SELECTIVE RECOVERY OF RARE EARTH ELEMENTS FROM PERMANENT MAGNETS BY ELECTROCHEMICAL LEACHING AND ELECTRODEPOSITION
(iEdison No. 0685901-22-0028)

Patent ID: 10684 | Status: Filed

Abstract

Rare earth elements (REEs) are the 15 metals in the lanthanide series of the periodic table. They have very similar properties and are often found together in geologic deposits. Most of the REE today are produced outside the United States ( >80% being produced in China) and given that they are a key component in permanent magnets (PMs) used in clean energy technologies such as wind turbines, hybrid and electric vehicles, and other electromagnetic-to-mechanical conversion systems, as well as an essential component for optical drives and smartphones, they are deemed critical elements. As we work to rapidly transition to clean energy technologies, there is need for building a reliable domestic REE supply. One approach to sustainably increasing REE supply is through recycling of spent PMs. Existing methods for recycling magnets rely on pyrometallurgical or hydrometallurgical methods which need energy-intensive pretreatments or significant amounts of acid and chemical inputs—making them not sustainable. In contrast we report a promising new electrochemical method that is performed at room-temperature and without need for corrosives and can selectively recover REE from used PMs. We demonstrate the approach using a commercial neodymium-iron-boron (NdFeB) permanent magnet—one of the most widely used variety of magnets. We show selective Nd recovery, but the approach is also relevant to selective recovery of other REEs used in PMs. Our method involves selective electrochemical leaching of Nd from NdFeB permanent magnet followed by subsequent Nd electrodeposition on an electrode. Both steps are conducted using commercial organic electrolytes (Dimethylformamide, DMF) to ensure process scalability. We conducted experiments using commercial magnets to ensure results are transferable to industry. There are very few reported electrochemical methods for recycling, and they are all limited to aqueous acid based electrolytes—clearly distinguishing our work.

Application Number

18/300,313

Inventors

Lim,Hyung-Seok
Wang,Wei
Subban,Chinmayee
Murugesan,Vijay

Market Sector

Environmental
Energy Production and Efficiency
Chemistry and Catalysts
Biological Sciences and Omics