Izdelava NdFeB magnetov z izboljšanimi magnetnimi lastnostmi iz recikliranega materiala

Jarc, Katja (author), Markoli, Boštjan (mentor)

Reciklaža NdFeB-magnetov postaja vse pomembnejša, saj je potreba po teh magnetih vse večja, zaloge redkih zemelj za izdelavo magnetov je vse manj, njihovo pridobivanje iz rud pa je okolju zelo škodljivo. Največ zanimanja je za proces reciklaže, pri katerem se odpadne magnete s hidrogeniranjem in mletjem s plinskim curkom neposredno predela v recikliran prah za izdelavo novih magnetov, kar je trenutno ekonomsko in ekološko najboljša rešitev za predelava magnetov. Večina raziskav reciklaže trenutno še vedno poteka na laboratorijskem nivoju, zato je postopek reciklaže v industrijskih pogojih le delno uspešen pri doseganju podobnih rezultatov magnetnih meritev. Zaradi slabe raziskanosti reciklaže odpadnih NdFeB-magnetov na nivoju industrijske predelave se to diplomsko delo osredotoča na izboljšavo remanence recikliranih magnetov z dodajanjem dodatkov za modifikacijo sestave in izdelavo končnega izdelka, ki vsebuje vsaj 30 % reciklata. V prvem delu praktičnega dela smo pripravili prah s pomočjo postopka hidrogeniranja in mletja. V drugem delu smo izvedli poizkuse z mešanicami z različnimi deleži dodatkov (NdHx in svež material) in preučili njihov vpliv na gostoto in magnetne lastnosti vzorcev. Na podlagi analiz poizkusov, izvedenih v drugem delu, smo v tretjem delu izdelali končne izdelke s čim višjo remanenco. Mikrostrukturo in magnetne lastnosti končnih izdelkov smo primerjali z odpadnimi magneti. S primerjavo smo lahko videli spremembe v mikrostrukturi in magnetnih lastnostih recikliranih magnetov, ki so odvisne predvsem od deleža reciklata.

• Language: Slovenian
• Keywords: reciklaža NdFeB odpadnih magnetov, tehnologija izdelave trajnih magnetov, metalurgija prahov, hidrogeniranje, izboljšava magnetnih lastnosti, mikrostruktura
• Work type: Bachelor thesis/paper
• Organization: NTF - Faculty of Natural Sciences and Engineering
• Year: 2017
• PID: 20.500.12556/RUL-94351
• COBISS.SI-ID: 1690719
• Publication date in RUL: 01.08.2017

JARC, Katja, 2017, Izdelava NdFeB magnetov z izboljšanimi magnetnimi lastnostmi iz recikliranega materiala [online]. Bachelor’s thesis. [Accessed 12 April 2025]. Retrieved from: https://repozitorij.uni-lj.si/IzpisGradiva.php?lang=eng&id=94351

Secondary language

• Language: English
• Title: Production of NdFeB magnets with improved magnetic properties using recycled material

Abstract

Establishing the recycling process of NdFeB magnets has become more important in recent years as the need for those magnets is increasing, but supplies of the ore containing rare earth elements (REE) are decreasing. Moreover, production of REE from ore is very harmful to the environment. The biggest interest lies in the ‘’magnet to magnet’’ recycling process where waste magnets are directly transformed by hydrogenation and jet milling into recycled powder for further production of new magnets, which is the economically and ecologically the best solution out of the current processing methods of magnets. Most studies on magnets recycling are still carried out on the laboratory scale, so the recycling process under industrial conditions is only partially successful in achieving similar magnetic measurement results. Due to poor research of recycling NdFeB waste magnets on the industry scale, this work will focus on improving the remanence of recycled magnets by adding additives to modify the composition and on the production of magnets containing at least 30% of recycled powder. In the first part of the experimental work, we turned waste magnets into fine powder with hydrogen decrepitation process and jet milling. In the second part, experiments were carried out with mixtures with different proportions of additives (NdHx and fresh material) and their effect on the density and magnetic properties of the samples was studied. Based on the analysis of the experiments carried out in the second part, we made final products with the highest possible remanence in the third part of the experimental work. Microstructure and magnetic properties of the finished products were compared with properties of the waste magnets. By comparing them, we could see changes in the microstructure and magnetic properties of recycled magnets, which are mainly dependent on the recyclable content.

• Keywords: recycling waste NdFeB magnets, permanent magnet production technology, powder metallurgy, hydrogen decrepitation, magnetic properties improvement, microstructure