US 12,258,280 B2
Method for concentrating and purifying eluate brine for the production of a purified lithium compound
Bernard Roy Mack, Natick, MA (US)
Assigned to Veolia Water Solutions & Technologies Support, Saint-Maurice (FR)
Appl. No. 17/438,495
Filed by Veolia Water Solutions & Technologies Support, Saint-Maurice (FR); and Bernard Roy Mack, Natick, MA (US)
PCT Filed Mar. 9, 2020, PCT No. PCT/US2020/021640
§ 371(c)(1), (2) Date Sep. 13, 2021,
PCT Pub. No. WO2020/185645, PCT Pub. Date Sep. 17, 2020.
Claims priority of provisional application 62/817,624, filed on Mar. 13, 2019.
Prior Publication US 2022/0144655 A1, May 12, 2022
Int. Cl. C01D 15/08 (2006.01); B01D 9/00 (2006.01); B01D 15/36 (2006.01); B01D 61/02 (2006.01); B01D 61/42 (2006.01); B01D 61/44 (2006.01); B01D 61/58 (2006.01); B01J 47/12 (2017.01); C02F 9/00 (2023.01); C02F 1/04 (2023.01); C02F 1/42 (2023.01); C02F 1/44 (2023.01); C02F 1/469 (2023.01); C02F 1/52 (2023.01)
CPC C01D 15/08 (2013.01) [B01D 9/0031 (2013.01); B01D 15/362 (2013.01); B01D 61/025 (2013.01); B01D 61/027 (2013.01); B01D 61/029 (2022.08); B01D 61/422 (2013.01); B01D 61/44 (2013.01); B01D 61/58 (2013.01); B01J 47/12 (2013.01); C02F 9/00 (2013.01); B01D 2009/0086 (2013.01); B01D 2311/06 (2013.01); B01D 2311/08 (2013.01); B01D 2311/2512 (2022.08); B01D 2311/2523 (2022.08); B01D 2311/2623 (2013.01); B01D 2311/2642 (2013.01); B01D 2311/2673 (2013.01); C02F 1/04 (2013.01); C02F 1/42 (2013.01); C02F 2001/425 (2013.01); C02F 1/441 (2013.01); C02F 1/442 (2013.01); C02F 1/4693 (2013.01); C02F 1/52 (2013.01); C02F 2001/5218 (2013.01)] 5 Claims
 
1. A method of recovering lithium carbonate from a brine rich in lithium, sodium and chloride and having impurities in the form of hardness, sulfate, and silica, the method comprising:
directing the brine to a nanofiltration unit and subjecting the brine to nanofiltration and removing sulfate from the brine, along with hardness associated with the sulfate;
wherein after nanofiltration, the brine still contains silica and residual hardness and remains rich in lithium, sodium and chloride;
after nanofiltration, maintaining conditions in the brine that result in the silica being substantially non-ionized;
further after nanofiltration, directing the brine through an electrodialysis unit and subjecting the brine to an electrodialysis process and producing a concentrate rich in lithium, sodium and chloride and a product stream depleted in lithium, sodium and chloride but including the substantially non-ionized silica;
after subjecting the brine to the electrodialysis process, directing the concentrate to an ion-exchange unit and removing residual hardness from the concentrate;
after removing residual hardness from the concentrate, directing the concentrate of lithium, sodium and chloride to a precipitating unit and mixing a selected reagent with the concentrate and precipitating lithium carbonate; and
recovering the precipitated lithium carbonate.