Unlocking the power of Australia's rare earth elements

Demand for rare earth elements (REE) is soaring. According to the International Energy Agency's Global Critical Minerals Outlook 2024, global demand for magnet REE nearly doubled between 2015 and 2023. It has the potential to double again by 2050, in large part driven by the growth of clean energy technologies.

The Australian Critical Minerals Research and Development Hub brings together expertise from Australia's leading science agencies: CSIRO, the Australian Nuclear Science and Technology Organization (ANSTO) and Geoscience Australia, to scale up and commercialize Australia's critical minerals potential.

The three agencies are working together to accelerate the discovery, extraction and processing of REE from lower grade deposits. We are also exploring how to support industry stakeholders who are working downstream in the value chain.

Dr. Chris Vernon is our Critical Minerals Lead. He believes Australia has untapped potential with relatively substantial ore deposits, some of which are rich in high-grade ore. There are also several, previously overlooked resources that appear very promising. These include some very large but lower quality ores, by Australian standards.

"The mineralogy of some of these non-traditional ores makes them easier to process than the traditional ores, so there's a trade-off between grade, and ease of processing," Chris says.

"If we can then also develop the technology to move further along the value chain, that will bring some certainty and diversity to international supply chains. I think de-risking REE supply chains is going to be a key role for Australia."

Rare earth elements: A basic explainer

Rare earths are a group of 16 metallic elements that occur together in the periodic table. They include the 15 lanthanides plus yttrium.

Despite their name, REE are relatively plentiful in the earth's crust. However, they are typically quite dispersed and not found in high enough concentrations that make them viable to mine. As a group, REE are considered a specific subcategory of critical mineral.

"When we talk about critical minerals, that usually means a mineral that is difficult to get, either because of the economics or because of problems with supply chains," Chris says. "There are 31 critical minerals, and rare earths are included in there, but they also have distinct definitions within that group."

Rare earths are often described as being light or heavy. Light REE include lanthanum, cerium, praseodymium and neodymium. They appear towards the left of the periodic table and they are far more common.

In contrast, heavy REE are less common. They have higher atomic numbers and appear toward the right-hand side of the table and include elements like thulium, ytterbium and lutetium.

What all REE have in common—and what makes them so important as the world undergoes a rapid energy transition—is their strong optical or magnetic properties. Some of the rare earths, including samarium, praseodymium, neodymium, dysprosium and terbium make very strong magnets. They are a key component in the motors that drive wind turbines and electric vehicles.

Improving our knowledge of clay-hosted REE deposits

Researchers and industry already have a good understanding of the techniques for extracting and processing REE. This includes from high grade deposits that contain REE-bearing minerals such as monazite, xenotime and bastnäsite.

But the next step is to deepen our understanding of the formation, mineralogy and processing routes for lower grade deposits—particularly clay-hosted REE.

"We've got a lot of what are often considered 'primary' sources in Australia—that is, well-recognized rare earth minerals, at relatively high grade," Chris says.

"Mount Weld is one of the richest sources of rare earths in the world with grades of several percent rare earths. But the distribution of the rare earths is skewed towards the lighter end, which is quite common. There's another emerging style of deposit though, which is clay hosted."

According to Chris, when you analyze a clay earth deposit, the total rare earths is often much lower than you'd find somewhere like Mount Weld. However, the amount of heavy—the less abundant and more valuable—REE can be comparable to a traditional deposit. That means they could have an important role to play in providing a resilient and sustainable supply chain of heavy REE, despite the low total rare earth grade.

To gain insights into the geological processes and conditions that form clay-hosted REE deposits, we are applying expertise in regolith geoscience, geophysics, and remote sensing. This will enable us to produce deposit-scale case studies across various landscape environments where clay-hosted REE prospects occur.

Samples from these case studies are being analyzed. Researchers are using cutting edge characterization facilities to understand variability in mineralogy which ultimately controls mineral processing. Results will be incorporated into mineral system models for clay-hosted REE. These models are being developed by hub partner Geoscience Australia as part of their review of Australia's priority REE mineral deposit styles.

Dr. Rachael Morgan is Geoscience Australia's Critical Mineral Research and Development Hub Lead. She explains that a mineral system is defined as all geological factors that control the generation and preservation of mineral deposits.

"A mineral system model quantifies the controls on deposit formation by identifying factors such as fluid, structures, and changes in source and host rock chemistry, in order to develop an understanding of how a particular deposit may have formed," she says.

Using the knowledge gained from developing the mineral system model, researchers can identify relevant national datasets. These datasets can then be used as proxies to map the controls on deposit formation.

"These dataset layers are combined to produce a national mineral potential map that indicates the regions of Australia that are most prospective for clay-hosted REE deposits, and these maps can be used by industry to identify priority areas for exploration."

"The project will expand our geological understanding of Australia's potential to host deposits of this style," says Geoscience Australia's project lead Dr. Jessica Walsh.

"This will support new exploration and discovery in Australia for clay-hosted REE deposits and should ultimately lead to increasing Australia's inventory of REE, heavy-REE in particular. Collaborating on understanding how these deposits are formed also highlights where there are gaps in knowledge and data, which can then lead to further research."

Unlocking the potential of lower grade deposits

The collaborative research with Geoscience Australia that will lead to a better understanding of deposit characterization. We are also partnering with ANSTO on research that will accelerate the discovery and recovery from such deposits. That work will include the development of a pilot plant at ANSTO.

Dr. James Quinn, Senior Hydrometallurgist, ANSTO Minerals, points out that traditional 'ionic clay' deposits have been previously exploited overseas.

"The REE contained within such deposits are relatively easy to extract as opposed to 'clay-hosted' deposits where REE require harsher processing conditions to extract them and realize the value within.

"We have a lot of this style of 'clay-hosted' deposit within Australia, but there is a bit of uncertainty around how to process them efficiently, economically and in the most environmentally sustainable way. Also, ensuring that the intermediate REE-containing concentrates produced from them are compatible with existing downstream processing facilities is a key point."

In addition to developing a pilot plant that will allow Australian developers to test their ores at a relatively large scale, ANSTO is also developing processing flowsheets specifically for Australian clay-hosted deposits and the intermediate REE-containing concentrates they are likely to produce. That will ensure they perform well economically and environmentally and are tailored to Australian regulations, which are usually stricter than you would see elsewhere.

Downstream value chain

Another focus of the Australian Critical Minerals Research and Development Hub is research that will extend Australian value chains for REE. In particular, the project aims to produce rare earth material for magnet-making industries. This is an exciting opportunity to leverage Australia's resource potential to support onshore processing and create opportunities in downstream high value industries.

"Traditionally, Australia has been an exporter of raw materials rather than a processor. With rare earths, it can be challenging to make a high-grade oxide material because there's no domestic market for that. There's no one who can use it," Chris says.

One of the key aims of the project is to create the processes and the intellectual property around turning those materials into metals here in Australia.

"Once you've gone to metals, you've skipped a lot of the supply chain that you don't understand," he says.

"It doesn't have to be about making magnets or electric vehicles domestically. It's just about getting to the point where we can separate them, then turn them into metals, and then suddenly you have a product that is immediately marketable to Europe or the U.S. That helps the international supply chain look a little less bottlenecked and a little more certain."

Collaboration for national benefit

While several major companies in Australia are well established in conventional REE extraction and mineral concentrate production, the emerging industry around clay-hosted deposits presents opportunities for more companies. This could lead to an increased number of businesses mining and extracting REE in Australia.

According to Dr. Chris Griffith, Principal Consultant at ANSTO Minerals, supporting these companies to meet the growing demand for REE and other critical minerals demonstrates the value of critical minerals processing expertise already present within Australia's government science agencies.

"The Australian Critical Minerals Research and Development Hub is about getting the most out of the expertise that exists across our science agencies and bringing that together for the benefit of Australian industry," he says.

"We have such an abundance of resources here; it makes sense to try and bring as much of the processing back onshore as we can—adding value to what we have and diversifying global supply chains. That's what the Hub is trying to facilitate."

Provided by CSIRO