# US 9,751,067 B2 · Methods for purifying and recycling lead from spent lead-acid batteries > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 9,751,067 B2 - Document ID: US9751067B2 - Status: Granted - Kind: B2 - Application number: 14/498,748 - Filed: 2014-09-26 - Published: 2015-12-24 - Granted: 2017-09-05 - Earliest claimed: 2014-06-20 - Assignees: Johnson Controls Technology Company - Applicants: Johnson Controls Technology Company - Inventors: Matthew A. Spence - Web page: https://patentgrep.com/patent/US9751067B2 ## CPC - H01M 10/54: Reclaiming serviceable parts of waste accumulators - B01J 6/001: {Calcining} - B01J 6/002: {using rotating drums} - B01J 8/008: {Details of the reactor or of the particulate material; Processes to increase or to retard the rate of reaction (B01J8/0285, B01J8/067, B01J8/087, B01J8/1836 take precedence)} - B01J 19/06: Solidifying liquids (making microcapsules B01J13/02) - B01J 19/2465: {externally, i.e. the mixture leaving the vessel and subsequently re-entering it} - C22B 3/02: Apparatus therefor - C22B 3/04: by leaching (C22B3/18 takes precedence) - C22B 7/006: {Wet processes} - C22B 7/007: {by acid leaching} - C22B 7/009: {General processes for recovering metals or metallic compounds from spent catalysts (for recovering specific metals C22B11/00 - C22B61/00)} - C22B 13/04: {by wet processes} - C22B 13/045: {Recovery from waste materials} - H01M 6/52: Reclaiming serviceable parts of waste cells or batteries {, e.g. recycling} - B01J 2208/00805: Details of the particulate material - 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 - B01J: CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS - 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 The present disclosure relates to methods by which lead from spent lead-acid batteries may be extracted, purified, and used in the construction of new lead-acid batteries. A method includes: (A) forming a mixture including a carboxylate source and a lead-bearing material; (B) generating a first lead salt precipitate in the mixture as the carboxylate source reacts with the lead-bearing material; (C) increasing the pH of the mixture to dissolve the first lead salt precipitate; (D) isolating a liquid component of the mixture from one or more insoluble components of the mixture; (E) decreasing the pH of the liquid component of the mixture to generate a second lead salt precipitate; and (F) isolating the second lead salt precipitate from the liquid component of the mixture. Thereafter, the isolated lead salt precipitate may be converted to leady oxide for use in the manufacture of new lead-acid batteries. ## Claims ### Claim 1 A method, comprising performing the following steps in the recited order: (A) forming a mixture comprising a carboxylate source and a lead-bearing material disposed in a liquid component; (B) generating a lead carboxylate precipitate in the mixture as the carboxylate source reacts with the lead-bearing material; (C) increasing the pH of the liquid component of the mixture to dissolve the lead carboxylate precipitate into the liquid component of the mixture; (D) isolating the liquid component of the mixture from one or more insoluble components of the lead-bearing material in the mixture; (E) regenerating the lead carboxylate precipitate either by adding an antisolvent to the liquid component of the mixture or by adding an acid to decrease the pH of the liquid component of the mixture; and (F) isolating the regenerated lead carboxylate precipitate from the liquid component of the mixture. ### Claim 2 (depends on 1) The method of claim 1, comprising treating the isolated regenerated lead carboxylate precipitate using calcination or a base treatment to yield leady oxide. ### Claim 3 (depends on 2) The method of claim 2, wherein the leady oxide comprises between approximately 0% and approximately 35% free lead. ### Claim 4 (depends on 2) The method of claim 2, wherein the leady oxide comprises leady oxide particles having a D50 between approximately 0.2 μm and approximately 20 μm. ### Claim 5 (depends on 2) The method of claim 2, wherein the leady oxide has a Brunauer-Emmett-Teller (BET) surface area greater than approximately 2.5 square meters per gram (m2/g). ### Claim 6 (depends on 2) The method of claim 2, wherein the leady oxide has an acid absorption greater than approximately 250 milligrams H2SO4 per gram. ### Claim 7 (depends on 2) The method of claim 2, wherein the leady oxide comprises less than approximately 20% beta phase lead oxide. ### Claim 8 (depends on 2) The method of claim 2, comprising: forming an active material for use in a lead-acid battery, wherein the active material comprises the leady oxide; and constructing a battery comprising the active material. ### Claim 9 (depends on 1) The method of claim 1, comprising reacting one or more impurities from the lead-bearing material present in the liquid component of the mixture isolated in step (D) with at least one reducing agent to evolve one or more impurity gases that are released from the liquid component before step (E) to remove the one or more impurities from the liquid component, wherein the one or more impurities comprise an element or compound of Group 14, an element or compound of Group 15, an element or compound of Group 16, an element or compound of Group 17, or a combination thereof. ### Claim 10 (depends on 1) The method of claim 1, wherein the regenerated lead carboxylate precipitate includes less than approximately 0.1% sulfates. ### Claim 11 (depends on 1) The method of claim 1, comprising grinding one or more spent lead-acid batteries to generate the lead-bearing material. ### Claim 12 (depends on 1) The method of claim 1, wherein the carboxylate source comprises a Group 1 or Group 2 citrate, citric acid, ammonium citrate, a Group 1 or Group 2 acetate, ammonium acetate, acetic acid, or a combination thereof. ### Claim 13 (depends on 1) The method of claim 1, wherein increasing the pH of the mixture comprises raising the pH of the mixture above 7. ### Claim 14 (depends on 1) The method of claim 1, wherein increasing the pH of the mixture comprises raising the pH of the mixture to a value between approximately 8 and 14. ### Claim 15 (depends on 1) The method of claim 1, wherein increasing the pH of the mixture comprises adding a hydroxide to the mixture, wherein the hydroxide comprises a Group 1 or Group 2 hydroxide, ammonium hydroxide, or a combination thereof. ### Claim 16 (depends on 1) The method of claim 1, wherein the one or more insoluble components of the lead-bearing material in the mixture comprise barium sulfate, carbon black, glass, polymer, or combinations thereof. ### Claim 17 (depends on 1) The method of claim 1, wherein the one or more insoluble components of the lead-bearing material in the mixture include metallic parts comprising lead, antimony, arsenic, selenium, calcium, tin, silver, cadmium or a combination thereof. ### Claim 18 (depends on 9) The method of claim 9, wherein the one or more impurities comprise tellurium, antimony, tin, selenium, arsenic, germanium, silicon, phosphorus, sulfur, or a combination thereof. ### Claim 19 (depends on 9) The method of claim 9, wherein the at least one reducing agent comprises sodium tetraborohydride. ### Claim 20 (depends on 9) The method of claim 9, wherein the at least one reducing agent comprises sodium hydride. ### Claim 21 (depends on 9) The method of claim 9, wherein the at least one reducing agent comprises hydrogen gas. ### Claim 22 (depends on 9) The method of claim 9, wherein the at least one reducing agent comprises syngas. ### Claim 23 (depends on 9) The method of claim 9, wherein the one or more impurity gases comprise hydrogen telluride, antimony trihydride (stibine), tin tetrahydride (stannane), hydrogen selenide, arsenic trihydride (arsine), germanium tetrahydride (germane), silicon hydrides (silane), phosphine, hydrogen disulfide, or a combination thereof. ### Claim 24 (depends on 1) The method of claim 1, wherein the lead carboxylate precipitate is regenerated by adding the antisolvent to the isolated liquid component of the mixture in step (E), and wherein the antisolvent comprises: methanol, ethanol, propanol, ethylene glycol, or combinations thereof. ### Claim 25 (depends on 1) The method of claim 1, comprising: (G) recovering the antisolvent from the liquid component via distillation. ### Claim 26 (depends on 25) The method of claim 25, comprising: (H) recycling the antisolvent into step (E) to regenerate the lead carboxylate precipitate. ### Claim 27 (depends on 25) The method of claim 25, comprising: (H) recycling the liquid component into step (A) to facilitate leaching of lead solids. ### Claim 28 (depends on 25) The method of claim 25, comprising: (H) recycling the liquid component into step (C) to increase the pH of the mixture. ### Claim 29 (depends on 1) The method of claim 1, wherein the carboxylate source is a Group 1 or Group 2 citrate, citric acid, ammonium citrate, or a combination thereof, and wherein the lead carboxylate precipitate is lead citrate.