Method for comprehensively recovering rare earth elements and fluorine element in a bastnaesite treatment process

Patent metadata

Field	Value
Publication number	US-9752213-B2
Application number	US-201314430268-A
Country	US
Kind code	B2
Filing date	Sep 29, 2013
Priority date	Sep 29, 2012
Publication date	Sep 5, 2017
Grant date	Sep 5, 2017

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.

First claim

The invention claimed is:

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.

2. 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.

3. 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.

4. 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.

5. 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.

6. 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.

7. 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.

8. 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.

9. 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.

10. 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.

11. 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.

12. 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.

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.

14. 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.

15. 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.

16. 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.

17. 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.

18. 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.

Assignees

• Grirem Advanced Mat Co Ltd

Inventors

• Wang Liangshi
• Long Zhiqi
• Cui Dali
• Huang Xiaowei
• Yu Ying
• Xu Yang
• Feng Xingliang

Classifications

• C22B59/00 Primary

  Obtaining rare earth metals · CPC title

• Y02P10/234

  Cross-Sectional Technologies · mapped topic

• C22B3/10

  Hydrochloric acid {, other halogenated acids or salts thereof} · CPC title

• C22B1/02

  Roasting processes (C22B1/16 takes precedence) · CPC title

• Y02P10/20

  Recycling · CPC title