Ever since China announced new import rules and restrictions to rare earth metals, it has been in the news extensively: mostly, about how a supply crunch can affect a number of manufacturing industries, from smartphones to windmills and electric vehicles.
But what exactly are rare earth minerals? How do they exist in nature? How are they mined? And how are they used? Here’s a closer look.
The 17 rare earth elements
Rare earths are a group of 17 metallic elements found near the center of the periodic table—specifically atomic numbers 21, 39, and 57 to 71. They’re known for their unique fluorescent, conductive, and magnetic properties.
When mixed in small amounts with common metals like iron, rare earths can greatly enhance performance. That’s why they play a crucial role in modern technologies—from smartphones and electric vehicles to wind turbines and defence systems.
What makes rare earth elements rare?
Despite the name, rare earth elements aren’t exactly scarce. In fact, some are as common in the earth’s crust as copper or tin. What makes them “rare” is how they occur. They are not found in concentrated deposits, but are dispersed, often mixed with one another or with radioactive elements like uranium and thorium, which makes extraction and processing difficult.
Extracting them efficiently is a challenge. Their similar chemical properties make them difficult to separate from each other and from surrounding materials. Purifying them is another complex process that requires large amounts of ore and current extraction methods generate significant environmental waste, including radioactive water, toxic fluorine compounds, and strong acids.
How they are mined
There are two main methods used to extract rare earth elements, and both pose serious risks to the environment.
The first method involves stripping away layers of topsoil, which is then transported to leaching ponds. Chemicals like ammonium sulfate and ammonium chloride are added to the extracted material to separate the valuable metals. This process, while effective, leads to severe environmental consequences. The use of strong chemicals can result in air pollution, accelerate erosion, and contaminate nearby groundwater sources.
The second method involves drilling directly into the ground by inserting PVC pipes and rubber hoses. Chemicals are pumped through these channels to flush the earth and release the rare earth elements, which are later processed in leaching ponds. While this technique avoids large-scale removal of topsoil, it poses the same risks of chemical pollution as the first method, and also leaves behind a trail of non-biodegradable plastic waste: pipes, hoses, and other equipment often abandoned in and around mining sites.
The overall environmental footprint of rare earth mining is staggering. For every ton of rare earth elements produced, the process releases approximately 13 kilograms of dust, 9,600-12,000 cubic meters of waste gas, 75 cubic meters of wastewater, and around one ton of radioactive residue.
*Generative AI via Venngage
These byproducts are a direct result of the interaction between naturally occurring metals in the ore and the chemicals used during processing. The consequence is widespread contamination of air, water, and soil, with long-term implications for both ecosystems and human health.
Why they are valued
Rare earth elements are valuable because of their unique physical and chemical properties, particularly their strong magnetism, high conductivity, and ability to emit light (luminescence). These traits make them essential to many modern technologies. From smartphones and electric vehicles to wind turbines, MRI machines and advanced military systems, rare earths play a critical role. Without them, much of today’s high-tech world simply wouldn’t function!
Where and how they are used
Rare earth elements are deeply woven into modern life — most of us use technology powered by REE in some form, every single day, ranging from the mundane to the cutting-edge. Here’s a look at some of the most sought-after rare earth elements, and where exactly they are used.
Neodymium (Nd)
Image courtesy of The Chemical Elements
- Loudspeakers, TVs, computer hard drives, electromagnetic generators, electric motors, EVs, wind turbines, lasers.
- Neodymium’s exceptional magnetic strength makes it ideal for compact, high-performance technologies.
- Neodymium-Iron-Boron alloy (Nd2Fe14B) makes the most powerful magnets in the world.
Praseodymium (Pr)
Image courtesy of Stanford Materials
- Aircrafts, fuel cells, carbon arc lights, fibre optics
- Praseodymium combines magnetic, electrical, and optical properties with excellent ductility. It’s used to create high-strength alloys with magnesium for aircraft engines, and plays a key role in fiber optic amplifiers, solid fuel cells, and specialized lighting for film and projection.
Samarium (Sm)
Image courtesy of The Chemical Elements
- Hybrid car motors, computer disk drives, speakers and headphones, specialised aircraft, military systems.
- Samarium is a strong, stable, and heat-resistant REE. Its key strength lies in its role in samarium-cobalt magnets—powerful, heat-resistant, and hard to demagnetise.
- These magnets enable miniaturised electronics like disk drives and headphones, and remain vital in high-temperature, high-reliability applications such as defence systems
Terbium (Tb)
Image courtesy of The Chemical Elements
- Colour TVs, SSD hard drives, sonar systems, high temperature fuel cells.
- Terbium’s unique luminescence and magnetic strength make it vital in modern technology.
- It brings vivid colour to screens, improves high-temperature performance in EV magnets, and strengthens metal alloys used in advanced electronics and precision lasers.
Cerium (Ce)
Image courtesy Umicore
- Glassmaking, petroleum refining, automotive catalytic converters,
- Cerium is the most abundant of the rare earth elements and prized for its chemical reactivity.
- Its oxide is widely used to polish glass and metals, decolorise glass, aid in petroleum refining, and enable self-cleaning oven technology.
Lanthanum (La)
Image courtesy of Stanford Advanced Materials
- Specialty glass, telescopes and microscopes, rifle optics, laptop and EV batteries, pharmaceuticals.
- Lanthanum’s strong reactivity makes it valuable across industries.When added to cast iron and to steel, lanthanum improves those materials’ capability to be shaped
- It enhances specialty glass for optics, improves the workability of metals, and serves as a catalyst in petroleum refining. It’s also used in EV batteries, wastewater treatment, and kidney disease medication (to reduce phosphate levels in patients).
Yttrium (Y)
Image courtesy Luciteria
- Strengthens metal alloys, industrial & agricultural lasers, medical instruments defence and missile defence systems
- Yttrium is a heat resistant and high-performance REE.
- Its superconducting properties make it essential in jet engines, red screen displays, and high-temperature alloys. It boosts fuel efficiency, reduces emissions, and powers lasers used in medicine, industry, and defence systems.
Gadolinum (Gd)
Image courtesy Stanford Advanced Materials
- X-Ray & MRI systems, TV screens, high refractive index glass, nuclear reactors.
- Gadolinium is known for its strong paramagnetism — it becomes magnetic only in the presence of an external magnetic field.
- Gadolinium’s strong paramagnetism makes it ideal for MRI and X ray contrast agents, enhancing image clarity. It resists high-temperature oxidation, strengthens industrial materials, absorbs neutrons in nuclear reactors, and improves glass quality and screen quality in TVs.
Europium (Eu)
Image courtesy The Chemical Elements
- TVs, visual displays, mobile phone screens, nuclear reactors.
- Europium is a rare earth element essential in modern lighting and display technologies.
- Europium’s strong luminescence makes it essential for vibrant red and blue colors in screens, LEDs, and fluorescent lamps. Its ability to absorb neutrons also makes it valuable in nuclear reactor control rods.
Dysprosium (Dy)
Image courtesy Institute of Rare Earths and Strategic Metals
- Lasers & infrared radiation, computer hard drives, nuclear reactors, drive motors of hybrid vehicles, fuel injectors.
- Dysprosium is known for its thermal stability and magnetic strength.
- Its properties make it vital for EV motors, wind turbine magnets, and hard drives. Its neutron absorption supports nuclear reactor control, while its use in lasers, sensors, and lighting highlights its broad tech utility.
Sources
News18: What Are Rare Earth Minerals
Rare Element Resources: Rare Earth Elements
Science History: History and Future of Rare Earth Elements
Reuters: What Are Rare Earth Elements
Harvard International Review: Not So “Green” Technology: The Complicated Legacy of Rare Earth Mining
Earth.org: How Rare Earth Mining Has Devastated China’s Environment