Processes for recovering lithium values from lithium-containing brines

Patent metadata

Field	Value
Publication number	US-12570537-B2
Application number	US-202418781703-A
Country	US
Kind code	B2
Filing date	Jul 23, 2024
Priority date	Jan 19, 2024
Publication date	Mar 10, 2026
Grant date	Mar 10, 2026

Abstract

Producing high purity lithium solution from a source brine containing at least 1 mg Li/kg brine, preferably 10 mg/kg, more preferably 25 mg Li/kg brine; treating the source brine, if necessary in pretreatment steps; processing the treated brine in a lithium adsorption step; after the adsorption step, desorbing the adsorbed lithium in a desorption step; after the desorption step, treating the desorption effluent in an enrichment step. Specified optional steps and new features can be used to increase lithium concentrations and purity.

First claim

That which is claimed is:

1 . A process for producing a high purity aqueous lithium-containing solution from a source of dissolved lithium, which process comprises:
a. a source brine containing at least 1 mg Li/kg brine; b. treating the source brine in one or more pretreatment steps comprising;
i. concentration of Li in the source brine or evaporation of water in the source brine comprising one or more of fractional freezing, membrane techniques, thermal evaporation, vacuum evaporation, cooling tower evaporation including forced or induced draft, solar evaporation, forced air evaporation or passive evaporation; and
ii. adjustment of a temperature of the source brine to less than 110 degrees C.;
c. processing the treated brine in a lithium adsorption step; d. after the adsorption step, desorbing the adsorbed lithium in a desorption step; e. after the desorption step and prior to an enrichment step, treating the desorption effluent to remove impurities, wherein the treatment step creates a brine of less than about 100 ppm of residual H2S or other sulfides; and f. after the treatment step, treating the desorption effluent in the enrichment step comprising membrane filtration and ion exchange resin; and g. regenerating the ion exchange resin, wherein solutions used to regenerate the ion exchange resin are recycled to adjust pH or osmotic strength elsewhere in the enrichment step or the adsorption step or the desorption step or in lithium depleted brine.

2 . The process of claim 1 , wherein a concentration of the Li in the source brine solution is adjusted through introduction of water or aqueous recycle streams or nanofiltration/reverse osmosis permeates or concentrates.

3 . The process of claim 1 , further comprising providing solutions made of one or more of NaCl, MgCl2, KCl, CaCl2 to displace the brine in the treated brine after the adsorption step prior to the desorption step to minimize the lithium loss.

4 . A process for producing lithium salts comprising the process of claim 1 , followed by fractional crystallization of NaCl to produce LiCl or other saleable lithium salt solutions selected from lithium bromide, lithium phosphate, lithium sulfate, lithium hydroxide and solutions and hydrates of each.

5 . The process of claim 4 , further comprising wherein a LiCl solution is converted to solid LiCl or its hydrates or a mixture of the two.

6 . A process for producing Li 2 CO 3 comprising the process of claim 1 , followed by the introduction of Na2CO3 or K2CO3 or NaOH or KOH in the presence of CO2 to precipitate Li2CO3.

7 . A process of claim 1 , wherein the pretreatment steps further comprise a pretreatment step to remove impurities.

8 . The process of claim 7 , further comprising wherein the pretreatment step creates a brine with native hydrocarbons or other organics present as dissolved and free phase organics of less than about 0.3 wt %.

9 . The process of claim 7 , further comprising wherein the pretreatment step creates a brine of residual sulfur compounds including H2S or other sulfides less than about 100 ppm sulfur.

10 . The process of claim 7 , further comprising wherein the pretreatment step creates a brine of free halogen less than about 500 ppm.

11 . The process of claim 7 , further comprising wherein the pretreatment step creates a brine with total nondissolved solids less than about 1000 ppm.

12 . The process of claim 1 , further comprising wherein the treatment step creates a brine with native hydrocarbons or other organics present as dissolved and free phase organics of less than about 0.3 wt.

13 . The process of claim 1 , further comprising wherein the treatment step creates a brine of free halogen less than about 500 ppm.

14 . The process of claim 12 , further comprising wherein the treatment step creates a brine with total nondissolved solids less than about 1000 ppm.

15 . The process of claim 1 , comprising recycling lithium depleted brine effluent or any of the desorption effluent during the process.

16 . The process of claim 15 , wherein an aqueous solution generated during enrichment is recycled to the desorption influent.

17 . The process of claim 15 , wherein the aqueous solution generated during enrichment is recycled to one or more of stages of a multistage nanofiltration system.

18 . The process of claim 1 , wherein the enrichment step comprises one or more of the following: membrane technologies including nanofiltration, forward osmosis, reverse osmosis and osmotically assisted reverse osmosis, electrodialysis, chemical precipitation, ion exchange resins including cation exchange resins and anion exchange resins and evaporation or other water removal or concentration techniques.

19 . The process of claim 18 , wherein NaCl is recovered from desorption effluent or process stream during or after the enrichment step and subjected to nanofiltration, reverse osmosis, or selective precipitation and used to adjust osmotic strength of brine, desorption, or enrichment solutions, regenerate an ion exchange resin, or provide for minimized waste disposal costs as concentrated brine or for zero liquid discharge solid waste.

20 . The process of claim 18 , further comprising the enrichment step creating a brine effluent with lithium concentrations of 0.25% to 5.

21 . The process of claim 1 , further comprising wherein the treatment of the source brine creates a brine with a pH value in the range of 1-9.

22 . The process of claim 1 , wherein effluent desorption solution used in the desorption step contains at least 5 ppm Li.

23 . The process of claim 1 , wherein the lithium bearing source brine is subjected to two or more stages of adsorption in one or more contact vessels.

24 . The process of claim 1 , wherein in the adsorption step at least about 50% of the lithium is adsorbed.

25 . The process of claim 1 , wherein in the adsorption step at least about 90% of the lithium is adsorbed.

26 . The process of claim 1 , wherein the treatment includes fractional treatment of the solution within one or more nanofiltration or RO units or any combination of the two units in step (e) and subsequent permeate is recycled elsewhere in the process.

27 . The process of claim 1 , wherein the lithium desorption step is conducted by washing sorbent with water or a dilute aqueous solution of lithium chloride containing 50-300 ppm Li, at a temperature of 40-100° C.

Assignees

• Albemarle Corp

Inventors

• Dupont Jesse
• Leblanc Jeffrey Ross
• Shah Keyur
• Talreja Sameer

Classifications

• C01D15/08 Primary

  Carbonates; Bicarbonates · CPC title

• B01D61/0271

  comprising multiple nanofiltration steps · CPC title

• C01P2006/80

  Compositional purity · CPC title

• B01D9/004

  Fractional crystallisation; Fractionating or rectifying columns · CPC title

• B01D9/0004

  cooling by heat exchange (by evaporation of components of the mixture to be separated B01D9/0013; refrigeration machines F25B) · CPC title