Recovery of Neodymium from Spent Hard Disk Drivers by Microwave Treatment and Magnesium Liquid Extraction
Rare earth elements (REEs) possess unique physical and chemical properties that render them indispensable in various industries, including electronics, energy production and storage, hybrid and electric vehicles, metallurgy, and petro-chemical processing. The criticality of REE underscores the need...
Saved in:
| Main Authors: | , , , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
MDPI AG
2025-01-01
|
| Series: | Magnetism |
| Subjects: | |
| Online Access: | https://www.mdpi.com/2673-8724/5/1/3 |
| Tags: |
Add Tag
No Tags, Be the first to tag this record!
|
| _version_ | 1850204438090743808 |
|---|---|
| author | Sabina Andreea Fironda Ioana Cristina Badea Marian Burada Radu-Robert Piticescu Lidia Licu |
| author_facet | Sabina Andreea Fironda Ioana Cristina Badea Marian Burada Radu-Robert Piticescu Lidia Licu |
| author_sort | Sabina Andreea Fironda |
| collection | DOAJ |
| description | Rare earth elements (REEs) possess unique physical and chemical properties that render them indispensable in various industries, including electronics, energy production and storage, hybrid and electric vehicles, metallurgy, and petro-chemical processing. The criticality of REE underscores the need to enhance the efficiency of primary resource extraction and promote circularity through increased recycling from secondary sources. This paper provides a brief overview of REE recovery from secondary sources, particularly waste from electronic and electric equipment (WEEE). The discussion encompasses direct reuse of magnets, short-loop recycling (direct recycling), hydro- and pyrometallurgical processes, highlighting microwave (MW) technology. Original results are presented, focusing on the recovery of neodymium (Nd) from permanent magnet scraps from hard disk drives (HDD-PC) using microwave-assisted liquid metal extraction (LME) with magnesium (Mg) as the extractant. The subsequent separation of Nd from the Mg-Nd alloy via vacuum Mg distillation that is reused in the process is described. The experimental study demonstrates that the LME process, conducted in a microwave furnace, is a viable method for recovering Nd from permanent magnet scraps, which are essential for reducing the environmental impact of REE extraction and promoting a circular economy. By separating Nd from the alloy through vacuum distillation (450–550 mmHg), at temperatures of 850–900 °C for 8 h, a Nd sponge with a content of 95–98 wt.% Nd was obtained. The extracted content of Nd in the Mg alloy increases with increasing temperature and holding time. It was found that ≈ 97% of the Nd in the scrap was extracted from 2 to 5 mm crushed scrap at 800 °C for 8 h, using a LiF-LiCl-MgF<sub>2</sub> protecting flux in a furnace Ar atmosphere. |
| format | Article |
| id | doaj-art-937d4e37d8bb497d8bf5efa8d4368ad3 |
| institution | OA Journals |
| issn | 2673-8724 |
| language | English |
| publishDate | 2025-01-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Magnetism |
| spelling | doaj-art-937d4e37d8bb497d8bf5efa8d4368ad32025-08-20T02:11:17ZengMDPI AGMagnetism2673-87242025-01-0151310.3390/magnetism5010003Recovery of Neodymium from Spent Hard Disk Drivers by Microwave Treatment and Magnesium Liquid ExtractionSabina Andreea Fironda0Ioana Cristina Badea1Marian Burada2Radu-Robert Piticescu3Lidia Licu4National Research and Development Institute for Non-Ferrous and Rare Metals—IMNR, 102 Biruinței Boulevard, 077145 Pantelimon, RomaniaNational Research and Development Institute for Non-Ferrous and Rare Metals—IMNR, 102 Biruinței Boulevard, 077145 Pantelimon, RomaniaNational Research and Development Institute for Non-Ferrous and Rare Metals—IMNR, 102 Biruinței Boulevard, 077145 Pantelimon, RomaniaNational Research and Development Institute for Non-Ferrous and Rare Metals—IMNR, 102 Biruinței Boulevard, 077145 Pantelimon, RomaniaNational Research and Development Institute for Non-Ferrous and Rare Metals—IMNR, 102 Biruinței Boulevard, 077145 Pantelimon, RomaniaRare earth elements (REEs) possess unique physical and chemical properties that render them indispensable in various industries, including electronics, energy production and storage, hybrid and electric vehicles, metallurgy, and petro-chemical processing. The criticality of REE underscores the need to enhance the efficiency of primary resource extraction and promote circularity through increased recycling from secondary sources. This paper provides a brief overview of REE recovery from secondary sources, particularly waste from electronic and electric equipment (WEEE). The discussion encompasses direct reuse of magnets, short-loop recycling (direct recycling), hydro- and pyrometallurgical processes, highlighting microwave (MW) technology. Original results are presented, focusing on the recovery of neodymium (Nd) from permanent magnet scraps from hard disk drives (HDD-PC) using microwave-assisted liquid metal extraction (LME) with magnesium (Mg) as the extractant. The subsequent separation of Nd from the Mg-Nd alloy via vacuum Mg distillation that is reused in the process is described. The experimental study demonstrates that the LME process, conducted in a microwave furnace, is a viable method for recovering Nd from permanent magnet scraps, which are essential for reducing the environmental impact of REE extraction and promoting a circular economy. By separating Nd from the alloy through vacuum distillation (450–550 mmHg), at temperatures of 850–900 °C for 8 h, a Nd sponge with a content of 95–98 wt.% Nd was obtained. The extracted content of Nd in the Mg alloy increases with increasing temperature and holding time. It was found that ≈ 97% of the Nd in the scrap was extracted from 2 to 5 mm crushed scrap at 800 °C for 8 h, using a LiF-LiCl-MgF<sub>2</sub> protecting flux in a furnace Ar atmosphere.https://www.mdpi.com/2673-8724/5/1/3circular economyrare earth elementspermanent magnetsrecyclingmicrowave meltingliquid metal extraction |
| spellingShingle | Sabina Andreea Fironda Ioana Cristina Badea Marian Burada Radu-Robert Piticescu Lidia Licu Recovery of Neodymium from Spent Hard Disk Drivers by Microwave Treatment and Magnesium Liquid Extraction Magnetism circular economy rare earth elements permanent magnets recycling microwave melting liquid metal extraction |
| title | Recovery of Neodymium from Spent Hard Disk Drivers by Microwave Treatment and Magnesium Liquid Extraction |
| title_full | Recovery of Neodymium from Spent Hard Disk Drivers by Microwave Treatment and Magnesium Liquid Extraction |
| title_fullStr | Recovery of Neodymium from Spent Hard Disk Drivers by Microwave Treatment and Magnesium Liquid Extraction |
| title_full_unstemmed | Recovery of Neodymium from Spent Hard Disk Drivers by Microwave Treatment and Magnesium Liquid Extraction |
| title_short | Recovery of Neodymium from Spent Hard Disk Drivers by Microwave Treatment and Magnesium Liquid Extraction |
| title_sort | recovery of neodymium from spent hard disk drivers by microwave treatment and magnesium liquid extraction |
| topic | circular economy rare earth elements permanent magnets recycling microwave melting liquid metal extraction |
| url | https://www.mdpi.com/2673-8724/5/1/3 |
| work_keys_str_mv | AT sabinaandreeafironda recoveryofneodymiumfromspentharddiskdriversbymicrowavetreatmentandmagnesiumliquidextraction AT ioanacristinabadea recoveryofneodymiumfromspentharddiskdriversbymicrowavetreatmentandmagnesiumliquidextraction AT marianburada recoveryofneodymiumfromspentharddiskdriversbymicrowavetreatmentandmagnesiumliquidextraction AT radurobertpiticescu recoveryofneodymiumfromspentharddiskdriversbymicrowavetreatmentandmagnesiumliquidextraction AT lidialicu recoveryofneodymiumfromspentharddiskdriversbymicrowavetreatmentandmagnesiumliquidextraction |