The rare-earth elements, or rare earths—the group of 17 chemical elements with atomic numbers 21, 39, and 57 through 71—are not truly rare in terms of their chemical abundance in the Earth’s crust. However, they are typically found in low concentrations in ore and mineral deposits, and the current supply of them is somewhat limited. Notwithstanding their scarcity, demand for them is great because of their applications in what are now largely throw-away technologies: cell phones, tablets, laptops, televisions, hybrid and electric vehicles, wind turbines, and solar cells. See also: Periodic table; Rare-earth elements; Rare-earth minerals
Despite their seeming potential for recycling, almost no consumer products containing rare earths are recycled because of the many challenges involved. For example, the concentrations of rare earths in cell phones are very low (less than one gram per phone), whereas concentrations of the valuable metals copper, gold, and silver in phones are higher than in mined ore. If the difficulty and costs of the metallurgical and chemical extraction processes are taken into account, recycling rare earths from old electronics (or e-waste, as it is known) is uneconomical. Moreover, the infrastructure for collecting, stockpiling, and recycling e-waste to recover rare earths as raw materials has not been developed. See also: Recycling technology
Nevertheless, economics aside, there are reasons for recycling rare earths. Limited recoverable reserves of them exist worldwide. In time, the available rare-earth ore quality will be too poor for economic extraction. Although the United States, South Africa, Canada, Australia, Brazil, India, Russia, South Africa, Malaysia, Malawi, and Vietnam have deposits of rare earths, China now supplies almost all the world’s needs but does so at a huge environmental cost. Rare-earth element deposits often contain the radioactive elements uranium and thorium, which makes mining, extraction, and waste disposal very hazardous processes. See also: Precious element resources; Radioactive minerals; Rare-earth mining
A number of positive recycling and replacement efforts are in development and operation. Osram AG in Germany, the Solvay Group in France, and AERC Recycling Solutions and Global Tungsten & Powders in the United States are recovering rare earths from fluorescent light bulbs. Perhaps the most important recycling effort is for the recovery of neodymium and dysprosium used in rare-earth (permanent) magnets for hard disk drives, compressors, speakers, hybrid and electric-vehicle motors, and wind turbines. Research efforts to recycle neodymium and dysprosium are in progress at the Ames Laboratory in the United States as well as at Dowa Metals & Mining, Mitsubishi, and Hitachi in Japan. See also: Dysprosium; Electric vehicle; Hybrid automotive power systems; Magnet; Neodymium; Wind turbines
In addition to recycling rare earths, other solutions for making the most of the reserves include improving the efficiency of their use and implementing replacement technology. Nissan, for example, found that it could cut its dysprosium use by 40% in the magnets used to power its Leaf electric vehicle’s electric motor. Tesla Motors has gone even further by using a copper-rotor induction motor that contains no rare earths in its Model S electric vehicle, and it is supplying this motor to Toyota for use in its RAV4 electric vehicle. Copper-rotor induction motors use more available materials and are inherently recyclable using existing technology. See also: Induction motor
