# US 2020/0399735 A1 · Lithium extraction > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2020/0399735 A1 - Document ID: US20200399735A1 - Status: Published application - Kind: A1 - Application number: 16/904,686 - Filed: 2020-06-18 - Published: 2020-12-24 - Earliest claimed: 2019-06-18 - Assignees: Schlumberger Technology Corporation - Applicants: Schlumberger Technology Corporation - Inventors: Gary W. Sams; Robert Charles William Weston; Ankur D. Jariwala - Web page: https://patentgrep.com/patent/US20200399735A1 ## CPC - C22B 3/02: Apparatus therefor - C22B 3/22: by physical processes, e.g. by filtration, by magnetic means {, or by thermal decomposition} (treatment or purification of solutions by liquid-liquid extraction C22B3/26) - C22B 26/12: Obtaining lithium - C22B 59/00: Obtaining rare earth metals - Y02P 10/20: Recycling - C22B: PRODUCTION AND REFINING OF METALS (electrolytic C25); PRETREATMENT OF RAW MATERIALS - Y02P: CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS ## Abstract Apparatus and methods for lithium extraction from aqueous sources are described herein. Divalent ions are removed using staged membrane separation. The aqueous source is subjected to a solvent extraction process that extracts lithium. Aqueous and organic phases of streams produced by the solvent extraction process are separated using electrical and/or gas flotation separation. The solvent is de-complexed to unload lithium. Streams produced by the de-complexing may be subjected to electrical and/or gas flotation separation. Solvent de-complexing can be performed using an electrical separator. Aqueous streams are pH adjusted for return to the environment. ## Claims ### Claim 1 An apparatus, comprising: a solvent contactor having a brine inlet at a first end of the solvent contactor, a solvent inlet at a second end of the solvent contactor opposite from the first end, a loaded solvent outlet at the first end of the solvent contactor, and a brine outlet at the second end of the solvent contactor; an electrical separator comprising a vessel fluidly coupled to the loaded solvent outlet, the vessel having an electric field assembly disposed in an interior thereof and electrically coupled to a time-varying voltage power unit, a loaded solvent outlet in an upper portion thereof, and a brine outlet in a lower portion thereof; and an extractor fluidly coupled to the loaded solvent outlet of the electrical separator, the extractor having a loaded solvent inlet, an unloaded solvent outlet, and a slurry outlet, with a sulfuric acid source coupled to the extractor. ### Claim 2 (depends on 1) The apparatus of claim 1, wherein the brine outlet of the solvent contactor is fluidly coupled to a first gas flotation separator. ### Claim 3 (depends on 1) The apparatus of claim 1, wherein the slurry outlet is fluidly coupled to a second gas flotation separator. ### Claim 4 (depends on 1) The apparatus of claim 1, further comprising a membrane separator fluidly coupled to the brine inlet of the solvent contactor, the membrane separator having a first membrane unit with a first permeate stream and a first reject stream, and a second membrane unit fluidly coupled to the first reject stream, the second membrane unit having a second permeate stream that combines with the first permeate stream to form a brine feed stream for the solvent contactor. ### Claim 5 (depends on 4) The apparatus of claim 4, further comprising a pre-filtration unit fluidly coupled to a brine inlet of the membrane separator. ### Claim 6 (depends on 2) The apparatus of claim 2, wherein the first gas flotation separator has a brine outlet coupled to a first filtration unit with an oleophilic filter material. ### Claim 7 (depends on 3) The apparatus of claim 3, wherein the second gas flotation separator has a lithium slurry outlet coupled to a second filtration unit having an oleophilic filter material. ### Claim 8 (depends on 1) The apparatus of claim 1, further comprising a second electrical separator fluidly coupled to the unloaded solvent outlet. ### Claim 9 (depends on 8) The apparatus of claim 8, further comprising a membrane separator fluidly coupled to the brine inlet of the solvent contactor, the membrane separator having a first membrane unit with a first permeate stream and a first reject stream, and a second membrane unit fluidly coupled to the first reject stream, the second membrane unit having a second permeate stream that combines with the first permeate stream to form a brine feed stream for the solvent contactor and a concentrated divalent stream. ### Claim 10 (depends on 9) The apparatus of claim 9, wherein the brine outlet of the contactor is fluidly coupled to a gas flotation separator having a brine outlet coupled to a filtration unit with an oleophilic filter material. ### Claim 11 (depends on 10) The apparatus of claim 10, wherein the second electrical separator has a brine outlet, and further comprising a first pH adjustment coupled to the brine outlet of the second electrical separator, a second pH adjustment coupled to a brine outlet of the filtration unit coupled to the gas flotation separator, and a third pH adjustment coupled to the concentrated divalent stream. ### Claim 12 An apparatus, comprising: a solvent contactor having a brine inlet at a first end of the solvent contactor, a solvent inlet at a second end of the solvent contactor opposite from the first end, a loaded solvent outlet at the first end of the solvent contactor, and a brine outlet at the second end of the solvent contactor; and an electrical separator arranged to treat loaded solvent from the solvent contactor, the electrical separator having an electrode disposed in an interior of a separation vessel and electrically coupled to a time-varying voltage power unit, a loaded solvent outlet in an upper portion of the separation vessel, and a brine outlet in a lower portion of the separation vessel. ### Claim 13 (depends on 12) The apparatus of claim 12, further comprising a de-complexing agent source fluidly coupled to the electrical separator at an inlet thereof. ### Claim 14 (depends on 13) The apparatus of claim 13, wherein the de-complexing agent source is fluidly coupled to the electrical separator at a location upstream of an inlet of the electrical separator. ### Claim 15 (depends on 13) The apparatus of claim 13, wherein the brine outlet of the solvent contactor is fluidly coupled to a gas flotation separator. ### Claim 16 (depends on 12) The apparatus of claim 12, further comprising a membrane separator fluidly coupled to the brine inlet of the solvent contactor, the membrane separator having a first membrane unit with a first permeate stream and a first reject stream, and a second membrane unit fluidly coupled to the first reject stream, the second membrane unit having a second permeate stream that combines with the first permeate stream to form a brine feed stream for the solvent contactor. ### Claim 17 (depends on 16) The apparatus of claim 16, wherein the second membrane unit also forms a concentrated divalent stream, the brine outlet of the solvent contactor is fluidly coupled to a gas flotation separator that produces a filtered clean brine stream, and further comprising a first pH adjustment coupled to the concentrated divalent stream and a second pH adjustment coupled to the filtered clean brine stream. ### Claim 18 (depends on 12) The apparatus of claim 12, wherein the solvent contactor is a rotary contactor. ### Claim 19 A method of recovering alkali metals from an aqueous source, comprising: removing divalent ions from the aqueous source by subjecting the aqueous source to a first membrane filtration process that produces a first permeate stream and a reject stream, routing the reject stream to a second membrane filtration process that produces a second permeate stream and a concentrated divalent stream, and combining the first and second permeate streams to produce a divalent depleted stream; contacting the divalent depleted stream with an organic solvent that complexes alkali metals and recovering a loaded solvent stream and a depleted brine stream; and de-complexing the loaded solvent of the loaded solvent stream in the presence of a time-varying electric field to form an aqueous stream and an unloaded solvent stream. ### Claim 20 (depends on 19) The method of claim 19, further comprising electrically dehydrating the loaded solvent stream prior to the de-complexing. ### Claim 21 (depends on 19) The method of claim 19, further comprising performing a gas flotation separation process on the depleted brine stream. ### Claim 22 (depends on 19) The method of claim 19, further comprising performing a gas flotation separation process on the aqueous stream. ### Claim 23 (depends on 19) The method of claim 19, further comprising pH adjusting the concentrated divalent stream and the depleted brine stream. ### Claim 24 (depends on 19) The method of claim 19, further comprising electrically dehydrating the unloaded solvent stream.