Integrated lithium production process

1. A method of producing an aqueous lithium-containing solution from a lithium-loaded organic medium, the method comprising:

(a) providing a two-compartment electrolysis cell having an anode, a cathode, and a membrane barrier disposed therebetween, said membrane barrier being permeable to lithium (Li + ) cations and to protons (H + );

(b) stripping the lithium-loaded organic medium by means of an aqueous stripping solution, to extract said lithium cations from the lithium-loaded organic medium into the aqueous stripping solution, producing an aqueous, lithium-containing intermediate solution along with a stripped organic medium;

(c) introducing said aqueous, lithium-containing intermediate solution into an anodic compartment of said two-compartment electrolysis cell, to form an anolyte;

(d) introducing an aqueous medium into a cathodic compartment of said two-compartment electrolysis cell to form a catholyte;

(e) operating said cell so as to:

(i) generate oxygen gas at said anode;

(ii) produce said protons (H + ) within said anolyte; and

(iii) generate hydrogen gas and hydroxide (OH − ) at said cathode;

and such that a portion of said lithium cations and a portion of said protons traverse said membrane barrier, whereby said protons react with said hydroxide to produce water in said catholyte;

(f) removing an aqueous product stream from said cathodic compartment, said product stream containing dissolved lithium hydroxide values; and

(g) recycling a discharge stream from said anodic compartment, for use in said stripping of the lithium-loaded organic medium;

the method further comprising:

(h) between steps (b) and (c), separating said lithium-containing aqueous intermediate solution from said stripped organic medium;

(i) returning said stripped organic medium to an extraction stage; and

(j) mixing an aqueous lithium-containing feed solution with said stripped organic medium, in said extraction stage, to produce said lithium-loaded organic medium;

wherein, within said lithium-containing intermediate solution, said lithium cations are a predominant cation;

wherein said discharge stream contains said lithium cations (Li + ) and said protons (H + ) in a molar ratio within a range of 40:1 to 1:2;

wherein a lithium conversion of said lithium cations is defined as a ration of an amount of said lithium cations in said aqueous product stream to a total amount of said lithium cations introduced to said two-compartment electrolysis cell,

wherein said lithium conversion is at most 25%,

and wherein, for a continuous process, said ratio of an amount of said lithium cations in said aqueous product stream to said total amount of said lithium cations introduced to said two-compartment electrolysis cell is evaluated during continuous, steady-state operation.

2. The method of claim 1 , wherein said molar ratio is within a range of 10:1 to 1:2.

3. The method of claim 1 , wherein said membrane barrier is a perfluorinated cation exchange membrane.

4. The method of claim 1 , wherein said lithium conversion is at most 20%.

5. The method of claim 1 , wherein, within said lithium-containing intermediate solution, sulfate anion is a predominant anion.

6. The method of claim 1 , wherein the method is devoid of a three-compartment electrolysis process.

7. The method of claim 5 , wherein said lithium-loaded organic medium includes at least one organic species of the form R − —Li + , wherein R − is an organic proton acceptor or wherein R is an organic proton donor.

8. The method of claim 7 , wherein R includes at least one C 1 -C 10 alcohol.

9. The method of claim 7 , wherein R includes a ketone.

10. The method of claim 2 , wherein a concentration of said dissolved lithium hydroxide values in said product stream is within a range of 0.5 to 4.5 M, and wherein said lithium-loaded organic medium includes at least one organic species of the form R − —Li + wherein R − is an organic proton acceptor or wherein R is an organic proton donor.

11. A method of producing an aqueous lithium-containing solution from a lithium-loaded organic medium, the method comprising:

(a) providing a two-compartment electrolysis cell having an anode, a cathode, and a membrane barrier disposed therebetween, said membrane barrier being permeable to lithium (Li + ) cations and to protons (H + );

(b) stripping the lithium-loaded organic medium by means of an aqueous stripping solution, to extract said lithium cations from the lithium-loaded organic medium into the aqueous stripping solution, producing an aqueous, lithium-containing intermediate solution along with a stripped organic medium;

(c) introducing said aqueous, lithium-containing intermediate solution into an anodic compartment of said two-compartment electrolysis cell, to form an anolyte;

(d) introducing an aqueous medium into a cathodic compartment of said two-compartment electrolysis cell to form a catholyte;

(e) operating said cell so as to:

(i) generate oxygen gas at said anode;

(ii) produce said protons (H + ) within said anolyte; and

(iii) generate hydrogen gas and hydroxide (OH − ) at said cathode;

and such that a portion of said lithium cations and a portion of said protons traverse said membrane barrier, whereby said protons react with said hydroxide to produce water in said catholyte;

(f) removing an aqueous product stream from said cathodic compartment, said product stream containing dissolved lithium hydroxide values; and

(g) recycling a discharge stream from said anodic compartment, for use in said stripping of the lithium-loaded organic medium;

the method further comprising:

(h) between steps (b) and (c), separating said lithium-containing aqueous intermediate solution from said stripped organic medium;

(i) returning said stripped organic medium to an extraction stage; and

(j) mixing an aqueous lithium-containing feed solution with said stripped organic medium, in said extraction stage, to produce said lithium-loaded organic medium;

wherein, within said lithium-containing intermediate solution, said lithium cations are a predominant cation;

wherein said discharge stream contains said lithium cations (Li + ) and said protons (H + ) in a molar ratio within a range of 40:1 to 1:2;

wherein a ratio of an amount of said lithium cations in said discharge stream to an amount of said lithium cations in said lithium-containing intermediate solution, is defined as R anolyte , a lithium conversion (C Li ) of said lithium cations is defined as:

C Li =1− R anolyte

wherein said lithium conversion, expressed as a percentage, is at most 25%;

and wherein, for a continuous process, said ratio of an amount of said lithium cations in said aqueous product stream to said total amount of said lithium cations introduced to said two-compartment electrolysis cell is evaluated during continuous, steady-state operation.

12. The method of claim 11 , wherein said molar ratio is within a range of 10:1 to 1:2.

13. The method of claim 11 , wherein, within said lithium-containing intermediate solution, sulfate anion is a predominant anion.

14. The method of claim 11 , wherein said lithium conversion is at most 20%.

15. The method of claim 13 , wherein said lithium conversion is at most 20%.

16. The method of claim 11 , wherein said membrane barrier is a perfluorinated cation exchange membrane.

17. The method of claim 11 , wherein said lithium-loaded organic medium includes at least one organic species of the form R − —Li + , wherein R − is an organic proton acceptor or wherein R is an organic proton donor.

18. The method of claim 17 , wherein R includes at least one C 1 -C 10 alcohol.

19. The method of claim 17 , wherein R includes a ketone.

20. The method of claim 13 , wherein said molar ratio is within a range of 10:1 to 1:2, wherein a concentration of said dissolved lithium hydroxide values in said product stream is within a range of 0.5 to 4.5 M, and wherein said lithium-loaded organic medium includes at least one organic species of the form R − —Li + wherein R − is an organic proton acceptor or wherein R is an organic proton donor.