Talk about energy in the palm of your hand: Rare earth elements (REEs) are present in the technology that we use on a daily basis. They are among the key ingredients in everything from cell phones to computers, optical fibers to headphones, microphones to loudspeakers. REEs are to thank for making the screen displays across televisions, tablets and PCs so colorful and vivid—and for continually improving digital appliances by making them smaller, lighter, more efficient and more powerful.
When it comes to electronic applications, the uses of REEs are plentiful. REEs are utilized as phosphors in cathode ray tubes, fluorescent lamps and X-ray intensifying screens. High-purity REEs are consumed as phosphor activators—they determine the phosphor’s emission spectra—and as hosts, assisting in the conversion of absorbed energy into radiant energy. One REE in particular, europium, contributes heavily to this field as it produces red phosphors and ultimately allows for the creation of high definition visuals and saturated colors.
The revolution in display technologies has ushered in a new wave of REE usage. The upsurge in liquid crystal displays (LCDs), plasma screens and organic light-emitting diodes (OLEDs) relies on REEs and their phosphors to generate sharp imagery. REEs are, in fact, assuming an ever greater importance as we buy larger TV and computer screens, and replace them more frequently. Find out more about REEs and clean energy here.
REEs are central to fiber optic technologies with many communication applications. Optical glass fibers are doped, or covered with, with REE ions, notably neodymium, ytterbium, erbium, thulium, praseodymium and holmium. Doped optical glass fibers are most often the gain medium in fiber lasers and fiber amplifiers that carry the light being transmitted in the fiber.
Additionally, REEs are used in hard drives, cordless tools and guitar pickups. Due to their powerful magnetic properties and relative stability at high temperatures, REEs are particularly attractive when size or energy intensity would otherwise prove problematic for manufacturers. The remarkably strong neodymium is commonly used in the production of magnets (usually combined with iron and boron to create the final product). Lanthanum is also used, as well as small amounts of samarium, gadolinium, terbium, and dysprosium.
Lanthanum has been crucial to lanthanum and mischmetal (an alloy of rare earth metals) nickel-metal hydride (NiMH) rechargeable batteries that have, in the last decade, virtually replaced nickel-cadmium (NiCa) batteries. NiMH rechargeable batteries offer higher power than many types of batteries. The continued focus on renewable energy has driven REE use in this sector, due to the inclusion of NiMH batteries in hybrid vehicles.
Rare Earth Elements and Electronic Recycling
Educating consumers as well as industry participation in research and development are crucial ways to stress the importance of REE recycling. According to some estimates, only one percent of all rare earth minerals are recycled. Most REEs in everyday consumer products such as cell phones, hard drives and fluorescent lighting could be recovered and reused. Recycling REEs is a promising source of future material.