Selective lithium recovery as lithium carbonate from natural brines

Patent metadata

Field	Value
Publication number	US-10315926-B2
Application number	US-201715728784-A
Country	US
Kind code	B2
Filing date	Oct 10, 2017
Priority date	Feb 9, 2017
Publication date	Jun 11, 2019
Grant date	Jun 11, 2019

Abstract

Embodiments relate to methods, systems And apparatus tor generating lithium from brine. The brine is heated in a first vessel to greater than 260° C. and CO 2 gas is injected mixing with the brine such that the CO 2 /P is greater than 18 g/atm. The brine is held at greater than 18 g/atm for longer than 20 minutes so that any impurities precipitate as solids leaving only lithium ions and chlorine ions. The brine is moved to a second vessel screening out solid precipitates leaving a brine containing only chlorine and lithium. CO 2 gas is injected and mixed with the brine at 260° C. so that the CO 2 /P is greater than 200 g/atm. The brine is held at greater than 200 g/atm for longer than 20 minutes suppressing the chlorine as dissolved ions while lithium precipitates out as lithium carbonate. The lithium carbonate precipitate is removed from the brine solution.

First claim

We claim:

1. A method for generating lithium from a natural brine, comprising:
heating a natural brine in a first vessel to a first predetermined temperature;
injecting a CO 2 gas into the first vessel, the CO 2 gas mixes with the natural brine forming a mixture such that the CO 2 /P is greater than 6 g/atm;
holding the mixture for a first predetermined time after the CO 2 injection such that impurities in the natural brine precipitate as solids leaving a second brine substantially comprising dissolved lithium ions and dissolved chlorine ions;
screening out the solid precipitate impurities from the second brine;
heating the second brine to a second predetermined temperature;
injecting CO 2 gas into the second brine, the CO 2 gas mixes with the second brine forming a second mixture such that the CO 2 /P is greater than 50 g/atm;
holding the second mixture for a second predetermined time after the CO 2 injection such that chlorine is suppressed as dissolved ions while lithium ions precipitate out as lithium carbonate as substantially the only solid in the second mixture; and
removing the lithium carbonate precipitate.

2. The method for generating lithium from a natural brine of claim 1 wherein said first predetermined temperature is at least 200° C.

3. The method for generating lithium from a natural brine of claim 1 wherein said first predetermined temperature is equal to or greater than 260° C.

4. The method for generating lithium from a natural brine of claim 1 wherein said CO 2 /P of the first mixture is greater than 18 g/atm.

5. The method for generating lithium from a natural brine of claim 1 wherein said first predetermined time is longer than 3 minutes.

6. The method for generating lithium from a natural brine of claim 1 wherein said first predetermined time is longer than 20 minutes.

7. The method for generating lithium from a natural brine of claim 1 whereby said step of screening comprises moving the mixture into a second vessel.

8. The method for generating lithium from a natural brine of claim 1 whereby said step of screening comprises filtering the mixture through a sieve.

9. The method for generating lithium from a natural brine of claim 1 wherein said second predetermined temperature is equal to the first predetermined temperature.

10. The method for generating lithium from a natural brine of claim 1 wherein said second predetermined temperature is at least 200° C.

11. The method for generating lithium from a natural brine of claim 1 wherein said second predetermined temperature is equal to or greater than 260° C.

12. The method for generating lithium from a natural brine of claim 1 wherein said CO 2 /P of the second mixture is greater than 200 g/atm.

13. The method for generating lithium from a natural brine of claim 1 wherein said second predetermined time is at least 3minutes.

14. The method for generating lithium from a natural brine of claim 1 wherein said second predetermined time is at least 20 minutes.

15. The method for generating lithium from a natural brine of claim 1 whereby substantially all of the lithium from the natural brine is recovered as Li 2 CO 3 with a greater than 99.0% purity of the recovered lithium.

Assignees

• Us Energy
• Us Dept Energy

Inventors

• Nakano Jinichiro
• Nakano Anna
• Bennett James P

Classifications

• C01P2006/80

  Compositional purity · CPC title

• C22C24/00

  Alloys based on an alkali or an alkaline earth metal · CPC title

• C01D15/08 Primary

  Carbonates; Bicarbonates · CPC title