To tackle climate change, there is a move towards global decarbonisation that will lead to increased demand for a range of REE in the coming decades. As resources of primary REE are finite and global supply is highly dependent on China, adopting circular strategies including reuse and recycling may improve the security of supply of REE for countires like the UK, but also alleviate pressure on primary supply.

Products with embedded REE

Many REE (e.g. Nd, Dy, Pr, Tb) are used in the production of NdFeB magnets. Figure 7 shows the end-use share of NdFeB magnets. These NdFeB magnets embedded in REE-bearing products have different lifespans, ranging from 2 to 3 years in consumer electronics, 9 to 13 years in EVs, and 25 to 35 years in wind turbines. REE plays an important role in green and clean energy technologies, including wind turbines, electric vehicles, fuel cells, and lighting. EVs sales and wind turbine installations have been increasing in the UK during the past few years. Therefore, EVs and wind turbines have a high potential to be future secondary sources of supply of certain REE (Nd, Dy, Pr, Tb). The availability of secondary sources of REE depends on several factors, including historical production, product lifespan, collection rates and the yields of recycling. When REE-bearing products enter the end-of-life stage, there are many opportunities to retain the highest value REE within the UK economy.

Current situation and challenges

Potential secondary sources of REE include industry by-products, wastewater and end-of-life products. Among them, the EoL products have the greatest potential for secondary supply. Since the mid-1980s, NdFeB magnets have been manufactured, and widely used, such as in hard disk drives and electric motors. Considering product lifespan, there are already opportunities to recycle the REE within NdFeB magnets as a secondary supply. However, only 1% of REEs are recovered, and less than 1% of NdFeB magnets are recycled. The main destinations of REE-bearing waste include exports to other countries, landfilling and losses as contaminants in various waste streams (Figure 2). REE are technically and economically difficult to be collected and recycled because of the small quantities of REE in many applications, the complexity of products, lack of support for developing novel segregation and scaling up the recycling processes. In the future, there are opportunities to recycle REE from EVs and wind turbines. Therefore, it is important to monitor REE flows across the lifecycle stages at different levels (i.e. substances, components, products), as well as develop end-of-life management to imporve circularity of REE supply.

In the near future, there will be rapidly growing REE demand. In the short term, secondary REE are unlikely to overtake primary supply. In the long term, developing recycling technologies and infrastructure could contribute to tackling the criticality of REE. The stock modelling can show the potential quantities available for recycling and highlight the need for future recycling capacity.

Recycling technologies and circular strategies

REE are considered as critical mineral resources, therefore, several government interventions are needed to support both the primary and secondary supply of REE. In terms of secondary sources, financial investment is needed in research and development (research and development) focused on resource efficiency, separation and recycling technologies, as well as infrastructure for the collection and recycling of REE-bearing products.

Collaboration, both globally and domestically, is key to creating a diverse primary and secondary REE market and resilience of both primary and secondary supply. For example, the Rare Earth Industry Association (REIA) and the European Raw Materials Alliance (ERMA) gather togther REE stakeholders to exchange data, information and knowledge related to REE. Traceability is particularly significant for creating a circular economy system of REE. It is important for governments, academia and industry stakeholders across the REE value chain to collaborate in developing a circular economy system and improve the traceability and transparency of REE.

Education includes training the next-generation of skilled workers across the REE value chain, with a focus on the circular economy, while educational campaigns for consumers can improve understanding of the social and environmental impacts of the REE. Education has the potential to drive social behaviour change to circular use and recycling of REE-bearing products, especially for consumer electronics and electric mobility.

Regulatory intervention can be more powerful in supporting the secondary supply of REE. The extended producer responsibility (EPR) scheme can enhance not only the producers' responsibility for EoL product management, but also the product design for disassembly, reuse, repair and recycling. Further regulatory issues such as taxes, international trade laws, standardisation, investment and environmental regulations are discussed on the legal and regulatory webpage.

Background geological information and challenges

In the UK there are many documented occurrences of REE-bearing minerals, which include: monazite, allanite fergusonite, chevkinite, gadolinite and synchysite. However, in most cases these occurrences comprise only minor low tenor REE enrichment over restricted areas. For example, many of these minerals are found as rare accessory phases in some Tertiary granites, or are minor accessories to lead-zinc-fluorite mineralisation in the Northern Pennine Orefield (Walters and Lusty, 2011). To date there has been no mine production of REE-bearing minerals in the UK, nor are there any deposits in which REE reserves or resources have been reported. To date there has only been very limited evaluation of the REE potential in the UK. During the early 1990s BGS made a preliminary assessment of the REE contents of three late Caledonian alkaline intrusive complexes in north-west Scotland. Rock and drainage samples from Loch Borralan, Loch Ailsh and Loch Loyal were analysed for Ce, La and Y (Shaw and Gunn, 1993). During this period BGS undertook an assessment of the economic potential of mudstone-hosted nodular monazite in south-central Wales (Smith et al., 1994). More recently a BGS-hosted MSc student reappraised drill core from the ultramafic section of the Loch Borralan Complex to further assess its potential as a REE resource (Griffith, 2011). In 2013 BGS studied the formation of late-stage allanite-bearing veins associated with the Loch Loyal Syenite Complex (Hughes et al., 2013; Walters et al., 2013).

Even though REE minerals are known to occur in the UK, many of them are quite rare and are typically found in minor amounts in a few localities. It is worth noting that REE have never been commercially extracted in the UK, nor has there been any systematic exploration for REE.

A priority target for further investigation is the Cnoc nan Cuilean Intrusion in north-west Scotland. The hydrothermal, allanite-bearing veins that crosscut the intrusion contain the highest REE grades recorded in the UK (up to 2 wt. % TREO) (Walters et al., 2013). The known occurrence of significant hydrothermal, REE-mineralised veins associated with alkaline igneous rocks elsewhere in the world provides a strong basis for evaluating this area further. However, there is currently no commercial process for extracting REE from allanite; this coupled with the thin and discontinuous nature of the veins, makes them unlikely to be economic.

It is also important to note that previous work by BGS on the Caledonian alkaline intrusions of northwest Scotland has focussed on the PGM potential 6 of selected parts of these bodies. Systematic investigations over the entirety of these complex intrusions are recommended in order to fully evaluate their REE potential.

UK critical minerals strategy and market opportunities

A recent UK criticality assessment published by BGS, commissioned by BEIS, shows REE high on the list. The security of a rare-earth material supply is crucial to the UK's electrification ambitions which are required to meet the UK government's net zero target. The UK's Critical Minerals Strategy announced in 2022 aims to accelerate the growth of the UK's domestic capabilities; collaborate with international partners; and enhance international markets to make them more responsive, transparent and responsible. There are significant opportunities for the UK to deploy its expertise and forefront research assets for innovation in these areas and establish REE market share.

To build up the sustainable supply chain of REE in the UK, the UK would require diversifying the supply of REE, and exploring the possibility of mining and refining ores into metals and alloys. The UK has a leading role in research and development and education of metal refining and green chemistry. Therefore, it is important to use UK strength to develop new innovations for the chemical treatment and separation of REEs. Furthermore, there are many UK-based original equipment manufacturers (OEMs). Thus, it is also suggested to provide incentives for OEMs to develop magnet production and its end-of-life management.

Recycling of REE-containing magnets and products for secondary supply

The UK will need to secure significant quantities of REE to achieve the electrification transition. There are supply risks and limits for domestic primary production. Hence, in the long term, it is crucial to develop an ecosystem for secondary supply. The current in-use stocks could provide buffer capacity if circular economy systems are established. In the future, assuming that the net-zero targets materialise, the UK stock in products could create viable circular economy business opportunities. As most of the current plants are still at the pilot scale, it is necessary to assess the technology readiness levels (TRLs) of the existing REE recovering technologies in the UK. The UK has expertise and capability in material science and REE recycling. For example, the University of Birmingham has strong research expertise in recovering REE. Investing in research and development and establishing a secondary supply chain could expand the recycling capacity of REE and stimulate further innovation in magnets, especially research into next-generation magnet materials.