University of Tokyo Develops New Technology to Recover Rare Earth Metal from Scrap Magnets

Copyright Institute of Industrial Science at the University of Tokyo

The Institute of Industrial Science at the University of Tokyo, Japan, announced on October 26, 2010, that it had succeeded in recovering neodymium (Nd) -- essential rare earth metal used in high performance permanent, magnets - directrly from scrap magnets from used devices.

The new technology makes it possible to selectively extract rare earth metal from used magnets containing neodymium by soaking them in an extracting agent (molten salt such as a chloride and iodide), and then heating it up to 1,000 degrees Celsius. The rare earth materials are then salified or iodized and seep into the molten salt. Through vacuum distillation (at 0.0002 atmospheres), the rare earth metal can be efficiently separated out and recovered, making it possible to extract rare earth metals from scrap mixed with iron, aluminum, copper, nickel, and other materials.

The existing wet process requires an acidic aqueous solution that generates large amounts of harmful liquid waste containing heavy metals, along with other thorny problems. In contrast, the new technology essentially provides eco-friendly recycling because it is based on the contamination-free dry process which does not produce any waste solution.

A reliable supply of the rare earth metal is crucial, because neodymium is indispensable to the nation's high-tech industry and for use in environmental technologies, but problems such as the often-remote location of the raw material resources is a challenge. Thus, practical applications of the new technology to recycle otherwise unusable magnet scraps to recover rare earth metals will be of huge significance.

Hitachi Launches R&D on Rare Earth Magnet Recycling (Related JFS article)
http://www.japanfs.org/en/pages/029912.html

Posted: 2011/03/04 06:00:15 AM