Turning Magnetic Scrap Into Valuable Alloy.

• Position: Process developed at Department of Energy's Ames Laboratory - Brief Article - Statistical Data Included

Researchers at the U.S. Department of Energy's Ames (Iowa) Laboratory have refined a process that makes it commercially viable to recover a valuable rare-earth element from tons of stockpiled magnetic scrap. High-energy neodymium-iron-boron magnets are used extensively in automotive, consumer electronics, and biomedical applications with sales exceeding $2,000,000,000 per year. The superior performance of Nd-Fe-B magnets allows manufacturers to make electric motors smaller, more powerful, and more efficient, so everything from portable CD players and cordless drills to the motors driving automotive power windows can be lighter in weight and less draining on batteries.

The Nd-Fe-B material is quite brittle, so manufacturers wind up with a substantial amount of waste beyond the amount normally generated during machining and handling. Although this magnet scrap contains about 29% neodymium (by weight), the rare-earth element is valued at $30 per kilogram (or just slightly less per ounce than the price of silver), so it's worth recovering. The problem has been how to recover it.

"The magnet material oxidizes when heated to its melting point," notes Scott Chumbley, Ames Laboratory metallurgist and lead researcher on the project. "So it is not a simple matter to recycle. But it's too valuable to throw away, so there are literally warehouses full of 55-gallon drums of the stuff waiting to be recycled."

Until now, the best separation method available was to dissolve the Nd-Fe-B scrap in acid, then perform a series of chemical extraction and reduction steps. However, the complexity and expense of such a method was...