# US 9,752,213 B2 · Method for comprehensively recovering rare earth elements and fluorine element in a bastnaesite treatment process

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- Number: US 9,752,213 B2
- Document ID: US9752213B2
- Status: Granted
- Kind: B2
- Application number: 14/430,268
- Filed: 2013-09-29
- Published: 2015-09-10
- Granted: 2017-09-05
- Earliest claimed: 2012-09-29
- Assignees: Grirem Advanced Materials Co., Ltd.
- Applicants: Grirem Advanced Materials Co., Ltd.
- Inventors: Liangshi Wang; Zhiqi Long; Dali Cui; Xiaowei Huang; Ying Yu; Yang Xu; Xingliang Feng
- Web page: https://patentgrep.com/patent/US9752213B2

## CPC

- C22B 59/00: Obtaining rare earth metals
- C22B 1/02: Roasting processes (C22B1/16 takes precedence)
- C22B 3/10: Hydrochloric acid {, other halogenated acids or salts thereof}
- 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

A method for comprehensively recovering rare earth elements and fluorine element in a bastnaesite treatment process. The method comprises: oxidation roasting a bastnaesite, and leaching a roasted mixture using a hydrochloric acid, adding a roasting promoter to the bastnaesite during the roasting process; and/or during the leaching process using the hydrochloric acid, adding a catalytic leaching promoter into the mixture, obtaining a rare earth chloride solution containing little cerium element and a cerium-rich residue containing the fluorine element; and separating and recovering rare earth fluorides from the cerium-rich residue.

## Claims

### Claim 1

A method for recovering rare earth elements and fluorine element in a bastnaesite treatment process, wherein the method comprises:
oxidation roasting bastnaesite to obtain a roasted mixture, and leaching the roasted mixture with hydrochloric acid,
adding a roasting promoter to the bastnaesite during the oxidation roasting; and
adding a catalytic leaching promoter to the mixture during the leaching with hydrochloric acid;
obtaining a rare earth chloride solution containing little cerium element and a cerium-rich residue containing the fluorine element; and
separating and recovering rare earth fluorides from the cerium-rich residue;
wherein the catalytic leaching promoter is at least one selected from the group consisting of magnesium sulfate, ammonium sulfate, a rare earth sulfate, ammonium ceric nitrate, cerium(IV) nitrate, aluminum nitrate, aluminum chloride, aluminum sulfate, sodium fluoride, potassium fluoride, ammonium fluoride and aluminum fluoride;
or
the method for recovering rare earth elements and fluorine element in a bastnaesite treatment process, comprising:
oxidation roasting bastnaesite to obtain a roasted mixture, and leaching the roasted mixture with hydrochloric acid,
adding a catalytic leaching promoter to the mixture during the leaching with hydrochloric acid;
obtaining a rare earth chloride solution containing little cerium element and a cerium-rich residue containing the fluorine element; and
separating and recovering rare earth fluorides from the cerium-rich residue;
wherein the catalytic leaching promoter is at least one selected from the group consisting of magnesium sulfate, ammonium sulfate, a rare earth sulfate, ammonium ceric nitrate, cerium(IV) nitrate, aluminum nitrate, aluminum chloride, aluminum sulfate, sodium fluoride, potassium fluoride, ammonium fluoride and aluminum fluoride.

### Claim 2 (depends on 1)

The method for recovering rare earth elements and fluorine element in a bastnaesite treatment process according to claim 1, wherein the roasting promoter is at least one selected from the group consisting of sodium sulfate, potassium sulfate, magnesium sulfate, ammonium sulfate, aluminum sulfate, a rare earth sulfate, ammonium eerie nitrate, cerium (IV) nitrate, aluminum nitrate, aluminum chloride, sodium fluoride, potassium fluoride, ammonium fluoride and aluminum fluoride.

### Claim 3 (depends on 2)

The method for recovering rare earth elements and fluorine element in a bastnaesite treatment process according to claim 2, wherein the rare earth sulfates includes cerium sulfate.

### Claim 4 (depends on 1)

The method for comprehensively recovering rare earth elements and fluorine element in a bastnaesite treatment process according to claim 1, wherein an amount of the roasting promoter is 0.01˜5% by weight of the bastnaesite.

### Claim 5 (depends on 1)

The method for recovering rare earth elements and fluorine element in a bastnaesite treatment process according to claim 1, wherein an amount of the catalytic leaching promoter is 0.01˜5% by weight of the bastnaesite.

### Claim 6 (depends on 1)

The method for recovering rare earth elements and fluorine element in a bastnaesite treatment process according to claim 1, wherein the bastnaesite is oxidation roasted for 0.5˜5 hr at a controlled temperature of 350˜600° C.

### Claim 7 (depends on 1)

The method for recovering rare earth elements and fluorine element in a bastnaesite treatment process according to claim 1, wherein the leaching with hydrochloric acid is carried out at 20˜80° C.

### Claim 8 (depends on 4)

The method for recovering rare earth elements and fluorine element in a bastnaesite treatment process according to claim 4, wherein an amount of the roasting promoter is 0.1˜3% by weight of the bastnaesite.

### Claim 9 (depends on 5)

The method for recovering rare earth elements and fluorine element in a bastnaesite treatment process according to claim 5, wherein an amount of the catalytic leaching promoter is 0.1˜3% by weight of the bastnaesite.

### Claim 10 (depends on 6)

The method for recovering rare earth elements and fluorine element in a bastnaesite treatment process according to claim 6, wherein the bastnaesite is oxidation roasted for 1˜5 hr at a controlled temperature of 400˜500° C.

### Claim 11 (depends on 7)

The method for recovering rare earth elements and fluorine element in a bastnaesite treatment process according to claim 7, wherein the leaching process using the hydrochloric acid is carried out at 35˜50° C.

### Claim 12 (depends on 1)

The method for recovering rare earth elements and fluorine element in a bastnaesite treatment process according to claim 1, wherein the rare earth sulfate is cerium sulfate.

### Claim 13

A method for recovering rare earth elements and fluorine element in a bastnaesite treatment process, wherein the method comprises:
leaching bastnaesite with hydrochloric acid;
adding a catalytic leaching promoter during the leaching with hydrochloric acid;
obtaining a rare earth chloride solution containing little cerium element and a cerium-rich residue containing the fluorine element; and
recovering rare earth fluorides from the cerium-rich residue;
wherein the catalytic leaching promoter is at least one selected from the group consisting of magnesium sulfate, ammonium sulfate, a rare earth sulfate, ammonium eerie nitrate, cerium (IV) nitrate, aluminum nitrate, aluminum chloride, aluminum sulfate, sodium fluoride, potassium fluoride, ammonium fluoride and aluminum fluoride.

### Claim 14 (depends on 13)

The method for recovering rare earth elements and fluorine element in a bastnaesite treatment process according to claim 13, wherein an amount of the catalytic leaching promoter is 0.01˜5% by weight of the bastnaesite.

### Claim 15 (depends on 13)

The method for recovering rare earth elements and fluorine element in a bastnaesite treatment process according to claim 13, wherein the leaching process using the hydrochloric acid is carried out at 80˜250° C.

### Claim 16 (depends on 14)

The method for recovering rare earth elements and fluorine element in a bastnaesite treatment process according to claim 14, wherein an amount of the catalytic leaching promoter is 0.1˜3% by weight of the bastnaesite.

### Claim 17 (depends on 15)

The method for recovering rare earth elements and fluorine element in a bastnaesite treatment process according to claim 15, wherein the leaching process using the hydrochloric acid is carried out at 100˜200° C.

### Claim 18 (depends on 13)

The method for recovering rare earth elements and fluorine element in a bastnaesite treatment process according to claim 13, wherein the rare earth sulfate is cerium sulfate.