Processes for preparing highly pure lithium carbonate and other highly pure lithium containing compounds

• US 9,074,265 B2
• Filed: 10/03/2013
• Issued: 07/07/2015
• Est. Priority Date: 02/17/2010
• Status: Active Grant

• Current Assignee: TerraLithium LLC (Occidental Petroleum Corporation)
• Original Assignee: Simbol, Inc.
• Inventors: Harrison, Stephen, Blanchet, Robert
• Primary Examiner(s): Rump, Richard M
• Application Number:
  US14/045,297
• Publication Number:
  US 20140037521A1
• Time in Patent Office: 642 Days
• Field of Search: 423/165, 423/419.1, 423/430, 423/551, 429/322, 429/321.95
• US Class Current: 1/1
• CPC Class Codes: C01B 35/063 Tetrafluoboric acid; Salts thereof
• CPC Class Codes: C01D 15/02 Oxides; Hydroxides
• CPC Class Codes: C01D 15/04 Halides
• CPC Class Codes: C01D 15/08 Carbonates; Bicarbonates
• CPC Class Codes: C01G 45/1228 of the type [MnO2]n- , e.g. LiMnO2, Li[MxMn1-x]O2
• CPC Class Codes: C01G 51/42 containing alkali metals, e.g. LiCoO2
• CPC Class Codes: C01P 2006/80 Compositional purity
• CPC Class Codes: C22B 26/12 Obtaining lithium
• CPC Class Codes: C25B 1/02 Hydrogen or oxygen
• CPC Class Codes: C25B 1/16 Hydroxides by simultaneous production of alkali metal hydroxides and chlorine, oxyacids or salts of chlorine C25B1/34
• CPC Class Codes: C25B 1/26 Chlorine; Compounds thereof by simultaneous production of alkali metal hydroxides and chlorine, oxyacids or salts of chlorine C25B1/34
• CPC Class Codes: C25B 1/46 in diaphragm cells
• CPC Class Codes: C25B 15/08 Supplying or removing reactants or electrolytes; Regeneration of electrolytes

Abstract

The invention generally relates to methods of selectively removing lithium from various liquids, methods of producing high purity lithium carbonate, methods of producing high purity lithium hydroxide, and methods of regenerating resin.

Claims

1. A method of producing high purity lithium carbonate, the method comprising the steps of:

supplying a first aqueous solution containing lithium sulfate to an electrochemical cell;

electrolyzing the first aqueous solution to produce a second aqueous solution containing sulfuric acid and a third aqueous solution containing high purity lithium hydroxide;

reacting the third aqueous solution containing high purity lithium hydroxide with carbon dioxide to produce a fourth aqueous solution containing lithium bicarbonate;

separating the fourth aqueous solution from the carbon dioxide and lithium carbonate solids using a gas-liquid-solid separator;

filtering the fourth aqueous solution to remove trace impurities; and

feeding the filtered fourth aqueous solution to a precipitation reactor to precipitate highly pure lithium carbonate.

2. The method of claim 1, wherein the step of reacting the third aqueous solution containing high purity lithium hydroxide with carbon dioxide produces the fourth aqueous solution having a pH of 8.5.

3. The method of claim 1, wherein the step of reacting the third aqueous solution containing high purity lithium hydroxide with carbon dioxide is carried out at a temperature of about 15°

C. to about 30°

C.

4. The method of claim 1, wherein the step of reacting the third aqueous solution containing high purity lithium hydroxide with carbon dioxide is carried out at a temperature of at least about 20°

C.

5. The method of claim 1, wherein the third aqueous solution containing high purity lithium hydroxide comprises at least 2 wt % lithium hydroxide.

6. The method of claim 1, wherein the third aqueous solution containing high purity lithium hydroxide comprises at least 4 wt % lithium hydroxide.

7. The method of claim 1, wherein the filtered fourth aqueous solution is passed through an ion exchange column to remove divalent ions before feeding the filtered fourth aqueous solution to a precipitation reactor.

8. The method of claim 7, wherein the divalent ions removed from the filtered fourth aqueous solution includes one or more of iron, silica, magnesium, manganese, calcium and strontium.

9. The method of claim 1, wherein the highly pure lithium carbonate produced in the precipitation reactor contains lithium in excess of 99.9% purity.

10. The method of claim 1, wherein the highly pure lithium carbonate produced in the precipitation reactor contains lithium in excess of 99.99% purity.

11. The method of claim 1, wherein the highly pure lithium carbonate produced in the precipitation reactor contains lithium in excess of 99.999% purity.

12. The method of claim 1, wherein the precipitation reactor is maintained at a temperature of at least about 95°

C. to precipitate highly pure lithium carbonate.

13. The method of claim 1, wherein the electrochemical cell includes a cathode, an anode, and a semi-permeable ion selective membrane.

14. The method of claim 1, wherein the anode contains titanium.

15. The method of claim 1, wherein the cathode contains nickel.

16. The method of claim 1, wherein the highly pure lithium carbonate produced in the precipitation reactor contains lithium carbonate particles having an average diameter of less than about 100 μ

m.

17. The method of claim 1, wherein the highly pure lithium carbonate produced in the precipitation reactor contains lithium carbonate particles having an average diameter of less than about 50 μ

m.

18. The method of claim 1, wherein the highly pure lithium carbonate produced in the precipitation reactor contains lithium carbonate particles having an average diameter of less than about 10 μ

m.

19. The method of claim 1, wherein the trace impurities removed from the fourth aqueous solution includes at least one or more of phosphates and borates.

20. A method of producing high purity lithium carbonate, the method comprising the steps of:

supplying a first aqueous solution containing lithium sulfate to an electrochemical cell;

electrolyzing the first aqueous solution to produce a second aqueous solution containing sulfuric acid and a third aqueous solution containing high purity lithium hydroxide;

reacting the third aqueous solution containing high purity lithium hydroxide with carbon dioxide to produce a fourth aqueous solution containing lithium bicarbonate;

separating the fourth aqueous solution from the carbon dioxide and lithium carbonate solids;

filtering the fourth aqueous solution to remove trace impurities;

feeding the filtered fourth aqueous solution to a precipitation reactor to precipitate highly pure lithium carbonate and a fifth aqueous solution containing lithium bicarbonate; and

supplying the fifth aqueous solution to a reverse osmosis apparatus to produce highly pure lithium carbonate, wherein the reverse osmosis apparatus is operable to remove CO₂ from the fifth aqueous solution and cause lithium carbonate to precipitate.