A shift from fossil fuels to low-CO2 technologies will lead to greater consumption of certain essential raw materials. Tellurium (Te) and selenium (Se) are 'E-tech' elements essential in photovoltaic (PV) solar panels. They are rare and mined only in small quantities; their location within the Earth is poorly known; recovering them is technically and economically challenging; and their recovery and recycling has significant environmental impacts. Yet demand is expected to surge and PV film production will consume most Se mined and outstrip Te supply by 2020. Presently, these elements are available only as by-products of Cu and Ni refining and their recovery from these ores is decreasing, leading to a supply risk that could hamper the roll-out of PV. Meeting future demand requires new approaches, including a change from by-production to targeted processing of Se and Te-rich ores. Our research aims to tackle the security of supply by understanding the processes that govern how and where these elements are concentrated in the Earth's crust; and by enabling their recovery with minimal environmental and economic cost. This will involve >20 industrial partners from explorers, producers, processors, end-users and academia, contributing over £0.5M. Focussed objectives across 6 environments will target key knowledge gaps. The magmatic environment: Develop methods for accurately measuring Se and Te in minerals and rocks - they typically occur in very low concentrations and research is hampered by the lack of reliable data. Experimentally determine how Te and Se distribute between sulfide liquids and magmas - needed to predict where they occur - and ground-truth these data using well-understood magmatic systems. Assess the recognised, but poorly understood, role of "alkaline" magmas in hydrothermal Te mineralisation. The hydrothermal environment: Measure preferences of Te and Se for different minerals to predict mineral hosts and design ore process strategies. Model water-rock reaction in "alkaline" magma-related hydrothermal systems to test whether the known association is controlled by water chemistry. The critical zone environment: Determine the chemical forms and distributions of Te and Se in the weathering environment to understand solubility, mobility and bioavailability. This in turn controls the geochemical halo for exploration and provides a natural analogue for microbiological extraction. The sedimentary environment: Identify the geological and microbiological controls on the occurrence, mobility and concentration of Se and Te in coal - a possible major repository of Se. Identify the geological and microbiological mechanisms of Se and Te concentration in oxidised and reduced sediments - and evaluate these mechanisms as potential industrial separation processes. Microbiological processing: Identify efficient Se- and Te-precipitating micro-organisms and optimise conditions for recovery from solution. Assess the potential to bio-recover Se and Te from ores and leachates and design a bioreactor. Ionic liquid processing: Assess the ability of ionic solvents to dissolve Se and Te ore minerals as a recovery method. Optimise ionic liquid processing and give a pilot-plant demonstration. This is the first holistic study of the Te and Se cycle through the Earth's crust, integrated with groundbreaking ore-processing research. Our results will be used by industry to: efficiently explore for new Te and Se deposits; adapt processing techniques to recover Te and Se from existing deposits; use new low-energy, low-environmental impact recovery technologies. Our results will be used by national agencies to improve estimates of future Te and Se supplies to end-users, who will benefit from increased confidence in security of supply, and to international government for planning future energy strategies. The public will benefit through unhindered development of sustainable environmental technologies to support a low-CO2 society.

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.