Recovery of Rare Earth Elements from Magnets

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Track Code	2020-WANG-68878
Categories	Chemical Engineering Green Technology
Keywords	Chemical Engineering Circular economy Ligand-based chromatography Rare earth element
Public Abstract	Researchers at Purdue University have developed a method for the separation and purification of rare earth elements (REEs) from waste magnets. Magnets, which are used in electronics, automobiles, wind turbines, and other applications, contain three REEs—Pr, Nd, and Dy. The supply chain of REEs in general, and Pr, Nd, and Dy in particular, is at risk because the production of REEs is highly concentrated in a few countries. This invention presents two ligand-based chromatography (LBC) methods to produce high-purity (>99%) Nd, Pr, and Dy with high yields (>99%) and high productivity from crude REE mixtures derived from waste magnets. In the first method, termed ligand-assisted displacement (LAD), REEs are recovered in a ligand-associated elution step. In the second method, termed ligand-bound displacement (LBD), a ligand that is selective for other metal ions is immobilized on a stationary phase, enabling displacement separation of REEs. The LBC methods are applied in multiple zones, achieving a high-purity REE stream and mixed bands from the first zone. The mixed bands are then sent to the second zone for further separation, producing another high-purity REE stream and mixed bands. This process continues depending on the number of metal components to be separated. In a test of a two-zone LAD for the separation of Dy, Nd, and Pr, productivity was 111 kg REE/m3 sorbent/day, over 100 times higher than that of conventional extraction methods. Technology Validation: In both lab-scale and pilot-scale tests with mixtures of Dy, Nd, and Pr, this method produced separated REE streams with high purity, high yield, and high productivity. Advantages: - High purity, high yield, and high productivity recovery of REEs - Efficient and environmentally-friendly - Predictive and versatile design methods, applicable to different feedstocks, product specifications, and production scales - Enables circular economy for REEs Applications: - Recovery of REEs from waste magnets and other mixtures
People	Wang, Nien-hwa L (Project leader) Ding, Yi Harvey, David
Intellectual Property	Application Date Oct 28, 2022 Type NATL-Patent Country of Filing South Korea Patent Number (None) Issue Date (None) Application Date Sep 27, 2022 Type NATL-Patent Country of Filing Thailand Patent Number (None) Issue Date (None) Application Date Sep 26, 2022 Type NATL-Patent Country of Filing Australia Patent Number (None) Issue Date (None) Application Date Aug 26, 2022 Type NATL-Patent Country of Filing Japan Patent Number (None) Issue Date (None) Application Date Aug 5, 2022 Type NATL-Patent Country of Filing United States Patent Number (None) Issue Date (None) Application Date Jan 28, 2021 Type PCT-Gov. Funding Country of Filing WO Patent Number (None) Issue Date (None) Application Date Jan 28, 2021 Type NATL-Patent Country of Filing Canada Patent Number (None) Issue Date (None) Application Date Jan 28, 2021 Type NATL-Patent Country of Filing Europe Patent Number (None) Issue Date (None) Application Date Jan 28, 2021 Type NATL-Patent Country of Filing Vietnam Patent Number (None) Issue Date (None) Application Date Jan 28, 2021 Type NATL-Patent Country of Filing South Africa Patent Number (None) Issue Date (None) Application Date Feb 28, 2020 Type Provisional-Gov. Funding Country of Filing United States Patent Number (None) Issue Date (None)
Contact OTC	Purdue Office of Technology Commercialization The Convergence Center 101 Foundry Drive, Suite 2500 West Lafayette, IN 47906 Phone: (765) 588-3475 Fax: (765) 463-3486 Email: otcip@prf.org