EP3856940A1 - Method for purifying and for concentrating rare earths from phosphogypsum - Google Patents
Method for purifying and for concentrating rare earths from phosphogypsumInfo
- Publication number
- EP3856940A1 EP3856940A1 EP19783383.3A EP19783383A EP3856940A1 EP 3856940 A1 EP3856940 A1 EP 3856940A1 EP 19783383 A EP19783383 A EP 19783383A EP 3856940 A1 EP3856940 A1 EP 3856940A1
- Authority
- EP
- European Patent Office
- Prior art keywords
- phosphogypsum
- leaching
- solution
- rare earths
- evaporation
- 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
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- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22B—PRODUCTION AND REFINING OF METALS; PRETREATMENT OF RAW MATERIALS
- C22B59/00—Obtaining rare earth metals
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- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01F—COMPOUNDS OF THE METALS BERYLLIUM, MAGNESIUM, ALUMINIUM, CALCIUM, STRONTIUM, BARIUM, RADIUM, THORIUM, OR OF THE RARE-EARTH METALS
- C01F17/00—Compounds of rare earth metals
- C01F17/10—Preparation or treatment, e.g. separation or purification
-
- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22B—PRODUCTION AND REFINING OF METALS; PRETREATMENT OF RAW MATERIALS
- C22B3/00—Extraction of metal compounds from ores or concentrates by wet processes
- C22B3/04—Extraction of metal compounds from ores or concentrates by wet processes by leaching
- C22B3/06—Extraction of metal compounds from ores or concentrates by wet processes by leaching in inorganic acid solutions, e.g. with acids generated in situ; in inorganic salt solutions other than ammonium salt solutions
- C22B3/065—Nitric acids or salts thereof
-
- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22B—PRODUCTION AND REFINING OF METALS; PRETREATMENT OF RAW MATERIALS
- C22B3/00—Extraction of metal compounds from ores or concentrates by wet processes
- C22B3/04—Extraction of metal compounds from ores or concentrates by wet processes by leaching
- C22B3/06—Extraction of metal compounds from ores or concentrates by wet processes by leaching in inorganic acid solutions, e.g. with acids generated in situ; in inorganic salt solutions other than ammonium salt solutions
- C22B3/08—Sulfuric acid, other sulfurated acids or salts thereof
-
- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22B—PRODUCTION AND REFINING OF METALS; PRETREATMENT OF RAW MATERIALS
- C22B3/00—Extraction of metal compounds from ores or concentrates by wet processes
- C22B3/04—Extraction of metal compounds from ores or concentrates by wet processes by leaching
- C22B3/06—Extraction of metal compounds from ores or concentrates by wet processes by leaching in inorganic acid solutions, e.g. with acids generated in situ; in inorganic salt solutions other than ammonium salt solutions
- C22B3/10—Hydrochloric acid, other halogenated acids or salts thereof
-
- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22B—PRODUCTION AND REFINING OF METALS; PRETREATMENT OF RAW MATERIALS
- C22B3/00—Extraction of metal compounds from ores or concentrates by wet processes
- C22B3/20—Treatment or purification of solutions, e.g. obtained by leaching
- C22B3/44—Treatment or purification of solutions, e.g. obtained by leaching by chemical processes
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- 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
Definitions
- the present invention relates to the field of leaching of phosphogypsum obtained by the action of phosphoric acid on a phosphate rock.
- the invention relates in particular to the leaching of phosphogypsum as well as the resulting leaching solution and the chemical treatment of the leaching solution.
- phosphogypsum is a side product of the wet phosphoric acid production reaction, this process being the most commonly used process for the production of phosphoric acid.
- phosphate deposits contain varied contents of rare earths, these contents being relatively low, generally less than 1% by weight of rare earths relative to the weight of phosphate rock, or even often less than 0.1% by weight as in the case of sedimentary phosphate.
- Rare earths are of particular interest since their physico-chemical properties make them materials of choice in various applications such as optics (lighting, radiography), mechanics (due to their high hardness), and magnetic (manufacture of 'permanent magnets).
- the leaching mixture comprises a solid phase mainly composed of phosphogypsum and a liquid phase containing the rare earths initially present in the phosphogypsum. The whole point is therefore to improve the leaching in order to increase the efficiency of extraction of rare earths from the phosphogypsum and thus the yield of rare earths.
- the document CN 104903476 describes a process for extracting rare earths from a solid ore or from a secondary product of ore processing such as phosphogypsum.
- This process consists in grinding the initial solid compound to obtain solid elements of a size less than 100 ⁇ m, then in leaching by the action of a mixture of sulfuric acid and nitric acid. on the crushed solid elements.
- the leaching is carried out under conditions according to which the sulfuric acid and the nitric acid are in respective mass proportions of between 6: 1 and 1: 1, the liquid / solid mass ratio of the suspension is between 2: 1 and 6: 1, and the acid mixture is at a concentration of less than 15% by weight.
- This process provides a rare earth leaching yield greater than 76%.
- Document WO201 1/008137 proposes a process for extracting rare earths from phosphogypsum by leaching with a mixture of sulfuric acid and nitric acid whose mass ratio is 3.2: 1, 2.
- the liquid / solid mass ratio of the suspension is 4: 5, and the acid mixture is at a concentration of between 1% and 3% by weight.
- This process provides a yield of around 81%. Note, however, that the extraction of rare earths according to the process described is accompanied by a solubilization of the phosphogypsum, which affects the quality of the rare earths obtained.
- Document WO2013060689 describes a process for extracting rare earths from calcium sulphate. This process is based on a step of maturing calcium sulphate hemihydrate containing rare earths with crystallization of calcium sulphate dihydrate by capturing water or residual moisture. Leaching with sulfuric acid of the calcium sulphate dihydrate is then carried out, with a mass ratio between the sulfuric acid and the calcium sulphate of between 0.15 and 0.35. This process makes it possible to obtain a yield greater than 80%.
- the methods described in the documents presented above aim to increase the efficiency of extraction of rare earths from calcium sulfate, and thus the yield of rare earths from this extraction.
- the phosphogypsum obtained by the action of phosphoric acid on a phosphate rock comprises a high content of impurities, and very particularly a high content of mineral impurities due to its mineral origin.
- the object of the invention is therefore to remedy the drawbacks of the prior art by proposing a process for the purification and concentration of the rare earths initially contained in phosphogypsum, making it possible to reduce the content of mineral impurities and to increase the content of earths. rare in the leach solution.
- the invention provides a process for the purification and concentration of the rare earths contained in phosphogypsum, characterized in that it comprises the following steps:
- the proposed process has the following different characteristics taken alone or according to their technically possible combinations:
- the method further comprises a step a 0 ) of washing the phosphogypsum with a sulphated solution produced before step a) of leaching;
- the sulphated solution used in step a 0 ) is a potassium sulphate solution, a sodium sulphate solution, a calcium sulphate solution, or a mixture thereof; the sulphate content in the sulphated solution is less than or equal to 25%, preferably less than or equal to 20%, relative to the total mass of sulphated solution; washing step a 0 ) is carried out at a temperature between 20 ° C and 60 ° C, preferably at a temperature between 20 ° C and 40 ° C, and more preferably at a temperature between 25 ° C and 30 ° C;
- the method further comprises a step d) of evaporation of the leach solution obtained in step c) in order to concentrate the rare earths present in the leach solution;
- evaporation step d) comprises at least two evaporation steps, including a first evaporation step, the evaporation rate of which is between 20% and 40%, preferably between 20% and 30%, and a second evaporation step, the evaporation rate of which is adjusted as a function of that of the first evaporation step in order to obtain an overall evaporation rate less than or equal to 51%;
- the method further comprises a step e) of treating the leaching solution obtained in step c) or in step d) with ammonia in order to neutralize the leaching acid, to obtain a leaching solution whose pH is greater than or equal to 1;
- the method also comprises a step d) of evaporation of the leach solution obtained in step c) in order to concentrate the rare earths present in the leach solution;
- the reducing agent is added to the phosphogypsum or to the leaching mixture at a content of between 2 g / kg and 20 g / kg, preferably between 5 g / kg and 15 g / kg, relative to the mass of phosphogypsum implementation in the process.
- the process described makes it possible to extract the rare earths contained in phosphogypsum by leaching, the phosphogypsum being previously obtained by the action of sulfuric acid on a phosphate rock, then to purify, that is to say to reduce the impurities, and to concentrate the leach solution in rare earths. Consequently, the process makes it possible to obtain the rare earths from the leaching solution.
- An optional first step a 0 ) consists in treating the phosphogypsum with a sulphated solution in order to carry out a washing of the phosphogypsum.
- This washing makes it possible to roughly remove organic and / or mineral impurities from the process for obtaining phosphogypsum.
- washing makes it possible to remove mineral impurities originating from the phosphate rock from which the phosphogypsum is derived and organic impurities originating from the sulfuric acid which served to attack the phosphate rock.
- Suitable sulfated solutions are potassium sulfate, sodium sulfate, calcium sulfate, or a mixture thereof.
- the sulphated solution preferably has a mass concentration of sulphate (mass titre) less than or equal to 25%, preferably less than or equal to 20%.
- the step of treating the phosphogypsum with the sulphated solution is carried out at a temperature between 20 ° C and 60 ° C, preferably between 20 ° C and 40 ° C, and more preferably between 25 ° C and 30 ° C.
- a liquid solid separation makes it possible to recover the phosphogypsum washed in the solid phase.
- the phosphogypsum is treated with a solution of a strong acid by leaching to form a leaching mixture, in the presence of an oxidizing agent and / or a reducing agent.
- the strong acid solution used can be in particular a sulfuric acid solution, a hydrochloric acid solution, or a nitric acid solution, or a mixture of acids and in particular of one or more of the acids mentioned above. .
- the phosphogypsum can be treated with a solution of a strong acid in the presence of one or more oxidizing agent (s), or in the presence of one or more reducing agent (s). , or in the presence of both one or more oxidizing agent (s) and one or more reducing agent (s).
- the oxidizing agent increases the solubility of the rare earths in the leaching mixture. More specifically, the phosphogypsum initially appears in the form of crystals. The attack of the phosphogypsum by the strong acid degrades the structure of the phosphogypsum crystals, so that part of the rare earths initially contained in the phosphogypsum passes incidentally from the phosphogypsum in the leaching mixture, and in particular in the solution. leaching in which they are soluble. The oxidizing agent makes it possible to further improve the extraction of rare earths from the phosphogypsum crystals in order to pass them into the liquid phase in the leaching solution.
- the oxidizing agent can be added to the phosphogypsum, optionally washed, before the addition of the strong leaching acid, or else in the leaching mixture.
- the oxidizing agent is added to the leaching mixture, it is added after a mixing time of between 5 minutes and 60 minutes, and more preferably between 15 minutes and 30 minutes.
- the oxidizing agent is chosen from: sodium chlorate, potassium chlorate, sodium perchlorate, and hydrogen peroxide. It is also possible to use several oxidizing agents, and in particular several of the oxidizing agents mentioned above.
- the content of the oxidizing agent in the leaching mixture is between 5 g / kg and 25 g / kg, and preferably between 10 g / kg and 20 g / kg relative to the total weight of the leaching mixture. .
- the reducing agent makes it possible to reduce the solubility of the mineral impurities contained in the leaching solution.
- the reducing agent promotes the precipitation of mineral impurities in order to pass them into the solid phase. The subsequent removal of impurities by solid liquid separation is then possible and effective.
- the reducing agent can be added to the phosphogypsum, optionally washed, prior to the addition of the strong leaching acid, or alternatively in the leaching suspension after the addition of the strong acid.
- a mixing time of the phosphogypsum and the strong acid of between 5 minutes and 60 minutes, and more preferably between 15 minutes and 30 minutes.
- the reducing agent is chosen from: ferrous sulphate, iron powder, and metallic zinc. It is also possible to use several reducing agents, and in particular several of the reducing agents mentioned above.
- the mass concentration of the reducing agent in the leach suspension is between 2 g / kg and 20 g / kg, preferably between 5 g / kg and 15 g / kg, and more preferably at a concentration mass approximately equal to 10 g / kg, relative to the total weight of the leach suspension.
- the mixing temperature is preferably carried out at a temperature between 20 ° C and 60 ° C, preferably between 20 ° C and 40 ° C, and more preferably between 25 ° C and 30 ° C.
- a temperature between 20 ° C and 60 ° C, preferably between 20 ° C and 40 ° C, and more preferably between 25 ° C and 30 ° C.
- a solid / liquid separation for example by filtration, makes it possible to separate the solid phase containing the phosphogypsum and the impurities passed from the leach solution in the solid phase, from the liquid phase formed from the solution.
- leaching solution containing rare earths and strong leaching acid.
- the leach solution is then evaporated in order to concentrate it in rare earths. Evaporation makes it possible to eliminate volatile chemical species from the solution, in particular certain volatile impurities.
- the evaporation is carried out so as to obtain an evaporation rate of less than 60%, and preferably less than 51%.
- the evaporation of the leaching solution comprises two stages of evaporation. This removes more volatile impurities from the leach solution.
- Evaporation thus advantageously comprises a first evaporation step, the evaporation rate of which is between 20% and 40%, preferably between 20% and 30%, and a second evaporation step, the evaporation rate of which is adjusted according to that of the first evaporation step in order to obtain an overall evaporation rate less than or equal to 51%.
- the concentrated solution obtained is neutralized with ammonia to a pH approximately equal to 1. It is possible to use gaseous ammonia (NH 3 gas ) or else a solution aqueous ammonia (Nh ⁇ aqueous ) ⁇
- an oxalic acid solution is added to the leaching solution in order to precipitate the rare earths, the latter being then recovered by solid / liquid separation and optionally purified by any suitable subsequent chemical purification treatment.
- the process which has just been described makes it possible to increase the mass concentration of rare earths in the leaching solution thanks to the presence of the oxidizing agent making it possible to dissolve the rare earths by passing them from the phosphogypsum to the leaching solution.
- the mass concentration of mineral impurities in the leach solution is reduced by virtue of the presence of the reducing agent which makes it possible to reduce the solubility of the impurities and to cause them to precipitate out of the leach solution.
- the process makes it possible to obtain a leaching solution and consequently a final product of rare earths having an amount of rare earths increased and a quantity of mineral impurities reduced compared to the processes of the state of the art, while retaining a good reaction yield.
- Protocol 1 In 800 ml of sulfuric acid of normality equal to 2, 200 g of phosphogypsum are mixed, then sodium chlorate is added at a content of 15 g / kg relative to the weight of the leaching mixture. Before being mixed with sulfuric acid, the phosphogypsum is washed with a sulphated solution with a mass concentration of sulphate equal to 20%.
- powdered iron is introduced into the leaching mixture in a content of 10 g / kg relative to the weight of the leaching mixture, then mixing of the leaching suspension is continued for approximately 4 hours. The solid and liquid phases are then separated, and the leach solution is evaporated.
- protocol 1 For protocol 1, four tests are carried out (1), (2), (3) and (4) in Table I below with the operating conditions and the quantities of impurities and rare earths obtained.
- Rare Earth AP (mg / kg): the content by weight of Rare Earth in the initial phosphogypsum after washing with the sulfated solution, in mg / kg.
- - CaO (mg / L): the mass concentration of residual calcium oxide CaO, originating from the reaction for obtaining phosphoric acid (mineral impurity), in the leaching solution after evaporation, in mg / L.
- - Rare Earth in AV solution (mg / L): the mass concentration of Rare Earth in the leaching solution before evaporation, in mg / L.
- the rare earth content in the phosphogypsum goes from 378 mg / kg before washing to 401 mg / kg after washing for tests 1 and 2, while it remains of course equal to 367 mg / kg for tests 3 and 4 without washing.
- the rare earth content in phosphogypsum goes from 398 mg / kg before washing to 442 mg / kg after washing for test 1 and to 421 mg / kg for test 2, while it remains of course equal to 398 mg / kg for tests 3 and 4 without washing.
- the content by weight of rare earths in the phosphogypsum after washing depends on the process temperature.
- the rare earth content in the phosphogypsum after washing is 401 mg / kg.
- washing cold, at 25 ° C, or hot, at 60 ° C makes it possible to increase the content of rare earths and to decrease the content of impurities with as much efficiency. This is due to the fact that the impurities present in the phosphogypsum are soluble in the sulphated solution both hot and cold.
- the rare earth content in the phosphogypsum after washing is equal to 442 mg / kg compared to only 421 mg / kg for a temperature of 60 ° C in test 2 .
- Washing at 25 ° C is more effective here. This is due to the fact that the impurities present in the phosphogypsum are mainly soluble in the cold sulphated solution, and mainly soluble in hot.
- the content by weight of phosphorus pentoxide P 2 0 5 and the mass concentration of calcium oxide CaO are lower at a process temperature of 25 ° C. than at a process temperature of 60 ° C.
- tests 1 and 2 We compare the tests with washing (tests 1 and 2) and then the tests without washing (tests 3 and 4).
- the content by weight of P 2 0 5 and the mass concentration of calcium oxide CaO are equal to 1.2% and 1.3 mg / L, respectively. against 1.5% and 2.4 mg / L respectively for a temperature of 60 ° C in test 2.
- the content by weight of P 2 0 5 and the mass concentration of calcium oxide CaO are equal to 7% and 19 mg / L respectively, against 9% and 26 mg / L respectively for a temperature of 60 ° C in test 4.
- tests 1 and 2 We compare the tests with washing (tests 1 and 2) and then the tests without washing (tests 3 and 4).
- the content by weight of P 2 0 5 and the mass concentration of calcium oxide CaO are equal to 3.61% and 7.32 mg / L respectively, against respectively 4.93% and 8.6 mg / L for a temperature of 60 ° C in test 2.
- tests 1 and 3 are compared with each other, then the tests at 60 ° C (tests 2 and 4).
- the mass concentrations of rare earths in solution before and after evaporation are respectively 58.32 mg / L and 97.20 mg / L in test 1 against only 27.4 mg / L and 45.67 mg / L in test 3.
- the mass concentrations of rare earths in solution before and after evaporation are respectively 53.81 mg / L and 89.70 mg / L in test 2 against only 19 mg / L and 31, 67 mg / L in test 4.
- tests 1 and 3 are compared with each other, then the tests at 60 ° C (tests 2 and 4).
- the mass concentrations of rare earths in solution before and after evaporation are respectively 176 mg / L and 246.4 mg / L in test 1 against only 108 mg / L and 151, 2 mg / L in test 3.
- the mass concentrations of the rare earths in solution before and after evaporation are respectively 179 mg / L and 260 mg / L in test 2 against only 1 13 mg / L and 158.2 mg / L in test 4.
- the increase in the mass concentration of rare earths in the leach solution is due to the presence of the oxidizing agent which increases the solubilization of rare earths in the leach solution. It is also noted that, whatever the process temperature, the presence of a reducing agent in the leach suspension results in a reduction in the content of impurities in the leach solution obtained.
- tests 1 and 3 are compared with each other, then the tests at 60 ° C (tests 2 and 4).
- the P 2 0 5 content and the mass concentration of CaO are respectively 1, 2% and 1, 3 mg / L in test 1 against 7% and 19 mg / L at trial 3.
- the P 2 0 5 content and the mass concentration of CaO are respectively 1, 5% and 2.4 mg / L in test 2 against 9% and 26 mg / L in test 4.
- tests 1 and 3 are compared with each other, then the tests at 60 ° C (tests 2 and 4).
- the P 2 0 5 content and the mass concentration of CaO are respectively 3.61% and 7.32 mg / L in test 1 against 9.42% and 28, 32 mg / L in test 3.
- the P 2 0 5 content and the mass concentration of CaO are respectively 4.93% and 8.6 mg / L in test 2 against 12.1% and 31 mg / L in test 4.
- the decrease in the P 2 0 5 content and the mass concentration of CaO in the leaching solution is due to the presence of the reducing agent which decreases the solubilization P 2 0 5 and CaO in the leaching solution.
- the mass concentration of the rare earths in the leaching solution goes from, before evaporation to after evaporation, from 58.32 mg / L to 97.20 mg / L for the trial 1, from 53.81 mg / L to 89.70 mg / L for trial 2, from 27.4 mg / L to 45.67 mg / L in trial 3, and from 19 mg / L to 31, 67 mg / L in test 4.
- the mass concentration of rare earths in the leaching solution changes, from before evaporation to after evaporation, from 176 mg / L to 246.4 mg / L for test 1 , from 179 mg / L to 260 mg / L for test 2, from 108 mg / L to 151, 2 mg / L for test 3, and from 1 13 mg / L to 158.2 mg / L at test 4.
- the evaporation step thus makes it possible to concentrate the leaching solution in rare earths, and to eliminate the volatile chemical species remaining after leaching, and in particular the volatile impurities, from the leaching solution.
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- Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Organic Chemistry (AREA)
- Life Sciences & Earth Sciences (AREA)
- Geology (AREA)
- Manufacturing & Machinery (AREA)
- Materials Engineering (AREA)
- Mechanical Engineering (AREA)
- Metallurgy (AREA)
- Environmental & Geological Engineering (AREA)
- General Life Sciences & Earth Sciences (AREA)
- Geochemistry & Mineralogy (AREA)
- Inorganic Chemistry (AREA)
- General Chemical & Material Sciences (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Analytical Chemistry (AREA)
- Manufacture And Refinement Of Metals (AREA)
- Compounds Of Alkaline-Earth Elements, Aluminum Or Rare-Earth Metals (AREA)
- Extraction Or Liquid Replacement (AREA)
- Processing Of Solid Wastes (AREA)
Abstract
Description
Claims
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
FR1858946A FR3086672B1 (en) | 2018-09-28 | 2018-09-28 | PROCESS FOR PURIFICATION AND CONCENTRATION OF RARE EARTHS FROM PHOSPHOGYPSE |
PCT/MA2019/000008 WO2020067856A1 (en) | 2018-09-28 | 2019-09-30 | Method for purifying and for concentrating rare earths from phosphogypsum |
Publications (1)
Publication Number | Publication Date |
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EP3856940A1 true EP3856940A1 (en) | 2021-08-04 |
Family
ID=65243971
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
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EP19783383.3A Pending EP3856940A1 (en) | 2018-09-28 | 2019-09-30 | Method for purifying and for concentrating rare earths from phosphogypsum |
Country Status (8)
Country | Link |
---|---|
US (1) | US20210388466A1 (en) |
EP (1) | EP3856940A1 (en) |
CN (1) | CN112771185B (en) |
FR (1) | FR3086672B1 (en) |
IL (1) | IL281830A (en) |
JO (1) | JOP20210055A1 (en) |
MA (1) | MA53725A (en) |
WO (1) | WO2020067856A1 (en) |
Families Citing this family (2)
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DE102020100260A1 (en) * | 2020-01-08 | 2021-07-08 | Thyssenkrupp Ag | Integrated process for the production of sulfuric acid process-suitable sulfur dioxide quality from calcium sulfate / phosphogypsum from phosphoric acid production |
FR3140379A1 (en) | 2022-09-30 | 2024-04-05 | Universite Mohamed Vi Polytechnique | Process for recovering rare earths and calcium sulfate contained in phosphogypsum |
Family Cites Families (8)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
FR2652076B1 (en) * | 1989-09-20 | 1992-03-20 | Rhone Poulenc Chimie | METHOD FOR RECOVERING RARE EARTH VALUES IN THE GYPSES. |
RU2293781C1 (en) * | 2005-07-04 | 2007-02-20 | Институт химии и технологии редких элементов и минерального сырья им. И.В. Тананаева Кольского научного центра Российской академии наук | Method of recovering rare-earth elements from phosphogypsum |
CN101597688A (en) * | 2008-06-03 | 2009-12-09 | 贵州光大能源发展有限公司 | From phosphogypsum, reclaim a kind of method of rare earth |
RU2412265C1 (en) | 2009-07-16 | 2011-02-20 | Закрытое Акционерное Общество "Твин Трейдинг Компани" | Procedure for extraction of rare earth elements from phospho-gypsum |
NO2771280T3 (en) | 2011-10-24 | 2018-07-21 | ||
RU2519692C1 (en) * | 2012-11-12 | 2014-06-20 | Закрытое Акционерное Общество "Твин Трейдинг Компани" | Extraction of rare-earth elements from hard materials containing rare-earth metals |
RU2528573C1 (en) * | 2013-03-05 | 2014-09-20 | Открытое акционерное общество "Объединенная химическая компания "УРАЛХИМ" | Method of extracting rare-earth metals and producing gypsum plaster from phosphogypsum hemihydrate |
CN107513620B (en) * | 2017-08-30 | 2021-07-09 | 赣州齐畅新材料有限公司 | Process method for extracting rare earth oxide from fluorescent powder waste |
-
2018
- 2018-09-28 FR FR1858946A patent/FR3086672B1/en active Active
-
2019
- 2019-09-30 CN CN201980063988.7A patent/CN112771185B/en active Active
- 2019-09-30 EP EP19783383.3A patent/EP3856940A1/en active Pending
- 2019-09-30 WO PCT/MA2019/000008 patent/WO2020067856A1/en active Application Filing
- 2019-09-30 US US17/279,932 patent/US20210388466A1/en active Pending
- 2019-09-30 JO JOP/2021/0055A patent/JOP20210055A1/en unknown
- 2019-09-30 MA MA053725A patent/MA53725A/en unknown
-
2021
- 2021-03-25 IL IL281830A patent/IL281830A/en unknown
Also Published As
Publication number | Publication date |
---|---|
JOP20210055A1 (en) | 2021-03-24 |
MA53725A (en) | 2022-01-05 |
CN112771185B (en) | 2023-04-11 |
FR3086672A1 (en) | 2020-04-03 |
CN112771185A (en) | 2021-05-07 |
WO2020067856A1 (en) | 2020-04-02 |
FR3086672B1 (en) | 2020-11-13 |
IL281830A (en) | 2021-05-31 |
US20210388466A1 (en) | 2021-12-16 |
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