Recycling of rare earth magnet waste by removing rare earth oxide with molten fluoride

Osamu Takeda, Kiyotaka Nakano, Yuzuru Sato

Research output: Contribution to journalArticle

11 Citations (Scopus)

Abstract

Recycling of rare earth magnet scrap is required for improving resource conservation. Removal of rare earth oxide from off-specification magnet alloy scrap was investigated by remelting the scrap together with fluoride flux, LiF50 mol% NdF3 and LiF25 mol% NdF325 mol% DyF3, at 1503K for the development of novel recycling process. As a result, separation of magnet alloy from fluoride flux after remelting was fine, and neither suspension of alloy in the flux nor suspension of flux in the alloy was observed. Oxygen concentration of alloy decreased from 5000 to 160 mass-ppm by charging flux of 1.5 times of equivalent amount for complete dissolution of oxide. Substitution of neodymium in the alloy and dysprosium in the flux was observed. The investigated process should be utilized for mildly contaminated waste such as a used (endof-life) magnet because of simple process, energy saving and unlimited location.

Original languageEnglish
Pages (from-to)334-341
Number of pages8
JournalMaterials Transactions
Volume55
Issue number2
DOIs
Publication statusPublished - 2014 Feb 14

Keywords

  • Deoxidation
  • Fluoride
  • Magnet
  • Rare earth
  • Recycling

ASJC Scopus subject areas

  • Materials Science(all)
  • Condensed Matter Physics
  • Mechanics of Materials
  • Mechanical Engineering

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