What are rare-earth elements? A guide to REE mining and analysis
Rare-earth elements (REEs) are the backbone of many of the cutting-edge technologies that promise to make our world smarter and more sustainable. However, meeting the rising demand for rare earths isn’t easy, due to challenges in their extraction and processing.
In this blog, we’ll cover what rare-earth elements are, why they are increasing in importance, and how mining companies can overcome the challenges of mining rare-earth elements using cutting-edge elemental analysis.
Key facts
- Rare-earth elements, also known as “rare-earth metals” or “rare earths”, are seventeen metallic elements comprising fifteen lanthanides, plus scandium and yttrium.
- Rare-earth elements are not rare in quantity but are instead referred to as “rare” because of the difficulty of extracting them from their ores, which has contributed to a scarcity of REE mines around the world.
- Comprehensive and accurate elemental analysis, such as high-powered X-ray fluorescence (XRF) analysis, can assist with rare-earth element exploration, extraction, and processing.
What are rare-earth elements?
The rare-earth elements, sometimes called “rare-earth metals” or “rare earths”, are a set of seventeen metallic elements comprising the fifteen lanthanides, plus scandium and yttrium.
They form an essential part of many high-tech devices such as smartphones and electric vehicle (EV) motors and batteries, making them increasingly valuable, particularly as more countries commit to the energy transition. However, challenges in mining and processing rare earths mean that few countries have the infrastructure required to meet this demand.
Rare-earth elements on the periodic table
The majority of rare-earth elements appear on the periodic table as elements 58–71. Only Lanthanum (La), Yttrium (Y), and Scandium (Sc) do not appear in this row.
Why are rare-earth elements called “rare”?
Rare-earth elements are actually not “rare” due to a scarcity in nature. In fact, they are roughly as abundant as metals like copper and zinc. Instead, they are called “rare earths” for a few reasons:
- Low concentrations. Although they are relatively abundant, rare-earth elements do not often occur in high concentrations. This makes the mining process inefficient, as a lot of power is required to extract a relatively small quantity of rare-earth elements.
- High chemical stability. Rare-earth metals are also difficult to extract because they are very chemically stable, meaning it takes high-intensity processing to separate the metals from their ores.
- Hazards during processing. The necessity of high-intensity processing, combined with the frequently hazardous nature of the rare-earth elements themselves, means that there are many safety concerns associated with rare-earth element mining.
- Lack of infrastructure. These challenges mean that there are few places around the world with the infrastructure in place to extract rare-earth elements at scale.
Why are rare-earth elements so important now?
Rare-earth elements are so important now because they are essential to the manufacturing of many technologies that are essential to the energy transition.
The International Energy Agency predicts that in the production of low-carbon energy and EVs, the demand for neodymium alone could climb by more than 600%, from 4,900 tons in 2020 to 37,700 tons in 2040.
Other rare earths are also important in sustainable technology. For example:
- Wind turbines typically use magnets containing rare-earth elements such as praseodymium, dysprosium, and terbium alongside neodymium.
- EV motors use neodymium and samarium and sometimes also terbium and dysprosium.
- Solar panels sometimes utilize dysprosium and cerium to boost the efficiency and durability of their thin-film solar cells.
Where in the world can rare-earth elements be found?
Most of the world’s rare-earth elements come from China. The country has an estimated 44 million tons of rare-earth metals in reserve – that’s around 38% of total global reserves, more than any other country. China is also by far the world’s largest producer of rare-earth elements, responsible for almost 70% of global REE production in 2024.
This dominance is thanks not only to China’s substantial natural resources but also its low labor costs, government subsidies, and more relaxed environmental policies, which offset the costs associated with extracting and processing rare-earth metals.
These costs have historically prevented other countries from taking full advantage of their rare-earth element reserves. For instance, although Vietnam and Brazil have the second- and third-largest reserves of rare-earth metals, with 22 million tons and 21 million tons respectively, they each only produce around 1,000 tons of rare earths per year.
Governing bodies around the world are now striving to reduce their dependence on China for rare-earth elements by accelerating local rare-earth element mining projects. Two examples are the United States and the European Union.
What are rare-earth elements used for?
Rare-earth elements are used in the production of many advanced technologies, notably EV motors and magnets for offshore wind turbines. They are also used in other application areas – here’s a full run-down of rare-earth element applications.
| Application area | Rare-earth elements | Example usage |
|---|---|---|
| High-tech and magnet applications | Neodymium (Nd) | Permanent magnets |
| Praseodymium (Pr) | Magnets Aircraft engines Glasses | |
| Dysprosium (Dy) | Heat-resistant magnets in hybrid EV motors | |
| Terbium (Tb) | Green lasers Magnets | |
| Samarium (Sm) | Magnets for high temperature applications | |
| Gadolinium (Gd) | MRI contrast agents Nuclear control rods | |
| Lighting and displays | Europium (Eu) | Red phosphors in LEDs and screens |
| Terbium (Tb) | Green phosphors in screens and fluorescent lights | |
| Yttrium (Y) | LEDs Ceramics | |
| Metallurgy and alloys | Cerium (Ce) | Steel alloys Glass polishing Catalysts |
| Lanthanum (La) | Battery electrodes Camera lenses | |
| Mischmetal (a mixture of La, Ce, Nd, Pr) | Alloys Lighter flints | |
| Green technologies | Scandium (Sc) | Lightweight alloys for aerospace Fuel cells |
| Lanthanum (La), Cerium (Ce) | Catalysts in petroleum refining | |
| Nuclear and medical applications | Gadolinium (Gd) | Nuclear reactor control rods MRI |
| Lutetium (Lu) | Radiotherapy cancer treatment | |
| Promethium (Pm) | Nuclear batteries (very rare) |
The challenges of analyzing rare-earth elements during mining
Effective elemental characterization is critical to mining rare-earth elements. Whether during exploration, extraction, or processing, it is essential to know which elements are present and in what quantities, in order to tailor your operations and ensure a strong final product.
There are a few key challenges that arise when analyzing rare-earth elements:
- Geological diversity. Rare-earth elements are found in a range of geological environments – for instance, rare-earth elements can be found in beach sands, such as in Kerala, India, or in clay deposits like those in Guangxi, China. This means that there is no one-size-fits-all analytical process or workflow for mining rare-earth metals.
- Elemental similarity. Most of the rare-earth elements are chemically very similar; they frequently occur together and often in very low concentrations. This makes it challenging to analyze them using a technique such as conventional XRF, as spectral overlap could obscure the results. You therefore need high-powered XRF to achieve clear analysis.
- Safety risks to operators. Powerful analysis can sometimes present health and safety risks to operators – for example, in the case of inductively coupled plasma (ICP) analysis – and the elements themselves are often radioactive, posing further risks to operator safety.
- Long feedback loops. The complexity and extensive infrastructure required for rare-earth element characterization mean that analysis methods are often time-consuming and occur at a distance from the extraction site, lengthening the feedback loop for process monitoring and optimization.
However, there are instruments that can overcome these challenges.
Analysis methods for each stage of rare-earth metals mining
Each stage of mining rare-earth elements has different analytical needs. Here are the analytical techniques and instruments that rare-earth metals professionals should consider for each process stage.
Rare-earth element exploration
Portability is a key factor in elemental analysis during rare-earth element exploration, helping investigate diverse geological sites.
However, conventional portable XRF instruments usually have maximum X-ray tube voltages of 50kV. This means that while these instruments can measure light rare earths, they struggle to practically measure heavy rare-earth elements due to inadequate excitation and spectral overlaps with common metals such as iron and nickel.
The PowerHouse from SciAps helps overcome these obstacles. Designed specifically for rare-earth element exploration, the PowerHouse offers:
- An 80kV miniature X-ray tube
- The ability to measure both light and heavy REEs and pathfinder elements
- Measurements for 25 other elements important to mining and exploration
- Cloud connection, plus two cameras
- A battery life of more than six hours
- Safety and intuitive interface for operators
This helps you close the feedback loop during exploration, allowing you to analyze deposits in the field without waiting for results from the lab.
Find out more about the SciAps PowerHouse here.
Rare-earth element extraction
At the point of extraction, it is important for mining operators to have a general understanding of the content of their ores in order to tailor their process steps or, if necessary, adjust the content of their raw mix.
On-line analysis is key here. While it doesn’t offer the same precision as lab-based methods, it offers instant insights that can help operators spot trends in the ores coming down their process lines, helping them adjust their processing techniques.
The CNA Pentos or CNA3 cross-belt analyzers are strong candidates for this kind of analysis, offering:
- Effective pulsed fast and thermal neutron activation (PFTNA) analysis
- High-frequency analysis of the bulk of your raw material
- Insight into your ores without needing operators to approach potentially dangerous materials on the process line
- Automated radiation protection system (ARPS) to protect your workers
Learn more about the CNA range here.
Rare-earth element processing
Finally, rare-earth ores require heavy processing to separate and purify their components. Efficient and frequent or even real-time analysis can help optimize these processes and reduce costs, helping widen profit margins for rare-earth element mines. Here are three analysis methods to consider:
- Epsilon Xflow. The Epsilon Xflow is an on-line energy-dispersive XRF (EDXRF) analyzer designed for real-time elemental analysis of liquids. It offers significant advantages for REE processing, for instance, continuously monitoring the solutions used to leach rare-earth elements. This helps you optimize reagents, minimizing costs and environmental impact.
- Zetium. Our Zetium wavelength-dispersive XRF (WDXRF) instrument enables highly precise and reproducible multi-element analysis of solid samples. This is useful during final quality control of individual rare-earth concentrates and oxides, helping you ensure that they meet purity specifications and customers’ needs. However, it is not suitable for every REE.
- Aeris. Our compact X-ray diffraction (XRD) system is especially useful during beneficiation, helping operators monitor changes to mineralogy throughout processes such as chemical leaching and flotation.
Analysis methods for rare-earth elements mining: Summary table
In a hurry? Here’s a quick breakdown of the analysis methods available for mining rare-earth elements.
| Mining stage | Instrument | Technology | Summary |
|---|---|---|---|
| Exploration | PowerHouse | XRF | Portable, high-intensity XRF for fast, precise, in-field analysis |
| Extraction | CNA Pentos | PFTNA | High-frequency analysis of the bulk of your raw material |
| Processing | Epsilon Xflow | EDXRF | On-line EDXRF for real-time elemental analysis of liquids, for instance, during leaching |
| Zetium | WDXRF | Precise and reproducible multi-element analysis of solid samples; especially useful during quality control | |
| Aeris | XRD | Compact XRD, useful for monitoring mineralogical changes during beneficiation |
Tailored analysis for your rare-earth elements mine
Rare-earth elements are in increasing demand. As the energy transition and technological development continue at breakneck speed, countries around the world are ramping up the pressure on rare-earth metals mining.
To keep up with this demand, the professionals mining rare earths need precise tools to help them analyze their materials and optimize their processes. At Malvern Panalytical, we have the expertise and the broad portfolio required to not only power up your processes, but to create a tailored mining solution for your rare-earth element extraction site.
Find out more about our mining solutions here.
Further reads
- What are rare-earth elements? A guide to REE mining and analysis
- 6 Precious metal analysis methods using advanced analytical technologies
- Optimizing XRD throughput with the Aeris High-Capacity Sample Changer: Key insights from our webinar
- Optimize your XRD throughput with the Aeris High-Capacity Sample Changer
- Remote analysis: the near future of mining
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