# US 2019/0169710 A1 · Method For Extracting Rare Earth Elements Contained In Permanent Magnets > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2019/0169710 A1 - Document ID: US20190169710A1 - Status: Published application - Kind: A1 - Application number: 16/306,612 - Filed: 2017-06-02 - Published: 2019-06-06 - Earliest claimed: 2016-06-03 - Assignees: Brgm - Applicants: Brgm - Inventors: Alain Seron; Nour-Eddine Menad; Dominique Breeze; Marc Gamet - Web page: https://patentgrep.com/patent/US20190169710A1 ## CPC - C22B 59/00: Obtaining rare earth metals - C22B 1/02: Roasting processes (C22B1/16 takes precedence) - C22B 7/007: {by acid leaching} - C22B 3/165: {with organic acids} - 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) - 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 The invention relates to a method for extracting rare earth elements contained in permanent magnets, which includes the steps of thermal treatment of the permanent magnet, crushing at the end of the thermal treatment in order to obtain particles with a size smaller than 2 mm, treatment by agitation of the particles in a solution containing an organic acid, and separation of the liquid phase from the solid phase ## Claims ### Claim 1 A process for extracting rare-earth elements contained in a permanent magnet of NdFeB type comprising the steps of: a) heat treating the permanent magnet at a temperature greater than or equal to its Curie temperature, b) grinding of the magnet resulting from the heat treatment step, the particles resulting from the grinding being classified in order to select the particles having, for 80% to 90% thereof, a size of less than 2 mm, c) treating, with stirring, the particles selected at the end of the grinding step with a solution containing an organic acid, d) separating a liquid phase from an optional solid phase at the end of the treatment with the solution containing the acid, e) separating the iron. ### Claim 2 (depends on 1) The process according to claim 1, the magnet particles resulting from the grinding having a size of less than 2 mm for 80% thereof. ### Claim 3 (depends on 1) The process according to claim 1, the organic acid being acetic acid, oxalic acid or citric acid, or a mixture thereof. ### Claim 4 (depends on 1) The process according to claim 1, the solution containing an organic acid being at a concentration ranging from 5% to 30% by volume. ### Claim 5 (depends on 1) The process according to claim 1, the treating with a solution containing the organic acid being carried out for a minimum duration of 1 hour. ### Claim 6 (depends on 1) The process according to claim 1, the iron being separated by precipitation. ### Claim 7 (depends on 1) The process according to claim 1, the iron being separated by being brought into contact with at least one material of biological origin. ### Claim 8 (depends on 7) The process according to claim 7, wherein the material of biological origin is oyster shell powder. ### Claim 9 (depends on 7) The process according to claim 7, wherein the material of biological origin is pine bark powder. ### Claim 10 (depends on 1) A recycling process incorporating the extraction process according to claim 1, wherein the permanent magnet originates from industrial waste. ### Claim 11 (depends on 1) The process according to claim 1, wherein rare earth elements have been added to the permanent magnet. ### Claim 12 (depends on 2) The process according to claim 2, wherein the magnet particles resulting from the grinding having a size of less than 2 mm for 90% thereof. ### Claim 13 (depends on 4) The process according to claim 4, wherein the solution containing an organic acid is at a concentration of 10%. ### Claim 14 (depends on 5) The process according to claim 5, wherein the treating with a solution containing and organic acid is carried out for less than 24 hours. ### Claim 15 (depends on 14) The process according to claim 14, wherein the treating with a solution containing and organic acid is carried out for 100 to 420 minutes. ### Claim 16 (depends on 15) The process according to claim 15, wherein the treating with a solution containing and organic acid is carried out for 420 minutes. ### Claim 17 (depends on 6) The process according to claim 6, wherein the iron is separated using introduction of oxygen or an oxygen containing gas. ### Claim 18 (depends on 17) The process according to claim 17, wherein the iron is separated using bubbling or mixing of oxygen or an oxygen containing gas. ### Claim 19 (depends on 17) The process according to claim 17, wherein the oxygen containing gas is air. ### Claim 20 (depends on 17) The process according to claim 17, wherein the iron is separated using pure oxygen.