The rare earth elements (REE), and in particular neodymium and dysprosium, are essential for renewable energy devices such as wind turbines and the development of electric motors for transport. At present the REE are sourced from either low concentration weathered granitoid (ion adsorption clay) deposits, or from high concentration carbonatite-related deposits, especially the World's dominant REE mine in hard-rock, altered carbonatite at Bayan Obo, China. The one major mine operator outside of China is the Mount Weld weathered carbonatite, Australia. Weathered carbonatites such as Mount Weld are some of the world's richest REE deposits and several are subject to active exploration. As part of the NERC Global Partnerships Seedcorn fund project WREED, we have carried out preliminary investigations of weathering products on carbonatite hosted REE deposits. Three end member weathering products have been identified (1) carbonate mineral dissolution leaves behind primary REE minerals, forming residual deposits; (2) dissolution and reprecipitation of REE phosphates and fluorcarbonate minerals results in the formation of new hydrated REE-phosphate or -carbonate minerals producing supergene enrichment; and (3) the formation of clay and iron-manganese oxide caps (either from weathering of the deposit itself, or from soil transport from surrounding rocks) that may hold the REE adsorbed to mineral surfaces (c.f. the ion adsorption deposits). High grade, weathered carbonatite deposits typically consist of a range of soil and weathered horizons, that may be phosphate-rich due to dissolution and re-precipitation of apatite and monazite during the weathering process (Mount Weld, Australia), overlain by later sediments that may be REE enriched either by accumulation of residual minerals in lake sediments (Tomtor, Russia). The mineralogy of the ore zone is linked to, but distinct from, the unweathered carbonatite rock, and includes phosphates, crandallite-group minerals, carbonates and fluorcarbonates and oxides. In this study we will utilise bulk rock geochemistry, sequential leaching techniques, mineral chemistry and microbiology to investigate the processes producing different weathered REE deposit styles in carbonatites and their influence on the economic REE grade and environmental impact of deposits. Bulk rock geochemistry will be used to quantify element enrichments and depletions relative to bedrock, and to investigate the potential for ion adsorption style mineralisation in weathered carbonatites. Mineral chemical techniques will be used to investigate the timing of weathering, host minerals of the REE, potential beneficial or harmful changes in chemistry relative to primary minerals, and proxies for the environmental controls on weathering style. These data will be combined with existing records of surface morphology and weathering depth to produce overall genetic models linking climate, geomorphology and geochemistry that will allow prediction of the resource potential of the carbonatite weathered zone. The results will be communicated with industry and the public to raise awareness of the resource requirements of decarbonisation, and potential routes to increased extraction efficiency and reduced impact.

Rare earth elements (REE) are the headline of the critical metals security of supply agenda. All the REE were defined as critical by the European Union in 2010, and in subsequent analysis in 2014. Similar projects in the UK and USA have highlighted 'heavy' REE (HREE - europium through to lutetium) as the metals most likely to be at risk of supply disruption and in short supply in the near future. The REE are ubiquitous within modern technologies, including computers and low energy lighting, energy storage devices, large wind turbines and smart materials, making their supply vital to UK society. The challenge is to develop new environmentally friendly and economically viable, neodymium (Nd) and HREE deposits so that use of REE in new and green technologies can continue to expand. The principal aims of this project are to understand the mobility and concentration of Nd and HREE in natural systems and to investigate new processes that will lower the environmental impact of REE extraction and recovery. By concentrating on the critical REE, the research will be wide ranging in the deposits and processing techniques considered. It gives NERC and the UK a world-leading research consortium on critical REE, concentrating on deposit types identified in the catalyst phase as most likely to have low environmental impact, and on research that bridges the two goals of the SoS programme. The project brings together two groups from the preceding catalyst projects (GEM-CRE, MM-FREE) to form a new interdisciplinary team, including the UK's leading experts in REE geology and metallurgy, together with materials science, high/low temperature fluid geochemistry, computational simulation/mineral physics, geomicrobiology and bioprocessing. The team brings substantial background IP and the key skills required. The research responds to the needs of industry partners and involves substantive international collaboration as well as a wider international and UK network across the REE value chain. The work programme has two strands. The first centres on conventional deposits, which comprise all of the REE mines outside China and the majority of active exploration and development projects. The aim is to make a step change in the understanding of the mobility of REE in these natural deposits via mineralogical analysis, experiments and computational simulation. Then, based on this research, the aim is to optimise the most relevant extraction methods. The second strand looks to the future to develop a sustainable new method of REE extraction. The focus will be the ion adsorption deposits, which could be exploited with the lowest environmental impact of any of the main ore types using a well-controlled in-situ leaching operation. Impact will be immediate through our industry partners engaged in REE exploration and development projects, who will gain improved deposit models and better and more efficient, and therefore more environmentally friendly, extraction techniques. There will be wider benefits for researchers in other international teams and companies as we publish our results. Security of REE supply is a major international issue and the challenges tackled in this research will be relevant to practically all REE deposits. Despite the UK not having world class REE deposits itself, the economy is reliant on REE (e.g. the functional materials and devices industry is worth ~£3 Bn p.a.) and therefore the UK must lead research into the extraction process. Manufacturers who use REE will also benefit from the research by receiving up to date information on prospects for future Nd and HREE supply. This will help plan their longer term product development, as well as shorter term purchasing strategy. Likewise, the results will be useful to inform national and European level policy and to interest, entertain and educate the wider community about the natural characters and importance of the REE.

Rare Earth Elements (REE) are used in many low carbon technologies, ranging from low energy lighting to permanent magnets in large wind turbines and hybrid cars. They are almost ubiquitous: in every smartphone and computer. Yet 97% of World supply comes from a few localities in China. Rare earth prices are volatile and subject to political control, and but substitute materials are difficult to design. The most problematic REEs to source are neodymium and the higher atomic number 'heavy' rare earths - a group dubbed the 'critical rare earths'. However, with many potential rare earth ore deposits in a wide variety of rocks, there is no underlying reason why rare earths should not be readily and relatively cheaply available. The challenge is to find and extract rare earths from the right locations in the most environmentally friendly, cost efficient manner to give a secure, reasonably priced, responsibly sourced supply. In this project, the UK's geological research experts in rare earth ore deposits team up with leaders in (a) geological fluid compositions and modelling, (b) using fundamental physics and chemistry of minerals to model processes from first principles and (c) materials engineering expertise in extractive metallurgy. This community brings expertise in carbonatites and alkaline rocks, some of the Earth's most extreme rock compositions, which comprise the majority of active exploration projects. The UK has a wealth of experience of study of economic deposits of rare earths (including the World's largest deposit at Bayan Obo in China) which will be harnessed. The team identify that a key issue is to understand the conditions that concentrate heavy rare earths but create deposits free from thorium and uranium that create radioactive tailings. Results so far from alkaline rocks and carbonatites are contradictory. A workshop will bring together the project team and partners, including a leading Canadian researcher on rare earth mobility, to debate the results and design experiments and modelling that can be done in the UK to solve this problem. Understanding, and then emulating how REE deposits form, may provide us with the best clues to extract REEs from their ores. One important route is to understand the clay-rich deposits in China which provide most of the World's heavy rare earths; they are simple to mine, not radioactive, and need little energy to process. The workshop will consider how these deposits form, how we can use our experimental and modelling expertise to understand them better and predict where companies should explore for them. The other main problem, restricting development of almost all rare earth projects, is the difficulty of efficient separation of rare earth ore minerals from each other and then extraction of the elements from those ores. A work shop on geometallurgy (linking geology through mining, processing, extractive metallurgy and behaviour in the environment) will be used to explore how geological knowledge can be used (a) to predict the processing and environmental characteristics of different types of ores and (b) to see if any new potential processing methods might be tried, taking advantage of fundamental mineralogical properties. The two workshops link geology to metallurgy, using one to inform the other. This project will form the basis for an international collaborative consortium bid to NERC. It will also catalyse a long-term UK multidisciplinary network linking rare earth researchers to users, and promote the profile of the UK in this world-wide important field. Before the team design the research programme, they will consult academic colleagues working on new applications of rare earths and rare earth recycling, plus exploration companies, users further along the up the supply chain and policy makers. This will ensure that the proposals developed have maximum impact on future supply chain security.

The Circular Economy (CE) is a revolutionary alternative to a traditional linear, make-use-dispose economy. It is based on the central principle of maintaining continuous flows of resources at their highest value for the longest period and then recovering, cascading and regenerating products and materials at the end of each life cycle. Metals are ideal flows for a circular economy. With careful stewardship and good technology, metals mined from the Earth can be reused indefinitely. Technology metals (techmetals) are an essential, distinct, subset of specialist metals. Although they are used in much smaller quantities than industrial metals such as iron and aluminium, each techmetal has its own specific and special properties that give it essential functions in devices ranging from smart phones, batteries, wind turbines and solar cells to electric vehicles. Techmetals are thus essential enablers of a future circular, low carbon economy and demand for many is increasing rapidly. E.g., to meet the UK's 2050 ambition for offshore wind turbines will require 10 years' worth of global neodymium production. To replace all UK-based vehicles with electric vehicles would require 200% of cobalt and 75% of lithium currently produced globally each year. The UK is 100% reliant on imports of techmetals including from countries that represent geopolitical risks. Some techmetals are therefore called Critical Raw Materials (high economic importance and high risk of supply disruption). Only four of the 27 raw materials considered critical by the EU have an end-of-life recycling input rate higher than 10%. Our UKRI TechMet CE Centre brings together for the first time world-leading researchers to maximise opportunities around the provision of techmetals from primary and secondary sources, and lead materials stewardship, creating a National Techmetals Circular Economy Roadmap to accelerate us towards a circular economy. This will help the UK meet its Industrial Strategy Clean Growth agenda and its ambitious UK 2050 climate change targets with secure and environmentally-acceptable supplies of techmetals. There are many challenges to a future techmetal circular economy. With growing demand, new mining is needed and we must keep the environmental footprint of this primary production as low as possible. Materials stewardship of techmetals is difficult because their fate is often difficult to track. Most arrive in the UK 'hidden' in complex products from which they are difficult to recover. Collection is inefficient, consumers may not feel incentivised to recycle, and policy and legislative initiatives such as Extended Producer Responsibility focus on large volume metals rather than small quantity techmetals. There is a lack of end-to-end visibility and connection between different parts of techmetal value chains. The TechMet consortium brings together the Universities of Exeter, Birmingham, Leicester, Manchester and the British Geological Survey who are already working on how to improve the raw materials cycle, manufacture goods to be re-used and recycled, recycle complex goods such as batteries and use and re-use equipment for as long as possible before it needs recycling. One of our first tasks is to track the current flows of techmetals through the UK economy, which although fundamental, is poorly known. The Centre will conduct new interdisciplinary research on interventions to improve each stage in the cycle and join up the value chain - raw materials can be newly mined and recycled, and manufacturing technology can be linked directly to re-use and recycling. The environmental footprint of our techmetals will be evaluated. Business, regulatory and social experts will recommend how the UK can best put all these stages together to make a new techmetals circular economy and produce a strategy for its implementation.