# US 12,215,408 B2 · Processes for the separation of rare earth elements and non-rare earth elements into individual high purity elements

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- Number: US 12,215,408 B2
- Document ID: US12215408B2
- Status: Granted
- Kind: B2
- Application number: 17/118,386
- Filed: 2020-12-10
- Published: 2021-06-10
- Granted: 2025-02-04
- Earliest claimed: 2019-12-10
- Assignees: Inventure Renewables, Inc.
- Applicants: Inventure Renewables, Inc.
- Inventors: William Rusty Sutterlin
- Web page: https://patentgrep.com/patent/US12215408B2

## CPC

- C22B 3/10: Hydrochloric acid {, other halogenated acids or salts thereof}
- C22B 59/00: Obtaining rare earth metals
- C22B 3/42: by ion-exchange extraction
- C22B 7/007: {by acid leaching}
- Y02P 10/20: Recycling
- C22B: PRODUCTION AND REFINING OF METALS (electrolytic C25); PRETREATMENT OF RAW MATERIALS
- Y02P: CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS

## Abstract

In alternative embodiments, provided are processes and continuous ion exchange/continuous ion chromatography (CIX/CIC) systems for the separation of rare earth elements and non-rare earth elements, including metals, into individual high purity elements.

## Claims

### Claim 1

A continuous ion exchange/continuous ion chromatography (CIX/CIC) process for the separation of rare earth elements (REEs) and non-rare earth elements from a feedstock starting material comprising at least one rare earth element (REE) and at least one non-rare earth element and having iron as a contaminant, comprising sequential use of a CIX/CIC anion exchange resin column to first remove ferric tetrachloride anion FeCl4− followed by a CIX/CIC cationic exchange resin column to isolate REEs,
the method comprising the steps of:
(a) providing the feedstock starting material comprising at least one rare earth element (REE) and at least one non-rare earth element and having iron as a contaminant;
(b) making a modified feedstock by a process comprising mixing the feedstock starting material in a hydrochloric acid (HCl) solution, or adding the feedstock starting material to the hydrochloric acid solution, wherein the hydrochloric acid solution has a concentration of between about 0.01 molarity and 10 molarity, wherein the iron reacts with the HCl in the presence of chlorides to generate a plurality of FeCl4− anion complexes,
thereby generating a modified feedstock starting material comprising the hydrochloric acid
(c) adding or loading the modified feedstock starting material of step (b) into or onto a CIX/CIC anion exchange resin column, whereby the ferric tetrachloride anion FeCl4− in the modified feedstock starting material is retained on the CIX/CIC anion exchange resin, and generating a first eluate;
(d) adding or loading the first eluate of (c) into or onto a CIX/CIC cationic exchange resin column, whereby REEs are retained on the CIX/CIC cationic exchange resin; and
(e) passing low to high gradient acid eluting solutions over or through the CIX/CIC cationic exchange resin column to generate a second eluate comprising REE,
wherein the passing comprises:
(i) first passing a first HCl acid-comprising eluting solution having a low HCl acid concentration of about 0.1 to 1 molarity thereby generating a second eluate wherein greater than about 50% of monovalent and/or divalent cations are eluted off the CIX/CIC cationic exchange resin column in the second eluate, followed by a second HCl acid-comprising eluting solution of about 1 to 2 HCl acid molarity thereby generating a third eluate wherein greater than about 50% of trivalent cations are eluted off the CIX/CIC cationic exchange resin column in the third eluate, followed by a third HCl acid-comprising eluting solution of about 3 to 10 or more HCl acid molarity thereby generating a fourth eluate wherein greater than about 50% of the REEs elute off the CIX/CIC cationic exchange resin column in the fourth eluate, or
(ii) passing an HCl acid-comprising eluting solution over or through the cationic exchange resin column, wherein the HCl acid-comprising eluting solution changes over time from: a first HCl acid-comprising eluting solution comprising about 0.1 to 1 HCl acid molarity thereby generating a second eluate wherein greater than about 50% of monovalent and/or divalent cations are eluted off the CIX/CIC cationic exchange resin column in the second eluate, to a second HCl acid-comprising eluting solution comprising about 1 to 2 molarity thereby generating a third eluate wherein greater than about 50% of trivalent cations are eluted off the CIX/CIC cationic exchange resin column in the third eluate, to a third HCl acid-comprising eluting solution comprising about 3 to 10 or more HCl acid molarity thereby generating a fourth eluate wherein greater than about 50% of the REEs elute off the CIX/CIC cationic exchange resin column in the fourth eluate;
thereby separating rare earth elements (REEs) and non-rare earth elements from the feedstock.

### Claim 2 (depends on 1)

The process of claim 1, wherein the at least one of the eluted REEs comprises lanthanum (La); cerium (Ce); praseodymium (Pr); neodymium (Nd); samarium (Sm); europium (Eu); gadolinium (Gd); terbium (Tb); dysprosium (Dy); holmium (Ho); erbium (Er); thulium (Tm); ytterbium (Yb); lutetium (Lu); yttrium (Y), scandium (Sc) or any combination thereof.

### Claim 3 (depends on 1)

The process of claim 1, wherein the non-rare earth elements comprise metals or metal oxides.

### Claim 4 (depends on 3)

The process of claim 3, wherein the metals or metal oxides comprise iron or iron oxides, or aluminum or aluminum oxides.

### Claim 5 (depends on 4)

The process of claim 4, wherein the metals or metal oxides comprise iron or iron oxides, or aluminum or aluminum oxides.

### Claim 6 (depends on 1)

The process of claim 1, wherein the feedstock starting material comprises a mining waste, an acid mine drainage (AMD), an acid rock drainage (ARD), an acid or metalliferous drainage, AMD sludge, a coal overburden, a fire clay, a fly ash, an ore or any combination thereof.

### Claim 7 (depends on 1)

The process of claim 1, wherein the CIX/CIC anion exchange resin comprises a polymeric matrix to which functional groups are attached.

### Claim 8 (depends on 7)

The process of claim 7, wherein the functional groups comprise: tertiary amino groups; primary amines; secondary amines; quaternary ammonium groups or a combination thereof.

### Claim 9 (depends on 7)

The process of claim 7, wherein the polymeric matrix comprises:
N+(CH3)3 groups (type 1 resins);
—N+(CH3)2C2H4OH groups (type 2 resins); or,
a combination thereof.

### Claim 10 (depends on 7)

The process of claim 7, wherein the polymeric matrix comprises styrene-divinylbenzene.

### Claim 11 (depends on 1)

The process of claim 1, further comprising regenerating the CIX/CIC anion exchange resin after step (c) to generate a fifth eluate, wherein the CIX/CIC anion exchange resin having
ferric tetrachloride anion FeCl4− retained thereon is regenerated by adding or loading a water elution solution through the CIX/CIC anion exchange resin and eluting off ferric tetrachloride anion FeCl4−, and any zinc, thorium and/or uranium if present, to generate the fifth eluate comprising FeCl3,
wherein the water dilutes the FeCl4− and any zinc, thorium and/or uranium if present, and generates FeCl3 which is not anionic and therefore not attracted to the anion exchange resin.

### Claim 12 (depends on 11)

The process of claim 11, further comprising collecting and recycling the fifth eluate comprising FeCl3.

### Claim 13 (depends on 1)

The process of claim 1, wherein the CIX/CIC cationic exchange resin comprises crosslinked polystyrene, divinylbenzene or a combination thereof, or comprises sulfonic acid groups, carboxylic acid groups or a combination thereof.

### Claim 14 (depends on 1)

The process of claim 1, wherein in step (c) any zinc, thorium and/or uranium in the modified feedstock starting material is retained on the CIX/CIC anion exchange resin column.

### Claim 15 (depends on 1)

The process of claim 1, wherein the trivalent cations comprise aluminum cations.

### Claim 16 (depends on 1)

The process of claim 1, wherein in step (e) (ii) at low acid concentration of about 1 molarity or less at least about 60% of monovalent and/or divalent cations are eluted off the CIX/CIC cationic exchange resin column.

### Claim 17 (depends on 16)

The process of claim 16, wherein in step (e) (ii) at low acid concentration of about 1 molarity or less at least about 95% of monovalent and/or divalent cations are eluted off the CIX/CIC cationic exchange resin column.

### Claim 18 (depends on 1)

The process of claim 1, wherein in step (e) (ii) at acid concentrations of between about 1 to 2 molarity greater than about 60% of trivalent cations elute off the CIX/CIC cationic exchange resin column.

### Claim 19 (depends on 18)

The process of claim 18, wherein in step (e) (ii) at acid concentrations of between about 1 to 2 molarity greater than about 95% of trivalent cations elute off the CIX/CIC cationic exchange resin column.

### Claim 20 (depends on 1)

The process of claim 1, wherein in step (e) (ii) at acid concentrations greater than about 3 or more molarity, greater than about 60% of the REEs elute off the CIX/CIC cationic exchange resin column.

### Claim 21 (depends on 20)

The process of claim 20, wherein in step (e) (ii) at acid concentrations greater than about 3 or more molarity, greater than about 70% of the REEs elute off the CIX/CIC cationic exchange resin column.

### Claim 22 (depends on 21)

The process of claim 21, wherein in step (e) (ii) at acid concentrations greater than about 3 or more molarity, greater than about 95% of the REEs elute off the CIX/CIC cationic exchange resin column.

### Claim 23 (depends on 1)

The process of claim 1, wherein the feedstock starting material comprises a coal byproduct or a coal overburden product.

### Claim 24 (depends on 1)

The process of claim 1, wherein the first eluate has greater than about 99.8% of the contaminant iron removed.