021-02-26 | 江西理工大学 | Method for synchronously and efficiently extracting rare earth and iron from high-value recycled neodymium iron boron waste |
CN112301220A (en) * | 2020-10-30 | 2021-02-02 | 包头市聚峰稀土有限责任公司 | Method for reducing iron content in rare earth sulfate water leaching solution |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
CN1119216A (en) | Process for preparing neodymium and neodymium-dysprosium compounds by recovering waste neodymium-iron-boron | |
CN103374652B (en) | Method for comprehensively recycling rare earth and fluorine in process of treating bastnaesite | |
CN102443701B (en) | Clean metallurgic comprehensive utilization method of iron vitriol slags | |
CN102190325B (en) | Method for recovering rare earth from ionic type rare earth crude ore | |
CN102206755B (en) | Method for separating and recovering valuable elements from neodymium-iron-boron wastes | |
CN1255560C (en) | Process for recovering rare earth from neodymium-ion-boron waste materials | |
CN104775026B (en) | A kind of method that high-purity uranium, thorium and mischmetal are extracted from excellent molten slag | |
US5362459A (en) | Neodymium recovery process | |
CN102277483B (en) | Method for preparing rare earth chloride by using Baiyunebo rare earth concentrate | |
CN103695671B (en) | Reclaim in a kind of spent acid by producing zirconates, the method for purification Scium trioxide powder | |
CN110358923B (en) | Method for extracting indium and recycling zinc oxide smoke dust by using zinc oxide smoke dust | |
CN101532094A (en) | Technology for full-process extracting and separating nickel and cobalt from acid material system with high content of calcium and magnesium impurities | |
CN102011020A (en) | Method for recovering rare earth elements from neodymium-iron-boron wastes | |
CN105256143B (en) | Scandium and the method for other rare earths are extracted from zirconium oxychloride acid pickle | |
CN103290224A (en) | Recovery process for valuable metals in tungsten residues | |
CN101376929A (en) | Method for extracting bismuth from bismuth ore concentrate or material containing bismuth | |
CN102965506B (en) | Method for removing aluminum from rare earth solution by benzoate precipitation method | |
CN103667749A (en) | Method for enriching scandium in anatase raw ore | |
CN109593977A (en) | A method of removal is containing iron ion in neodymium, praseodymium, dysprosium and ferrous solution | |
CN103614563A (en) | Comprehensive recovery and processing method for red mud waste residues and titanium dioxide spent liquor | |
CN109574181A (en) | A kind of method that rare earth oxalate precipitate waste water reclaiming is administered | |
CN103572064A (en) | Method for enriching lead and recovering rare earth from rare earth lead slag | |
CN111485110A (en) | Method for improving utilization rate of valuable elements in rare earth | |
CN103215451A (en) | Recovery method of rare earth elements in ionic rare earth smelting acid dissolution slag | |
US3699208A (en) | Extraction of beryllium from ores |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
C06 | Publication | ||
PB01 | Publication | ||
C01 | Deemed withdrawal of patent application (patent law 1993) | ||
WD01 | Invention patent application deemed withdrawn after publication |