Leaching of Rare Earth Elements from Neodymium magnet using Electrochemical method

Abstract

Neodymium magnets contain rare earth elements. In this study, rare earth elements were recovered from neodymium magnets using the molten salt electrolysis process, thereby making the existing recycling processes for neodymium magnets obsolete. Using anodic polarization, rare earth elements were leached by controlled potential electrolysis, without leaching iron and other elements. The composition of rare earth elements in the molten salt was more than 99 mass% from the controlled potential electrolysis process, not accounting for the molten salt component. Rare earth elements were leached from the boundary phase first. After electrolysis, the boundary phase disappeared from the residual, and rare earth elements were not detected in the residual. The Nd2Fe14B alloy was converted to other materials. The neodymium magnet decomposed with the leaching of the boundary phase and became brittle. It was shown that rare earth elements were leached in preference to other elements using controlled potential electrolysis

High Temperature Phase Relations of the Nd₂O₃-Na₂B₄O₇ Pseudo Binary System and Their Application to Recycling of Neodymium Magnets

“…，希土類元素を選択的に塩 化物として回収する方法 [16][17][18][19][20] ，溶融塩に希土類元素を抽出 し，溶融塩電解により金属として回収する方法 [21][22][23][24][25] ，Mg や…”