Increasing efficiency of solvent extractions of rare earth elements by magnetic fields

Increasing efficiency of solvent extractions of rare earth elements by magnetic fields | Research Square window.SnipcartSettings = { analytics: { enabled: false } }; (function() { var accessVector = localStorage.getItem('access_vector') || ''; window.dataLayer = window.dataLayer || []; if (accessVector) { window.dataLayer.push({ user: { profile: { profileInfo: { snid: accessVector } } } }); } })(); (function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start':new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0],j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src='https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f);})(window,document,'script','dataLayer','GTM-K279D39R'); Browse Preprints In Review Journals COVID-19 Preprints AJE Video Bytes Research Tools Research Promotion AJE Professional Editing AJE Rubriq About Preprint Platform In Review Editorial Policies Our Team Advisory Board Help Center Sign In Submit a Preprint Cite Share Download PDF Article Increasing efficiency of solvent extractions of rare earth elements by magnetic fields Kilian Ortmann, Alexander Bidmon, Kerstin Eckert, Zhe Lei This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-3546158/v1 This work is licensed under a CC BY 4.0 License Status: Published Journal Publication published 07 Nov, 2025 Read the published version in Communications Physics → Version 1 posted You are reading this latest preprint version Abstract A novel method for rare-earth (RE) separation that incorporate magnetic separation into solvent extraction is proposed and validated. Exposing the RE(III) concentration boundary layer to a tailored magnetic field ( B ), solutomagnetic convection is induced by the Kelvin force. The basic hypothesis pursued is the competing RE(III) extraction kinetics to be selectively enhanced consequently. To validate this in a first step, the cation exchange process of dysprosium, Dy(III), inside a Hele-Shaw configuration is studied using a 0.5 g, 4x5 mm sized magnet. The extraction kinetics is quantified in terms of the Sherwood number. Here, a nearly squared dependence is found on the Ra number, generalizing the Rayleigh number by inclusion of the Kelvin force. Laser optics combined with numerical simulations unveil three different flow stages, which conclude with a quasi-steady, large scale recirculation emerging from a symmetry break at a critical value of Ra . This re-circulation replaces depleted Dy(III) solution at the interface by fresh solution from the bulk. Exceptional RE(III) extraction kinetics were demonstrated for this regime, characterized by a reaction rate that increases more than 18-fold when the B intensity is doubled. Thus, a greener technological route towards rare-earth extraction with potentially superior selectivity is opened. Physical sciences/Physics/Fluid dynamics Physical sciences/Chemistry/Physical chemistry/Reaction kinetics and dynamics rare-earth trivalent ions (RE(III)) magnetic-assisted solvent extraction solutomagnetic convection Kelvin force magnetic susceptibility Full Text Additional Declarations There is NO Competing Interest. Cite Share Download PDF Status: Published Journal Publication published 07 Nov, 2025 Read the published version in Communications Physics → Version 1 posted You are reading this latest preprint version Research Square lets you share your work early, gain feedback from the community, and start making changes to your manuscript prior to peer review in a journal. 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Also discoverable on Platform About Our Team In Review Editorial Policies Advisory Board Help Center Resources Author Services Accessibility API Access RSS feed Manage Cookie Preferences © Research Square 2026 | ISSN 2693-5015 (online) Privacy Policy Terms of Service Do Not Sell My Personal Information {"props":{"pageProps":{"initialData":{"identity":"rs-3546158","acceptedTermsAndConditions":true,"allowDirectSubmit":false,"archivedVersions":[],"articleType":"Article","associatedPublications":[],"authors":[{"id":473206763,"identity":"bfbe8540-3a63-49b3-a2b6-61e68c8306e0","order_by":0,"name":"Kilian Ortmann","email":"","orcid":"","institution":"Institute of Fluid Dynamics, Helmholtz-Zentrum Dresden-Rossendorf (HZDR), Dresden, D-01328, Germany","correspondingAuthor":false,"prefix":"","firstName":"Kilian","middleName":"","lastName":"Ortmann","suffix":""},{"id":473206764,"identity":"259006e5-c907-4ec8-88b9-acd9ac3590e2","order_by":1,"name":"Alexander Bidmon","email":"","orcid":"","institution":"Institute of Processing Engineering and Environmental Technology, Technische Universität Dresden, Dresden, D-01069, Germany","correspondingAuthor":false,"prefix":"","firstName":"Alexander","middleName":"","lastName":"Bidmon","suffix":""},{"id":473206765,"identity":"ff714707-6d42-4559-89f7-6f171f0a8e79","order_by":2,"name":"Kerstin Eckert","email":"","orcid":"https://orcid.org/0000-0002-9671-8628","institution":"Institute of Fluid Dynamics, Helmholtz-Zentrum Dresden-Rossendorf (HZDR), Dresden, D-01328, Germany; 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Exposing the RE(III) concentration boundary layer to a tailored magnetic field (\u003ci\u003e\u003cb\u003eB\u003c/b\u003e\u003c/i\u003e), solutomagnetic convection is induced by the Kelvin force. The basic hypothesis pursued is the competing RE(III) extraction kinetics to be selectively enhanced consequently. To validate this in a first step, the cation exchange process of dysprosium, Dy(III), inside a Hele-Shaw configuration is studied using a 0.5 g, 4x5 mm sized magnet. The extraction kinetics is quantified in terms of the Sherwood number. Here, a nearly squared dependence is found on the Ra\u003csup\u003e*\u003c/sup\u003e number, generalizing the Rayleigh number by inclusion of the Kelvin force. Laser optics combined with numerical simulations unveil three different flow stages, which conclude with a quasi-steady, large scale recirculation emerging from a symmetry break at a critical value of Ra\u003csup\u003e*\u003c/sup\u003e. This re-circulation replaces depleted Dy(III) solution at the interface by fresh solution from the bulk. Exceptional RE(III) extraction kinetics were demonstrated for this regime, characterized by a reaction rate that increases more than 18-fold when the \u003ci\u003e\u003cb\u003eB\u003c/b\u003e\u003c/i\u003e intensity is doubled. Thus, a greener technological route towards rare-earth extraction with potentially superior selectivity is opened.","manuscriptTitle":"Increasing efficiency of solvent extractions of rare earth elements by magnetic fields","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2025-06-19 04:30:29","doi":"10.21203/rs.3.rs-3546158/v1","editorialEvents":[],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"communications-physics","isNatureJournal":true,"hasQc":false,"allowDirectSubmit":false,"externalIdentity":"commsphys","sideBox":"Learn more about [Communications Physics](http://www.nature.com/commsphys/)","snPcode":"","submissionUrl":"","title":"Communications Physics","twitterHandle":"","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"ejp","reportingPortfolio":"Communications Series","inReviewEnabled":true,"inReviewRevisionsEnabled":false}}],"origin":"","ownerIdentity":"a025e50b-68a3-489d-803d-7d5c99208bf7","owner":[],"postedDate":"June 19th, 2025","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"published-in-journal","subjectAreas":[{"id":50255566,"name":"Physical sciences/Physics/Fluid dynamics"},{"id":50255567,"name":"Physical sciences/Chemistry/Physical chemistry/Reaction kinetics and dynamics"}],"tags":[],"updatedAt":"2025-11-08T08:08:47+00:00","versionOfRecord":{"articleIdentity":"rs-3546158","link":"https://doi.org/10.1038/s42005-025-02393-7","journal":{"identity":"communications-physics","isVorOnly":false,"title":"Communications Physics"},"publishedOn":"2025-11-07 05:00:00","publishedOnDateReadable":"November 7th, 2025"},"versionCreatedAt":"2025-06-19 04:30:29","video":"","vorDoi":"10.1038/s42005-025-02393-7","vorDoiUrl":"https://doi.org/10.1038/s42005-025-02393-7","workflowStages":[]},"version":"v1","identity":"rs-3546158","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-3546158","identity":"rs-3546158","version":["v1"]},"buildId":"8U1c8b4HqxoKbykW_rLl7","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}