Recovering Rare Earth Permanent Magnets for Reuse

EPA Grant Number: SU836785
Title: Recovering Rare Earth Permanent Magnets for Reuse
Investigators:
Institution: Purdue University
EPA Project Officer: Hunt, Sherri
Phase: I
Project Period: September 1, 2016 through August 31, 2017
Project Amount: $14,992
RFA: P3 Awards: A National Student Design Competition for Sustainability Focusing on People, Prosperity and the Planet (2016) RFA Text |  Recipients Lists
Research Category: Sustainability , P3 Awards , P3 Challenge Area - Materials & Chemicals

Description:

Develop an industrial-scale technology for recovering rare earth permanent magnets (REPMs) from motors and hard disk drives; explore options for reprocessing recovered REPMs for reuse or as new bonded magnets.

Objective:

Rare earth permanent magnets (REPMs) are essential components in many electrical and electronic products. Currently over 90% of the world’s rare earth elements (REEs) supply are produced in China. Recycling is one of the approaches to address this supply risk. To date, the recycling rate of REPMs has been very low and no industrial scale process has been established in the United States to recover REPMs from end-of-life products. One explanation for why REPMs have not retrieved is that it can be time consuming and expensive if the labor cost is high. This project aims to develop an industrial scale technology for profitably recovering and reusing REPMs.

Approach:

In this project, focus will be put on recovering REPMs from motors and hard disk drives (HDDs), and on exploring options of reprocessing recovered REPMs for reuse or as new bonded magnets. In the case of motors, the challenge of retrieving REPMs from the rotor comes from the strong magnetic force between the REPMs and the steel laminates, which makes it extremely time consuming to recover REPMs. To speed up the process, demagnetization will be attempted before REPMs recovery. Two approaches will be explored, i.e., heat treatment and AC current treatment. Preliminary experiments suggest that heat treatment at mild temperature can significantly weaken the magnetic force and make the recovery of REPMs very easy. In addition, a semi-automatic tool will be designed and tested, which will extract copper windings from the stator with minimal efforts and short time duration. In the case of HDDs, a punching tool/machine will be developed which can align the HDD according to the brand/manufacturer and cut the corner and the center with REPMs out in two movements. For the recovered REPMs, the team will explore the opportunities for the possibility of direct reuse in other products, especially for REPMs recovered from motors given the fact that they are not coated and have regular geometry. Pulverizing the recovered REPMs to make bonded magnets for niche markets will also be explored.

Expected Results:

Deliverables of this project include a technical pathway and a set of equipment/tools that will enable the recovery of REPMs from EOL products such as motors and HDDs. Field data will be collected to develop a business model to demonstrate the economic viability of REPMs recycling.

Supplemental Keywords:

Waste to value, electronic waste recycling, resource recovery, industrial ecology, life cycle analysis, cost benefit analysis.