US3812233A - Process for separating cerium concentrate from ores - Google Patents
Process for separating cerium concentrate from ores Download PDFInfo
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- US3812233A US3812233A US00517346A US51734665A US3812233A US 3812233 A US3812233 A US 3812233A US 00517346 A US00517346 A US 00517346A US 51734665 A US51734665 A US 51734665A US 3812233 A US3812233 A US 3812233A
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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
-
- 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
- C01F17/20—Compounds containing only rare earth metals as the metal element
- C01F17/206—Compounds containing only rare earth metals as the metal element oxide or hydroxide being the only anion
- C01F17/224—Oxides or hydroxides of lanthanides
- C01F17/235—Cerium oxides or hydroxides
-
- 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
- C01F17/20—Compounds containing only rare earth metals as the metal element
- C01F17/206—Compounds containing only rare earth metals as the metal element oxide or hydroxide being the only anion
- C01F17/241—Compounds containing only rare earth metals as the metal element oxide or hydroxide being the only anion containing two or more rare earth metals, e.g. NdPrO3 or LaNdPrO3
-
- 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
- C01F17/20—Compounds containing only rare earth metals as the metal element
- C01F17/247—Carbonates
-
- 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
- C01F17/20—Compounds containing only rare earth metals as the metal element
- C01F17/253—Halides
- C01F17/265—Fluorides
-
- 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
- C01F17/20—Compounds containing only rare earth metals as the metal element
- C01F17/253—Halides
- C01F17/271—Chlorides
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01P—INDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS
- C01P2004/00—Particle morphology
- C01P2004/60—Particles characterised by their size
- C01P2004/61—Micrometer sized, i.e. from 1-100 micrometer
Definitions
- This invention relates to the method for the separation of cerium from concentrates of rare earth carbonate ores. In one particular embodiment, it pertains to a process for the separation of cerium concentrates from bastnasite ore that has been subjected to roasting and certain pretreatment processes.
- Bastnasite isan ore that occurs in certain sections of western United States and contains a relatively large amount of rare earth compounds.
- the rare earths referred to herein will be understood as those elements having atomic numbers 57 to 71 inclusive.
- the rare earths of most particular interest are cerium, europium, lanthanum, praseodymium, neodymium, terbium, gadolinium, and Samarium.
- Bastnasite is a rare earth fluocarbonate which contains traces of thorium.
- the mineral is found in deposits in New Mexico, California, Europe and Africa.
- the crude ore as mined in the California deposit contains a substantial percentage of rare earth oxides.
- the mineral contains barite, calcite, silicates, aluminates and ferromagnesian minerals.
- a concentrated bastnasite is commercially available which has the following approximate compositioni Rare Earth Oxides 68 to 70% Fluoride 5 to 8% Si0 1.] to L571 CO to This concentrate is the raw material for my novel process.
- a cerium concentrate can be prepared in a commercial grade with the concurrent recovery of a similarly valuable didymium (mixed rare earth) fraction by controlled acid leaching of the concentrated bastnasite ore.
- My novel process differs from the usual industrial processes in that they normally require total dissolution of the ore by caustic and/or acid attack. My novel process gives valuable products with a minimum of reaction steps.
- the bastnasite ore concentrate is roasted at l,000 to 1,500F. This is normally done by the vendor as a final step in his preparation of the concentrate or it may be done as the first step of my novel process.
- the advantage of roasting the I ore is that it drives off additional carbon dioxide and thus concentrates the ore, the rare earth oxide content increasing to about 90 percent.
- roasting increases the porosity of the ore and at least partially oxidizes the cerium.
- the ore is leached by mixing the ore concentrate with dilute hydrochloric acid.
- the acid concentration must be maintained at less than 5 weight percent. Use of a more concentrated acid results in partial dissolution of the cerium and consequently is to be avoided.
- the acid may be used in concentration as low as 1 weight percent, it is obvious that the rate of reaction is improved by operating at acid concentrations of approximately 3.5 5 weight percent.
- the leaching is normally carried out at atmospheric pressure. Although satisfactory results would be obtained in operation at higher pressures, no economic advantage is achieved by such operation and operation at atmospheric pressure is preferred. Although no effort is made to increase the temperature, the reaction of the hydrochloric acid with the ore concentrate is exothermic so there is an initial increase in the temperature of reaction. This is not objectionable. The reaction can be carried out at temperatures of from 25 to 50C. For obvious economic reasons, operation at room temperature ispreferred.
- the leaching is normally carried out in a weight ratio of ore to dilute acid of l :l to about 1:25.
- the preferred weight ratio is about 1:5 to 1:10.
- the ore is leached for 6 to 24 hours, preferably 12-18 hours.
- cerium concentrate is recovered as the residue from the process andI has a purity of about 80 to 90% based on the formu a:
- the feasibility of the leaching of the roasted bastnasite concentrate with a hydrochloricacid was demonstrated in a run in which 30 grams of the roasted bastnasite percent minus 325 mesh) was transferred to a standard reaction vessel and leached with a solution of 25 ml. of 12 normal (37 weight percent) hydrochloricacid in 250 ml. of water.
- the leaching was carried out by stirring the acid with the bastnasite concentrate for a period of 16 hours. At the end of this time, the material in the reaction vessel was filtered and the filtrate and residues were analyzed. The residue contained approximately CeO /T.O. An analysis of the didymium (mixed rare earth) chloride solution showed the solution contained less than 2% CeO /T.O.
- EXAMPLE II EXAMPLE Ill
- the roasted bastnasite was leached with a weight ratio of bastnasite concentrate to hydrochloric acid of approximately 1.
- the leaching was carried out using the techniques described in Example I. A total of 300 grams of roasted bastnasite was added to and leached with a solution containing 250 ml. of 37 weight percent HCl and 2500 ml. water (concentration approximately 4 weight percent). The leaching was carried out for a period of 22 hours at room temperature. At the end of this time, the slurry was filtered and the filter cake and the filtrate were analyzed. The filtrate was found to have a cerium purity of 90 percent and the rare earth chloride solution contained only 4.8 percent cerium (CeO /T.O.).
- the drawing is a graphical presentation of the above data and provides a general indication of the optimum leach time, under these conditions of temperature, initial acid concentration, and ore/acid ratio.
- EXAMPLE IV The effect of the particle size of the bastnasite ore was investigated in a series of runs in which the bastna-v site ore concentrate was reduced in size to about 5 microns or less and leached using the techniques described in Example I. In the first of these series of runs,
- roasted bastnasite concentrate that had been reduced to a size of about 5 microns and leached with asolytion of 1250 ml. of water containing ml. of hydrochloric acid. This represents a 50 percent increase, relative to Example IV, in acid/ore ratio.
- the leaching was carried out for a period of 20 hours. At the end of this time, the slurry was filtered and the residues and filtrate analyzed. The residue was found to have a CeO purity of about 87 percent.
- the rare earth chloride solution however, contained 12.5% CeO /T.O.
- EXAMPLE VI The effect of acid concentration was investigated in this run. A total of grams of the bastnasite concen- -tratethat had been reduced to 5 micron size was EXAMPLE VII In this example, the effect of the ratio of ore to acid solution was investigated further.
- the ore feed was roasted at l400-1500F., and sized to nominally less than 10 microns. A total of 300 grams of this fine-sized bastnasite was added to and leached with a solution of 250 ml. of hydrochloric acid in 2,500 ml. of water (acid concentration approximately 4 percent). The reaction was carried out for a period of about 20 hours. At the end of this time, the slurry was filtered and the filter cake and solubilized materials analyzed. The cerium concentrate was found to have a Ce0 purity of 88 percent.
- the rare earth chloride solution contained 7% CeO /T.O.
- a process for preparing a cerium concentrate and a non-cerium rare earth chloride solution from a bastnasite ore concentrate which comprises the steps of:
- a process for separating cerium values from noncerium rare earth values from a bastnasite ore concentrate which comprises:
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- General Life Sciences & Earth Sciences (AREA)
- Environmental & Geological Engineering (AREA)
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- Materials Engineering (AREA)
- Mechanical Engineering (AREA)
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- Manufacture And Refinement Of Metals (AREA)
Abstract
A process for separating cerium from the other rare earth values in bastnasite ore by roasting the ore followed by leaching with dilute hydrochlorde acid under carefully controlled conditions.
Description
Duncan PROCESS FOR SEPARATING CERIUM CONCENTRATE FROM ORES [75] Inventor: Larry K. Duncan, Chattanooga,
Tenn.
[73] Assignee: W. R. Grace & C0., New York,
[22] Filed: Dec. 29, 1965 [21] Appl. No.: 517,346
[52] US. Cl. 423/21 [51] Int. Cl. C0lg 57/00, C22b 59/00 [58] Field of Search 23/15, 19, 23, 87; 423/21 [11 3,812,233 May 21, 1974 [56] References Cited UNITED STATES PATENTS 2,327,992 8/!943 Blumenfeld 423/21 Primary Examiner-Herbert T. Carter Attorney, Agent, or Firm-Joseph P. Nigon 57] ABSTRACT A process for separating cerium from the other rare earth values in bastnasite ore by roasting the ore followed by leaching with dilute hydrochlorde acid under carefully controlled conditions.
5 Claims, 1 Drawing Figure PATENIEDIAYZI 974 Amt: mE 53 0. v
INVENTOR LARRY K. DUNCAN S W n O? N a d o O I u I? m. 09
, "1 PROCESS FOR SEPARATING CERIUM CONCENTRATE FROM ORES This invention relates to the method for the separation of cerium from concentrates of rare earth carbonate ores. In one particular embodiment, it pertains to a process for the separation of cerium concentrates from bastnasite ore that has been subjected to roasting and certain pretreatment processes.
Bastnasite isan ore that occurs in certain sections of western United States and contains a relatively large amount of rare earth compounds. The rare earths referred to herein will be understood as those elements having atomic numbers 57 to 71 inclusive. The rare earths of most particular interest are cerium, europium, lanthanum, praseodymium, neodymium, terbium, gadolinium, and Samarium. I
Bastnasite is a rare earth fluocarbonate which contains traces of thorium. The mineral is found in deposits in New Mexico, California, Europe and Africa. The crude ore as mined in the California deposit contains a substantial percentage of rare earth oxides. In addition, the mineral contains barite, calcite, silicates, aluminates and ferromagnesian minerals.
A concentrated bastnasite is commercially available which has the following approximate compositioni Rare Earth Oxides 68 to 70% Fluoride 5 to 8% Si0 1.] to L571 CO to This concentrate is the raw material for my novel process. I have found that a cerium concentrate can be prepared in a commercial grade with the concurrent recovery of a similarly valuable didymium (mixed rare earth) fraction by controlled acid leaching of the concentrated bastnasite ore. My novel process differs from the usual industrial processes in that they normally require total dissolution of the ore by caustic and/or acid attack. My novel process gives valuable products with a minimum of reaction steps.
In the first step of my process, the bastnasite ore concentrate is roasted at l,000 to 1,500F. This is normally done by the vendor as a final step in his preparation of the concentrate or it may be done as the first step of my novel process. The advantage of roasting the I ore is that it drives off additional carbon dioxide and thus concentrates the ore, the rare earth oxide content increasing to about 90 percent. In addition, roasting increases the porosity of the ore and at least partially oxidizes the cerium.
In the second step of my process, the ore is leached by mixing the ore concentrate with dilute hydrochloric acid. The acid concentration must be maintained at less than 5 weight percent. Use of a more concentrated acid results in partial dissolution of the cerium and consequently is to be avoided. Although the acid may be used in concentration as low as 1 weight percent, it is obvious that the rate of reaction is improved by operating at acid concentrations of approximately 3.5 5 weight percent.
The leaching is normally carried out at atmospheric pressure. Although satisfactory results would be obtained in operation at higher pressures, no economic advantage is achieved by such operation and operation at atmospheric pressure is preferred. Although no effort is made to increase the temperature, the reaction of the hydrochloric acid with the ore concentrate is exothermic so there is an initial increase in the temperature of reaction. This is not objectionable. The reaction can be carried out at temperatures of from 25 to 50C. For obvious economic reasons, operation at room temperature ispreferred.
The leaching is normally carried out in a weight ratio of ore to dilute acid of l :l to about 1:25. The preferred weight ratio is about 1:5 to 1:10. The ore is leached for 6 to 24 hours, preferably 12-18 hours.
Both of these products recovered from the bastnasite ore on treatment with the process of my invention, have direct commercial applications. The cerium concentrate is recovered as the residue from the process andI has a purity of about 80 to 90% based on the formu a:
Percent C602 T.O. (Total CeO +rare-earth oxide) Cerium concentrates of this purity constitute a commercial grade for uses such as a specialty glass ingredient or conversion to cerium oxide for glass polishing compounds. This product may also obviously be used as a raw material for production of other and higher pu- EXAMPLE I The feasibility of the leaching of the roasted bastnasite concentrate with a hydrochloricacid was demonstrated in a run in which 30 grams of the roasted bastnasite percent minus 325 mesh) was transferred to a standard reaction vessel and leached with a solution of 25 ml. of 12 normal (37 weight percent) hydrochloricacid in 250 ml. of water. The leaching was carried out by stirring the acid with the bastnasite concentrate for a period of 16 hours. At the end of this time, the material in the reaction vessel was filtered and the filtrate and residues were analyzed. The residue contained approximately CeO /T.O. An analysis of the didymium (mixed rare earth) chloride solution showed the solution contained less than 2% CeO /T.O.
This run demonstrated the utility of my novel process. The hydrochloric acid concentration was about 4 percent and a cerium concentrate containing approximately 75 percent was recovered. The solution recovered was essentially free of cerium.
EXAMPLE II EXAMPLE Ill In this run, the roasted bastnasite was leached with a weight ratio of bastnasite concentrate to hydrochloric acid of approximately 1. The leaching was carried out using the techniques described in Example I. A total of 300 grams of roasted bastnasite was added to and leached with a solution containing 250 ml. of 37 weight percent HCl and 2500 ml. water (concentration approximately 4 weight percent). The leaching was carried out for a period of 22 hours at room temperature. At the end of this time, the slurry was filtered and the filter cake and the filtrate were analyzed. The filtrate was found to have a cerium purity of 90 percent and the rare earth chloride solution contained only 4.8 percent cerium (CeO /T.O.).
This run demonstrates optimum conditions when a bastnasite ore that has not been subjected to the size reduction is used. The purity of the cerium concentrate was high and the didymium chloride solution did not contain an excessive amount of cerium. I This run also indicated the effect of leaching time on the efficiency of the separation. Successive analyses of soluble and insoluble values, during the course of the leaching indicated the relative rate of solubilization of rare earth vs. cerium values:
Under the conditions of this test, with relatively initial high acid concentration, some cerium was dissolved in the first 2 hrs. As rare earth extraction proceeded, and the acidity decreased, most of this cerium reprecipitated into the residue to yield, after dissolution of most of the rare earths, a final rare earth chloride with acceptably low cerium content. Incremental addition of the total acid over the leaching period minimizes this slight initial dissolution of cerium.
The drawing is a graphical presentation of the above data and provides a general indication of the optimum leach time, under these conditions of temperature, initial acid concentration, and ore/acid ratio.
EXAMPLE IV The effect of the particle size of the bastnasite ore was investigated in a series of runs in which the bastna-v site ore concentrate was reduced in size to about 5 microns or less and leached using the techniques described in Example I. In the first of these series of runs,
150 grams of this finely divided roasted bastnasitecon; centrate was leached with a solution of 1250 ml. of water containing 125 ml. of hydrochloric acid (approximately 4 weight percent concentration). The leaching was carried out for a period of about 20 hours. At the end of this time, the products were separated as described above and the rare earth chloride solution analyzed for cerium. The solution was found to contain 5% CeO EXAMPLE V An effort was made to determine the best ratio of fine sized bastnasite to acid. In this run, grams of.
roasted bastnasite concentrate that had been reduced to a size of about 5 microns and leached with asolytion of 1250 ml. of water containing ml. of hydrochloric acid. This represents a 50 percent increase, relative to Example IV, in acid/ore ratio. The leaching was carried out for a period of 20 hours. At the end of this time, the slurry was filtered and the residues and filtrate analyzed. The residue was found to have a CeO purity of about 87 percent. The rare earth chloride solution, however, contained 12.5% CeO /T.O.
EXAMPLE VI The effect of acid concentration was investigated in this run. A total of grams of the bastnasite concen- -tratethat had been reduced to 5 micron size was EXAMPLE VII In this example, the effect of the ratio of ore to acid solution was investigated further. The ore feed was roasted at l400-1500F., and sized to nominally less than 10 microns. A total of 300 grams of this fine-sized bastnasite was added to and leached with a solution of 250 ml. of hydrochloric acid in 2,500 ml. of water (acid concentration approximately 4 percent). The reaction was carried out for a period of about 20 hours. At the end of this time, the slurry was filtered and the filter cake and solubilized materials analyzed. The cerium concentrate was found to have a Ce0 purity of 88 percent. The rare earth chloride solution contained 7% CeO /T.O.
It is apparent from a review of the data presented in Examples IV to VII that advantages are achieved by reducing the size of the roasted bastnasite concentrate prior to the acid leach. When the material was reduced 'in size to below 5 microns and the acid solution kept in excessive? only to the extent that it would decrease the immediate value of the didymium chloride fraction. if the cerium concentrate is the primary product desired, or if the didymium fraction is to be used primarily for feed to other purification operations in which low (i.e., less than -15 percent) cerium content is of minor importance, or if the final leach slurry is to be given a terminal treatment for reprecipitation of soluble cerium, it is obvious that minimizing the dissolution of cerium during leaching would be less important.
Obviously many modifications and variations of the invention may be made without departing from the essence of the scope thereof and only such limitations should be a part of the appended claims.
What is claimed is: 1. A process for preparing a cerium concentrate and a non-cerium rare earth chloride solution from a bastnasite ore concentrate which comprises the steps of:
a. Roasting the ore concentrate at a temperature of about l000 to 1500F for about 1 to 4 hours to drive off a substantial portion of the carbon dioxide, b'. Leaching the roasted ore concentrate with an about 1 to 5 percent hydrochloric acid solution for 6 to 24 hours, c. Filtering and recovering the cerium concentrate andthe non-cerium rare earth chloride solution.
2. The process according to claim 1 wherein the weight ratio of roasted bastnasite ore to hydrochloric acid used in the leaching is from 1 to l to l to 10.
3. The process according to claim 1 wherein the roasted ore is reduced to a size of about 5-10 microns prior to leaching.
4. The process according to claim 1 wherein the leaching is carried out at about 25 to 50C. and atmospheric pressure.
5. A process for separating cerium values from noncerium rare earth values from a bastnasite ore concentrate which comprises:
a. Roasting the ore concentrate at a temperature of about l,000 to l500F. for a time sufficient to drive off a substantial portion of the carbon dioxide whereby cerium values are selectively converted to a form substantially insoluble in aqueous acid leach solution and non-cerium rare earth values are converted to a form soluble in said leach solution,
' b. Leaching the roasted ore concentrate with an about 1 to 5 weight percent hydrochloric acid solution for a time sufficient to solubilize non-cerium rare earth values, and,
c. Separating the leach solution containing noncerium rare earth values from the undissolved concentrate containing cerium values.
Claims (4)
- 2. The process according to claim 1 wherein the weight ratio of roasted bastnasite ore to hydrochloric acid used in the leaching is from 1 to 1 to 1 to 10.
- 3. The process according to claim 1 wherein the roasted ore is reduced to a size of about 5-10 microns prior to leaching.
- 4. The process according to claim 1 wherein the leaching is carried out at about 25* to 50*C. and atmospheric pressure.
- 5. A process for separating cerium values from non-cerium rare earth values from a bastnasite ore concentrate which comprises: a. Roasting the ore concentrate at a temperature of about 1, 000* to 1500*F. for a time sufFicient to drive off a substantial portion of the carbon dioxide whereby cerium values are selectively converted to a form substantially insoluble in aqueous acid leach solution and non-cerium rare earth values are converted to a form soluble in said leach solution, b. Leaching the roasted ore concentrate with an about 1 to 5 weight percent hydrochloric acid solution for a time sufficient to solubilize non-cerium rare earth values, and, c. Separating the leach solution containing non-cerium rare earth values from the undissolved concentrate containing cerium values.
Priority Applications (4)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US00517346A US3812233A (en) | 1965-12-29 | 1965-12-29 | Process for separating cerium concentrate from ores |
| GB49945/66A GB1119720A (en) | 1965-12-29 | 1966-11-08 | Process for separating cerium concentrate from ores |
| DE19661592115 DE1592115A1 (en) | 1965-12-29 | 1966-11-12 | Process for the extraction of cerium concentrates from ores |
| FR86703A FR1532271A (en) | 1965-12-29 | 1966-12-08 | Process for separating concentrates of cerium from ores, and cerium oxide obtained by this process |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US00517346A US3812233A (en) | 1965-12-29 | 1965-12-29 | Process for separating cerium concentrate from ores |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| US3812233A true US3812233A (en) | 1974-05-21 |
Family
ID=24059442
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| US00517346A Expired - Lifetime US3812233A (en) | 1965-12-29 | 1965-12-29 | Process for separating cerium concentrate from ores |
Country Status (3)
| Country | Link |
|---|---|
| US (1) | US3812233A (en) |
| DE (1) | DE1592115A1 (en) |
| GB (1) | GB1119720A (en) |
Cited By (11)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4051219A (en) * | 1975-07-25 | 1977-09-27 | Treibacher Chemische Werke Aktiengesellschaft | Method of preparing fluorine-free rare earth metal compounds from such compounds containing fluorine |
| US4980139A (en) * | 1990-02-28 | 1990-12-25 | Union Oil Company Of California | Method for removing chlorine from a gas stream |
| US5045289A (en) * | 1989-10-04 | 1991-09-03 | Research Corporation Technologies, Inc. | Formation of rare earth carbonates using supercritical carbon dioxide |
| US5049363A (en) * | 1989-08-03 | 1991-09-17 | Westinghouse Electric Corp. | Recovery of scandium, yttrium and lanthanides from titanium ore |
| US5207995A (en) * | 1990-09-19 | 1993-05-04 | Union Oil Company Of California | Recovery of cerium from fluoride-containing ores |
| US5338520A (en) * | 1986-03-19 | 1994-08-16 | Rhone-Poulenc Chimie | Recovery of neodymium/didymium values from bastnaesite ores |
| US5830342A (en) * | 1995-12-13 | 1998-11-03 | Commissariat A L'energie Atomique | Process for the electrocatalytic reducing dissolving of refractory compounds of cerium |
| CN100532595C (en) * | 2006-11-16 | 2009-08-26 | 北京方正稀土科技研究所有限公司 | A kind of bastnaesite decomposition method |
| CN102277484A (en) * | 2011-07-28 | 2011-12-14 | 内蒙古科技大学 | Method for separating and recovering sodium phosphate and sodium fluoride in mixed rare earth concentrate smelting process through alkaline method |
| CN104313318A (en) * | 2014-09-29 | 2015-01-28 | 乐山盛和稀土股份有限公司 | 45-60%-grade rare-earth cerium fluorocarbonate ore leaching technique |
| US11091819B2 (en) | 2013-01-18 | 2021-08-17 | Rare Element Resources Ltd. | Extraction of metals from metallic compounds |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP3415844B2 (en) * | 1990-09-19 | 2003-06-09 | ユニオン オイル カンパニー オブ カリフォルニア | Recovery of cerium from fluoride containing ores |
-
1965
- 1965-12-29 US US00517346A patent/US3812233A/en not_active Expired - Lifetime
-
1966
- 1966-11-08 GB GB49945/66A patent/GB1119720A/en not_active Expired
- 1966-11-12 DE DE19661592115 patent/DE1592115A1/en active Pending
Cited By (12)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4051219A (en) * | 1975-07-25 | 1977-09-27 | Treibacher Chemische Werke Aktiengesellschaft | Method of preparing fluorine-free rare earth metal compounds from such compounds containing fluorine |
| US5338520A (en) * | 1986-03-19 | 1994-08-16 | Rhone-Poulenc Chimie | Recovery of neodymium/didymium values from bastnaesite ores |
| US5049363A (en) * | 1989-08-03 | 1991-09-17 | Westinghouse Electric Corp. | Recovery of scandium, yttrium and lanthanides from titanium ore |
| US5045289A (en) * | 1989-10-04 | 1991-09-03 | Research Corporation Technologies, Inc. | Formation of rare earth carbonates using supercritical carbon dioxide |
| US4980139A (en) * | 1990-02-28 | 1990-12-25 | Union Oil Company Of California | Method for removing chlorine from a gas stream |
| US5207995A (en) * | 1990-09-19 | 1993-05-04 | Union Oil Company Of California | Recovery of cerium from fluoride-containing ores |
| US5433931A (en) * | 1990-09-19 | 1995-07-18 | Union Oil Company Of California | Recovery of cerium |
| US5830342A (en) * | 1995-12-13 | 1998-11-03 | Commissariat A L'energie Atomique | Process for the electrocatalytic reducing dissolving of refractory compounds of cerium |
| CN100532595C (en) * | 2006-11-16 | 2009-08-26 | 北京方正稀土科技研究所有限公司 | A kind of bastnaesite decomposition method |
| CN102277484A (en) * | 2011-07-28 | 2011-12-14 | 内蒙古科技大学 | Method for separating and recovering sodium phosphate and sodium fluoride in mixed rare earth concentrate smelting process through alkaline method |
| US11091819B2 (en) | 2013-01-18 | 2021-08-17 | Rare Element Resources Ltd. | Extraction of metals from metallic compounds |
| CN104313318A (en) * | 2014-09-29 | 2015-01-28 | 乐山盛和稀土股份有限公司 | 45-60%-grade rare-earth cerium fluorocarbonate ore leaching technique |
Also Published As
| Publication number | Publication date |
|---|---|
| GB1119720A (en) | 1968-07-10 |
| DE1592115A1 (en) | 1971-01-21 |
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| AS | Assignment |
Owner name: W.R. GRACE & CO.-CONN. Free format text: MERGER;ASSIGNORS:W.R. GRACE & CO., A CORP. OF CONN. (MERGED INTO);GRACE MERGER CORP., A CORP. OF CONN. (CHANGED TO);REEL/FRAME:004937/0001 Effective date: 19880525 |