# US 12,218,325 B2 · Process for removing impurities in the recycling of lithium-ion batteries > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 12,218,325 B2 - Document ID: US12218325B2 - Status: Granted - Kind: B2 - Application number: 18/379,807 - Filed: 2023-10-13 - Published: 2024-02-08 - Granted: 2025-02-04 - Earliest claimed: 2020-08-24 - Assignees: Green Li-Ion Pte. Ltd. - Applicants: Green Li-Ion Pte. Ltd. - Inventors: Reza Katal - Web page: https://patentgrep.com/patent/US12218325B2 ## CPC - H01M 10/54: Reclaiming serviceable parts of waste accumulators - B09B 3/70: Chemical treatment, e.g. pH adjustment or oxidation (involving an extraction step B09B3/80) - C22B 3/46: by substitution, e.g. by cementation - C22B 7/007: {by acid leaching} - C22B 23/043: {Sulfurated acids or salts thereof} - C22B 23/0461: {by chemical methods} - C22B 26/12: Obtaining lithium - B09B 3/80: involving an extraction step - B09B 2101/16: Batteries - Y02P 10/20: Recycling - Y02W 30/84: Recycling of batteries or fuel cells - H01M: PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY - B09B: DISPOSAL OF SOLID WASTE NOT OTHERWISE PROVIDED FOR - C22B: PRODUCTION AND REFINING OF METALS (electrolytic C25); PRETREATMENT OF RAW MATERIALS - Y02P: CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS - Y02W: CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO WASTEWATER TREATMENT OR WASTE MANAGEMENT ## Abstract A method of treating a leaching solution derived from a black mass from spent lithium-ion batteries comprising setting pH of the leaching solution to about pH 1.2 to 2.5, adding iron powder to induce copper cementation, adding lime after copper cementation, and after adding lime, transiting pH of the leaching solution to about pH 6 to extract calcium fluoride, titanium hydroxide, aluminium hydroxide, iron hydroxide, and iron phosphate. A black mass recycling system comprising an impurity removal reactor configured to receive a sodium hydroxide feed, an iron powder feed, and a lime feed. ## Claims ### Claim 1 A method of treating a leaching solution, the method comprising: setting pH of the leaching solution to at least about 1.2, wherein the leaching solution is derived from a black mass comprising fluorine and phosphorous; adding iron powder to induce copper cementation; after copper cementation, adding lime; and after adding lime, increasing pH of the leaching solution to extract calcium fluoride, and iron phosphate. ### Claim 2 (depends on 1) The method according to claim 1, wherein about 2.5 g of iron powder is added for each litre of the leaching solution and/or is added over a period of about 15 minutes. ### Claim 3 (depends on 1) The method according to claim 1, wherein the lime is calcium oxide and about 20-40 g of calcium oxide is added for each kg of black mass or the lime is calcium hydroxide and about 30-60 g of calcium hydroxide is added for each kg of black mass. ### Claim 4 (depends on 1) The method according to claim 1, wherein the leaching solution is derived from the black mass by leaching the black mass with an inorganic acid and hydrogen peroxide. ### Claim 5 (depends on 4) The method according to claim 4, wherein the inorganic acid and hydrogen peroxide are added in consecutive order. ### Claim 6 (depends on 4) The method according to claim 4, wherein the black mass, inorganic acid, and hydrogen peroxide are agitated for a period of 1 hour. ### Claim 7 (depends on 4) The method according to claim 4, wherein the inorganic acid comprises sulfuric acid or hydrochloric acid. ### Claim 8 (depends on 7) The method according to claim 7, wherein the sulfuric acid is 4M sulfuric acid and about 6 litres of sulfuric acid is added for each kg of the black mass. ### Claim 9 (depends on 8) The method according to claim 8, further comprising diluting the sulfuric acid to about 2M by adding deionised water after a period of 1 hour. ### Claim 10 (depends on 1) The method according to claim 1, wherein the increasing pH of the leaching solution comprises adding sodium hydroxide to the leaching solution to increase pH of the leaching solution to about 6. ### Claim 11 (depends on 1) The method according to claim 1, further comprising extracting titanium hydroxide, aluminium hydroxide, and iron hydroxide, wherein the black mass further comprises iron, copper, titanium, and aluminium. ### Claim 12 A method of treating a leaching solution, the method comprising: setting pH of the leaching solution to at least about 1.2, wherein the leaching solution is derived from a black mass comprising fluorine and phosphorous; adding lime; and increasing pH of the leaching solution to extract calcium fluoride, iron phosphate, and iron hydroxide. ### Claim 13 (depends on 12) The method according to claim 12, further comprising adding iron powder to induce copper cementation and adding the lime after copper cementation. ### Claim 14 (depends on 12) The method according to claim 12, wherein the lime is calcium oxide and about 20-40 g of calcium oxide is added for each kg of black mass or the lime is calcium hydroxide and about 30-60 g of calcium hydroxide is added for each kg of black mass. ### Claim 15 (depends on 12) The method according to claim 12, wherein the leaching solution is derived from the black mass by leaching the black mass with an inorganic acid and hydrogen peroxide. ### Claim 16 (depends on 15) The method according to claim 15, wherein the inorganic acid comprises sulfuric acid or hydrochloric acid. ### Claim 17 (depends on 12) The method according to claim 12, wherein the increasing pH of the leaching solution comprises adding sodium hydroxide to the leaching solution to increase pH of the leaching solution to about 6. ### Claim 18 (depends on 12) The method according to claim 12, further comprising extracting titanium hydroxide, and aluminium hydroxide, wherein the black mass further comprises iron, copper, titanium, and aluminium. ### Claim 19 A black mass recycling system comprising: a leaching reactor configured to receive an inorganic acid feed, a hydrogen peroxide feed, a deionised water feed, and a black mass feed comprising fluorine and phosphorous; an impurity removal reactor configured to receive a sodium hydroxide feed, a lime feed, and a leaching solution from the leaching reactor and comprising an outlet configured to remove calcium fluoride, iron phosphate, and iron hydroxide; and a first valved outlet associated with the leaching reactor providing fluid communication between the leaching reactor and the impurity removal reactor. ### Claim 20 (depends on 19) The black mass recycling system according to claim 19, wherein the black mass feed further comprises iron, copper, titanium, and aluminium and the impurity removal reactor is further configured to receive an iron powder feed.