# US 9,869,005 B2 · Processes for rare earths recovery from wet-process phosphoric acid

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- Number: US 9,869,005 B2
- Document ID: US9869005B2
- Status: Granted
- Kind: B2
- Application number: 14/416,267
- Filed: 2013-07-21
- Published: 2015-06-18
- Granted: 2018-01-16
- Earliest claimed: 2012-07-21
- Assignees: K-Technologies, Inc.
- Applicants: K-Technologies, Inc.
- Inventors: William W. Berry; Thomas E. Baroody
- Web page: https://patentgrep.com/patent/US9869005B2

## CPC

- C22B 59/00: Obtaining rare earth metals
- B01J 39/05: in the strongly acidic form
- B01J 39/20: obtained by reactions only involving unsaturated carbon-to-carbon bonds
- B01J 45/00: Ion-exchange in which a complex or a chelate is formed; Use of material as complex or chelate forming ion-exchangers; Treatment of material for improving the complex or chelate forming ion-exchange properties (ion-exchange chromatography processes B01D15/36)
- B01J 47/026: using columns or beds of different ion exchange materials in series
- B01J 49/06: containing cationic exchangers
- B01J 49/53: for cationic exchangers
- C01F 17/13: by using ion exchange resins, e.g. chelate resins
- C01F 17/224: Oxides or hydroxides of lanthanides
- C01F 17/282: Sulfates
- C22B 3/06: in inorganic acid solutions {, e.g. with acids generated in situ; in inorganic salt solutions other than ammonium salt solutions}
- C22B 3/42: by ion-exchange extraction
- Y02P 10/20: Recycling
- C22B: PRODUCTION AND REFINING OF METALS (electrolytic C25); PRETREATMENT OF RAW MATERIALS
- B01J: CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
- C01F: COMPOUNDS OF THE METALS BERYLLIUM, MAGNESIUM, ALUMINIUM, CALCIUM, STRONTIUM, BARIUM, RADIUM, THORIUM, OR OF THE RARE-EARTH METALS (metal hydrides {monoborane, diborane or addition complexes thereof} C01B6/00; salts of oxyacids of halogens C01B11/00; peroxides, salts of peroxyacids C01B15/00; sulfides or polysulfides of magnesium, calcium, strontium, or barium C01B17/42; thiosulfates, dithionites, polythionates C01B17/64; compounds containing selenium or tellurium C01B19/00; binary compounds of nitrogen with metals C01B21/06; azides C01B21/08; {compounds other than ammonia or cyanogen containing nitrogen and non-metals and optionally metals C01B21/082; amides or imides of silicon C01B21/087}; metal {imides or} amides C01B21/092, {C01B21/0923}; nitrites C01B21/50; {compounds of noble gases C01B23/0005}; phosphides C01B25/08; salts of oxyacids of phosphorus C01B25/16; carbides C01B32/90; compounds containing silicon C01B33/00; compounds containing boron C01B35/00; compounds having molecular sieve properties but not having base-exchange properties C01B37/00; compounds having molecular sieve and base-exchange properties, e.g. crystalline zeolites, C01B39/00; cyanides C01C3/08; salts of cyanic acid C01C3/14; salts of cyanamide C01C3/16; thiocyanates C01C3/20; {double sulfates of magnesium with sodium or potassium C01D5/12; with other alkali metals C01D15/00, C01D17/00})
- Y02P: CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS

## Abstract

In alternative embodiments, the invention provides processes and methods for extracting and recovering rare earth materials from a wet-process phosphoric acid using one or more continuous ion exchange resin systems. In alternative embodiments, the method is particularly suited for use in extracting and recovering multiple rare earth materials present in low concentrations contained in wet-process phosphoric acid.

## Claims

### Claim 1

A method for the removal of a rare earth component, or a mixture of rare earth components, and one or more minor element components or mixture of minor element components, from a wet-process phosphoric acid, and subsequently separating the rare earth components or the mixture of rare earth components from the one or more minor element components or the mixture of minor element components,
the method comprising use of two or more continuous ion exchange systems comprising a strong cationic exchange resin, comprising:
(a) providing a phosphoric acid solution comprising:
(i) the rare earth components or the mixture of rare earth components and the one or more minor element components, or the mixture of minor element components,
(ii) a solution comprising a phosphoric acid and the rare earth components or the mixture of rare earth components and the one or more minor element components or the mixture of minor element components, or
(iii) a phos-acid feedstock comprising the rare earth components or the mixture of rare earth components and the one or more minor element components or the mixture of minor element components;
(b) providing:
(1) a first continuous ion exchange system comprising a strong cationic exchange resin capable of binding:
(i) the rare earth components, or
the mixture of rare earth components and
(ii) the one or more minor element components or the mixture of minor element components,
wherein the strong cationic exchange resin is in the H+ form, and
(2) a second continuous ion exchange system comprising a strong cationic exchange resin with a specific affinity for a rare earth component, or mixture of rare earth components;
(c) providing an acid regeneration solution comprising a strong acid;
(d) applying the provided phosphoric acid solution of (a), to the first continuous ion exchange system comprising a strong cationic exchange resin of (b) under conditions that cause the rare earth components, or the mixture of rare earth components, and the one or more minor element components or the mixture of minor element components, to remain on the first continuous ion exchange system comprising a strong cationic exchange resin;
(e) removing the rare earth components, or the mixture of rare earth components and the one or more minor element components or the mixture of minor element components, or eluting the rare earth components, or the mixture of rare earth components and the one or more minor element components or the mixture of minor element components, from the first continuous ion exchange system comprising a strong cationic exchange resin using the acid regeneration solution, resulting in or thereby producing an acid regeneration solution eluant containing or comprising the rare earth components, or the mixture of rare earth components, and the one or more minor element components or the mixture of minor element components; and
(f) contacting the acid regeneration solution eluant comprising as eluates the rare earth components, or the mixture of rare earth components, and the one or more minor element components or the mixture of minor element components, with the second continuous ion exchange system comprising a strong cationic exchange resin with a specific affinity for a rare earth component, or mixture of rare earth components,
wherein the second continuous ion exchange system comprising a strong cationic exchange resin binds the rare earth components, or the mixture of rare earth components, and separates the rare earth components, or the mixture of rare earth components, from the one or more minor element components or the mixture of minor element components,
wherein the one or more minor element components or the mixture of minor element components comprise:
iron, aluminum and/or magnesium or their respective oxides.

### Claim 2 (depends on 1)

The method of claim 1, wherein the provided phosphoric acid solution is first treated, or pre-treated, with a clarification process or a filtering process, or a clarification aid in order to remove suspended solids.

### Claim 3 (depends on 1)

The method of claim 1, further comprising selectively removing or eluting the rare earth components, or mixture of rare earth components, from the second continuous ion exchange system comprising a strong cationic exchange resin resulting in a second eluate containing substantially only the rare earth components with no or minimal minor element components, or mixture of minor element components.

### Claim 4 (depends on 3)

The method of claim 3, further comprising contacting the second eluate with a third continuous ion exchange system comprising a strong cationic exchange resin operating in a chromatographic mode,
wherein the strong cationic exchange resin comprises a resin with a specific affinity for one or more rare earth components, or mixtures of rare earth components,
and wherein the third continuous ion exchange system comprising a strong cationic exchange resin operating in a chromatographic mode selectively binds one or more rare earth components, or mixtures of rare earth components, and separates the rare earth components, or the mixtures of rare earth components, from each other.

### Claim 5 (depends on 4)

The method of claim 4, further comprising removing one or a specific mixed group of the rare earth components from the third continuous ion exchange system comprising a strong cationic exchange resin operating in the chromatographic mode by eluting the strong cation resin with an organic complexing solution, optionally an ammonium glycolate, resulting in a solution containing only one or substantially a specific mixed group of target rare earth components, to the exclusion of the other remaining rare earth components, and resulting in a solution substantially lacking or having minimal amounts of the minor element components, or the mixture of minor element components.

### Claim 6 (depends on 5)

The method of claim 5, wherein the solution containing specific rare earth components is a solution from which a rare earth salt can be precipitated.

### Claim 7 (depends on 5)

The method of claim 5, further comprising contacting the solution containing specific rare earth components with one or more other ion exchange systems, operating in a chromatographic mode to further separate rare earth components from each other or to produce more purified rare earth components, or mixtures of rare earth components.

### Claim 8 (depends on 1)

The method of claim 1, wherein the first continuous ion exchange system comprising a strong cationic exchange resin primarily binds the rare earth components, or mixtures of rare earth components, along with one or more minor element components or mixture of minor element components.

### Claim 9 (depends on 1)

The method of claim 1, wherein the first and the second continuous ion exchange systems comprising a strong cationic exchange resin comprise a gel polystyrene crosslinked with divinylbenzene and a sulfonic acid functional group.

### Claim 10 (depends on 1)

The method of claim 1, wherein the first continuous ion exchange system comprising a strong cationic exchange resin of step (b) capable of binding the rare earth components, or mixture of rare earth components, and one or more minor element components or mixture of minor element components, comprises beads, wires, meshes, nanobeads, nanotubes, nanowires, or hydrogels.

### Claim 11 (depends on 1)

The method of claim 1, wherein in step (c) the strong acid comprises: a sulfuric acid in the concentration range of about 15% to about 40%.

### Claim 12 (depends on 1)

The method of claim 1, wherein in step (c) the strong acid comprises: a nitric acid in a concentration range of about 15% to about 30%.

### Claim 13 (depends on 1)

The method of claim 1, wherein in step (c) the strong acid comprises: a hydrochloric acid in a concentration range of about 15% to about 30%.

### Claim 14 (depends on 1)

The method of claim 1, wherein in step (d) an effluent is produced that is substantially free of the rare earth components, or mixture of rare earth components, and one or more minor element components or the mixture of minor element components, and substantially most of the rare earth components, or mixture of rare earth components, and one or more minor element components or the mixture of minor element components, are bound to the first continuous ion exchange system comprising a strong cationic exchange resin.

### Claim 15 (depends on 1)

The method of claim 1, wherein in step (d) the concentration of the phos-acid feedstock of (a) is in the range of about 15% to about 30% phos-acid.

### Claim 16 (depends on 1)

The method of claim 1, wherein in step (d) the concentration of the phos-acid feedstock of (a) is in the range of about 40% up to about 54%.

### Claim 17 (depends on 2)

The method of claim 2, wherein the clarification process, filtering process or clarification aid comprises an activated clay, an activated carbon, an activated silica, or any combination thereof.

### Claim 18 (depends on 9)

The method of claim 9, wherein the resin further comprises:
a weakly acidic cationic exchange resin with chelating amino methyl phosphonic acid groups for the selective removal of transition heavy metals; or
a macroporous aminophosphonic acid chelating resin for the removal of metal cations.

### Claim 19 (depends on 9)

The method of claim 9, wherein the resin further comprises impregnated substrate materials where an organic sorbent is impregnated with an organic extractant.

### Claim 20 (depends on 9)

The method of claim 9, wherein the resin further comprises a composition or a material, or a non-resin solid or a semi-solid material, comprising chelating groups, functionalities or moieties capable of binding the rare earth components, or mixture of rare earth components from a sample.

### Claim 21 (depends on 18)

The method of claim 18, wherein the resin comprises beads, wires, meshes, nanobeads, nanotubes, nanowires, or hydrogels.

### Claim 22 (depends on 3)

The method of claim 3, wherein the eluate for the second continuous ion exchange system comprising a strong cationic ion exchange resin comprises acids, and optionally the acids comprise a sulfuric acid, a nitric acid, and a hydrochloric acid.

### Claim 23 (depends on 3)

The method of claim 3, wherein the eluate for the second continuous ion exchange system comprising a strong cationic ion exchange resin comprises an ammonium solution or an ammonium sulfate solution at a pH greater than about 8.

### Claim 24 (depends on 5)

The method of claim 5, wherein the eluate for the third continuous ion exchange system comprising a strong cationic ion exchange resin comprises an organic complexing agent.

### Claim 25 (depends on 4)

The method of claim 4, wherein the resin in the third continuous ion exchange system comprising a strong cationic exchange resin operating in the chromatographic mode comprises a gel polystyrene crosslinked with divinylbenzene and a sulfonic acid functional group.

### Claim 26 (depends on 4)

The method of claim 4, wherein the resin in the third continuous ion exchange system comprising a strong cationic exchange resin further comprises: a composition or a material, or a non-resin solid or a semi-solid material, comprising chelating groups, functionalities or moieties capable of binding the rare earth components, or mixture of rare earth components from a sample.

### Claim 27 (depends on 25)

The method of claim 25, wherein the resin in the third continuous ion exchange system comprising a strong cationic exchange resin comprises or is manufactured as beads, wires, meshes, nanobeads, nanotubes, nanowires, or hydrogels.

### Claim 28 (depends on 6)

The method of claim 6, wherein the solution from which a rare earth salt can be precipitated or the acid regeneration solution comprises a complexing material comprising an ammonium glycolate, optionally at a pH from about 3 to about 7, which allows for initial separation of the rare earth component, or mixture of rare earth components, and optionally is used for regeneration of the third continuous ion exchange system comprising a strong cationic exchange resin operating in the chromatographic mode if an initial group separation is not needed.

### Claim 29 (depends on 6)

The method of claim 6, wherein the solution from which a rare earth salt is precipitated or the acid regeneration solution comprises sulfuric acid or nitric acid.

### Claim 30 (depends on 5)

The method of claim 5, wherein the organic complexing solution comprises ammonium glycolate.

### Claim 31 (depends on 19)

The method of claim 19, wherein the organic extractant comprises tri-butyl phosphate or di-2-ethylhexyl phosphoric acid.

### Claim 32 (depends on 29)

The method of claim 29, wherein the solution from which a rare earth salt is precipitated or the acid regeneration solution comprises sulfuric acid or nitric acid is in about a 10% to about a 20% concentration range.

### Claim 33 (depends on 29)

The method of claim 29, wherein the solution from which a rare earth salt is precipitated or the acid regeneration solution is used for regeneration of the third continuous ion exchange system comprising a strong cationic exchange resin operating in the chromatographic mode if an initial group separation is not needed.

### Claim 34 (depends on 1)

The method of claim 1, wherein the acid regeneration solution is processed to precipitate a mixed rare earth salt, wherein optionally the mixed rare earth salt is a rare earth carbonate.

### Claim 35 (depends on 1)

The method of claim 1, wherein the rare earth components or mixture of rare earth components, or the rare earth material, comprises lanthanum; cerium; europium; neodymium; or yttrium.

### Claim 36 (depends on 1)

The method of claim 1, wherein in step (c) the strong acid comprises sulfuric acid, and use of the acid regeneration solution results in or thereby produces a solution of sulfuric acid.

### Claim 37 (depends on 24)

The method of claim 24, wherein the eluate for the third continuous ion exchange system comprising a strong cationic exchange resin comprises an organic complexing agent comprising an ammonium glycolate, wherein optionally the organic complexing agent is at a pH of about 3 to about 7.