Professor Katsunori Yamaguchi of Iwate University developed a technology for effective recovery of rare earths from used magnets contained in the motors of eco-cars and home electronics in alliance with JX Nippon Mining and Metals. Currently, it is necessary to take off nickel plating by hand and break used motors into fragments, and subsequently found the fragments with hydrochloric acid. It takes one day to finish this process.
The new technology is to mix used magnets with boron and heat them to 1,200 degrees centigrade, and subsequently take them apart to recover neodymium and dysprosium that have a purity of higher than 99% in half the time required by the existing method at a lower cost. Heating the treated magnet to 1,200 degrees centigrade dissolves it into oxidized boron, composite containing neodymium and dysprosium, iron, carbon, and nickel alloy. And the recovered neodymium and dysprosium are burned at 400-500 degrees centigrade for one hour. In the experiment, the recovered rare earths had a purity of up to 99.5%. The professor is confident that this technology can be put to practical use when a process to eliminate harmful substances produced in recovery is established.
Recycling rare earths