Process and method for refining lithium carbonate starting from an impure lithium chloride solution

Patent metadata

Field	Value
Publication number	US-12054807-B2
Application number	US-202017115140-A
Country	US
Kind code	B2
Filing date	Dec 8, 2020
Priority date	Dec 11, 2019
Publication date	Aug 6, 2024
Grant date	Aug 6, 2024

Abstract

A method for refining lithium from a crude brine includes charging a crude brine into a feeder tank held at a temperature T1 and containing a sufficient carbonate source to precipitate all carbonate-forming solids in the crude brine to form a precipitate mixture and a crystal free supernatant; pumping the crystal free supernatant from the feeder tank to a first crystallization reactor that is held at a temperature T2 to crystallize a lithium carbonate salt out of the crystal free supernatant; wherein the temperature T1 is lower than the temperature T2; and controlling a flow rate to maintain a steady state concentration of the lithium carbonate salt in the solution phase of the crystallization reactor.

First claim

The invention claimed is:

1. A method for refining lithium from a crude brine, comprising:
charging a crude brine into a feeder tank held at a temperature T 1 and containing a sufficient carbonate source to precipitate carbonate-forming solids in the crude brine to form a precipitate mixture and a crystal free supernatant; and
pumping the crystal free supernatant from the feeder tank to a first crystallization reactor that is held at a temperature T 2 to crystallize a lithium carbonate salt out of the crystal free supernatant;
wherein the temperature T 1 is lower than the temperature T 2 ;
controlling a flow rate of the crystal free supernatant from the feeder tank to the first crystallization reactor to maintain a steady state concentration of lithium carbonate in a solution phase of the crystallization reactor; and
pumping a solution phase in the first crystallization reactor into a second crystallization reactor that is held at a temperature T 3 ;
wherein the temperature T 3 is higher than the temperature T 2 .

2. The method of claim 1 , further comprising:
pumping a solution phase in the first crystallization reactor back into the feeder tank.

3. The method of claim 1 , wherein the first crystallization reactor is seeded with lithium carbonate crystal seeds.

4. The method of claim 1 , wherein the carbonate source is sodium carbonate, potassium carbonate, or carbon dioxide.

5. The method of claim 1 , further comprising:
continuing the method of pumping a solution phase from an “n” crystallization reactor to an “n+1” crystallization reactor wherein the “n+1” crystallization reactor is held at a temperature higher than the temperature of the “n” crystallization reactor;
wherein “n” is an integer greater than or equal to 2.

6. The method of claim 1 , wherein the flow rate of the crystal free supernatant from the feeder tank to the first crystallization reactor is sufficient to maintain a steady state concentration of dissolved lithium carbonate in the solution phase, such that the rate of crystallization is faster than the maximum flow rate employed.

7. The method of claim 1 , wherein the flow rate is adjusted to accommodate an addition rate of crystal free supernatant to crystallize between 50-250g Li 2 CO 3 per hour.

Assignees

• Univ British Columbia

Inventors

• Hein Jason Ellis
• Kennepohl Johannes Pierre

Classifications

• C01D15/08

  Carbonates; Bicarbonates · CPC title

• C22B26/12 Primary

  Obtaining lithium · CPC title

• Y02P20/133

  Renewable energy sources, e.g. sunlight · CPC title

• Y02P10/20

  Recycling · CPC title

• Y02E60/10

  Energy storage using batteries · CPC title