Purification of Lithium-Containing Brine

Patent metadata

Field	Value
Publication number	US-2018353907-A1
Application number	US-201515736540-A
Country	US
Kind code	A1
Filing date	Oct 16, 2015
Priority date	Jun 24, 2015
Publication date	Dec 13, 2018
Grant date	—

Abstract

A process for removing at least Ca2+ and Mg2+ from a lithium-containing brine. The process comprises (i) providing an aqueous lithium-containing brine feed comprising dissolved Ca2+ and Mg2+ impurities in a weight ratio of Li+:Ca2+ of about 4:1 to 50:1 wt/wt and in a weight ratio of Li+:Mg2+ of about 4:1 to 50:1; (ii) subjecting said brine feed to nanofiltration to produce a lithium-containing permeate from which Ca2+ and Mg2+ components are being removed concurrently; and (iii) conducting the nanofiltration so that a separation occurs and a retentate solution is formed with a total amount of Ca2+ and Mg2+ of at least 75% of the total amount of Ca2+ and Mg2+ in the original aqueous lithium-containing brine feed and forming an aqueous lithium-containing permeate solution in which the total content of dissolved Ca2+ and Mg2+ is decreased to 25% or less as compared to the original aqueous lithium-containing brine feed.

First claim

1 . A process for removing divalent ions comprised at least of Ca 2+ and Mg 2+ from a lithium-containing brine, which process comprises
(i) providing an aqueous lithium-containing brine feed comprising at least Ca 2+ and Mg 2+ impurities in solution and in a weight ratio of dissolved Li + :Ca 2+ in the range of about 4:1 to about 50:1 wt/wt and in a weight ratio of dissolved Li + :Mg 2+ in the range of about 4:1 to about 50:1; (ii) subjecting said lithium-containing brine feed to nanofiltration to produce a lithium-containing permeate from which Ca 2+ and Mg 2+ components are being removed concurrently; and (iii) conducting the nanofiltration to cause a separation in which a retentate solution is formed with a total amount of Ca 2+ and Mg 2+ of at least 75% as compared to the total amount Ca 2+ and Mg 2+ in the original aqueous lithium-containing brine feed and forming an aqueous lithium-containing permeate solution in which the total content of dissolved Ca 2+ and Mg 2+ has been decreased such that the total content thereof is 25% or less as compared to the original aqueous lithium-containing brine feed.

2 . A process as in claim 1 wherein the aqueous lithium-containing brine used as the feed in (i) has an initial content of at least 200 ppm (wt/wt) of Li + , an initial content of Ca 2+ of at least 25 ppm (wt/wt) and an initial content of Mg 2+ of at least about 25 ppm (wt/wt).

3 . A process as in claim 1 wherein the aqueous lithium-containing brine used as the feed in (i) has an initial content of at least 500 ppm (wt/wt) of Li + , an initial content of Ca 2+ of at least 25 ppm (wt/wt) and an initial content of Mg 2+ of at least about 25 ppm (wt/wt).

4 . A process as in claim 1 wherein the aqueous lithium-containing brine used as the feed in (i) has an initial content of at least 1000 ppm (wt/wt) of Li + , an initial content of Ca 2+ of at least 50 ppm (wt/wt) and an initial content of Mg 2+ of at least about 50 ppm (wt/wt).

5 . A process as in claim 1 wherein the nanofiltration is conducted using nanofiltration membranes which have not been treated with chemical compounds such as polyfunctional amines affecting the solute-removing performance and water permeation performance of particular ionic species through the membranes.

6 . A process as in claim 1 wherein the nanofiltration is conducted using at least one series of two or more nanofiltration units arranged in series.

7 . A process as in claim 1 wherein the nanofiltration is conducted using at least two or more nanofiltration units arranged in parallel.

8 . A process as in an claim 1 wherein the nanofiltration is conducted using one or more nanofiltration units in which the nanofiltration membranes contained therein are cellulose acetate membranes.

9 . A process as in claim 1 wherein the nanofiltration is conducted using one or more nanofiltration units in which the nanofiltration membranes contained therein are composed of at least one thin polyamide layer deposited on a polyethersulfone porous layer or a polysulfone porous layer.

10 . A process as in claim 1 wherein the nanofiltration units are arranged in series and wherein between some or all nanofiltration units, the lithium-containing feed solution is diluted with an aqueous solution to increase the rate of production of lithium-containing permeate solution while maintaining a minimum separation of 75% between Li + and Mg 2+ dissolved ions and between Li + and Ca 2+ dissolved ions.

11 . A process as in claim 1 wherein the aqueous lithium-containing brine provided in (i) has a content of at least 500 ppm (wt/wt) of Li + , a content of Ca 2+ of at least 25 ppm (wt/wt) and a content of Mg 2+ of at least about 25 ppm (wt/wt); and wherein the nanofiltration units are arranged in series and wherein between some or all nanofiltration units, the lithium-containing feed solution is diluted with an aqueous solution to increase the rate of production of lithium-containing permeate solution while maintaining a minimum separation of 75% between Li + and Mg 2+ dissolved ions and between Li + and Ca 2+ dissolved ions.

12 . A process as in claim 11 wherein the nanofiltration process is conducted using one or more nanofiltration units in which the nanofiltration membranes contained therein are cellulose acetate membranes.

13 . A process as in claim 11 wherein the nanofiltration is conducted using one or more nanofiltration units in which the nanofiltration membranes contained therein are composed of a thin polyamide layer deposited on a polyethersulfone porous layer or a polysulfone porous layer.

14 . A process as in claim 1 wherein the aqueous lithium-containing brine provided in (i) has a content of at least 1000 ppm (wt/wt) of Li + , a content of Ca 2+ of at least 50 ppm (wt/wt) and a content of Mg 2+ of at least about 50 ppm (wt/wt); and wherein the nanofiltration units are arranged in series and wherein between some or all nanofiltration units, the lithium-containing feed solution is diluted with an aqueous solution to increase the rate of production of lithium-containing permeate solution while maintaining a minimum separation of 75% between Li + and Mg 2+ dissolved ions and between Li + and Ca 2+ dissolved ions.

15 . A process as in claim 14 wherein the nanofiltration process is conducted using one or more nanofiltration units in which the nanofiltration membranes contained therein are cellulose acetate membranes.

16 . A process as in claim 14 wherein the nanofiltration is conducted using one or more nanofiltration units in which the nanofiltration membranes contained therein are composed of a thin polyamide layer deposited on a polyethersulfone porous layer or a polysulfone porous layer.

17 . A process as in claim 1 wherein the nanofiltration is applied to solutions derived from a Smackover brine.

18 . A process as in claim 17 wherein the contents of Li + , Ca 2+ , and Mg 2+ in the Smackover Brine are adjusted to provide said weight ratios of dissolved Li + :Ca 2+ and of dissolved Li + :Mg 2+ .

Assignees

• Albemarle Corp

Inventors

• Switzer Jackson R
• Cheng Chi Hung
• Alferi Steven R

Classifications

• B01D2317/022

  Reject series · CPC title

• B01J20/28035

  with more than one layer, e.g. laminates, separated sheets · CPC title

• B01D61/022 Primary

  Operations & Transport · mapped topic

• B01D2311/25

  Recirculation, recycling or bypass, e.g. recirculation of concentrate into the feed · CPC title

• B01D71/16

  Cellulose acetate · CPC title