SUstainable MInerals for a resilient Transition to Net Zero (SUMIT 0)

It is increasingly evident that a net zero transition will be resource intensive. For example, per megawatt (MW) of installed capacity (electricity supply ~1000 homes), a single onshore wind turbine uses 3 tonnes (t) of copper (Cu), 0.75 t of manganese (Mn), 0.5 t of chromium (Cr) and nickel (Ni), 0.1 t of molybdenum (Mo) and smaller amounts of rare earth elements (REEs) (~15 kg). Solar photovoltaic (PV) devices have similar Cu requirements but offshore wind turbines use significantly more Cu (x2.5) and REEs (x10). Scaling up, ~140 Mt of critical metals will be utilised by renewable energy (wind/solar/geothermal) technologies and the energy storage devices required for a <1.5 degreeC climate change future. Thus there is growing concern about security of supply of critical elements.

In 2022, the UK government published its first Critical Minerals Strategy and will review the stability and security of critical mineral supply chains by the end of 2023. There has been much less consideration of the challenges we now face in protecting our soils and waters and indeed human health. Extraction of mineral resources is not only water intensive in areas that are already water-stressed but it inevitably generates waste materials. Past/current practices have already produced >280 gigatonnes (Gt) - this equates to a cube that is 6 km high! These are often uncurtailed and dispersal by wind and water results in contamination spread and expansive exposure for proximal populations. The contaminated dusts and waters contain a wide range of potentially toxic elements (PTEs), e.g. arsenic (As), lead (Pb), nickel (Ni), boron (B), molybdenum (Mo) which naturally co-occur within the mined materials. Individually, there are well-documented impacts upon human health, e.g. As is known to cause various cancers, Pb is known to affect brain development especially in children, but the cumulative effective of exposures to complex PTE mixtures is unknown.

The focus of this proposal is on copper (Cu) mining because (i) Cu is required across all low-carbon technologies; (ii) it is the gateway to co-occurring critical metals such as Mo, Re, Te, REEs; (iii) Cu mining wastes constitute almost half of all tailing wastes; (iv) these wastes contain the complex PTE mixtures that we need to study. Chile is by far the largest producer of Cu in the world and it also has more than 740 registered tailings areas, many of which are improperly managed and are impacting soil, water, food and human health, especially of indigenous communities. We therefore propose a new international partnership between the Sustainable Minerals Institute-International Centre of Excellence-Chile (SMI-ICE-Chile) and the University of Edinburgh (UoE) to bring together SMI-ICE-Chile's excellence in research, innovation and technological/capacity transfer in the mining industry of Chile and South America and Edinburgh's world-class research facilities and our complementary expertise.

Taking advantage of SMI-ICE-Chile's active projects, we will use a novel, holistic and integrated approach to address a key gap in understanding regarding PTE mixtures that will underpin assessments for ecological and human health risk as well as future work on sustainable waste treatment and critical metal recovery. By jointly engaging with the International Institute for Environmental Studies (IIES), we will enhance the long-term sustainability of our partnership and open up potential avenues for wider international collaboration and funding. In particular, we aim to facilitate discussions across the UK-Chile-Canada-Australia nexus which will be paramount to securing an environmentally sustainable supply of critical minerals in the future. By building on our experience of delivering scientific progress that also has positive socio-economic impact, we will also ensure a culturally aware provision of a better quality of life for indigenous communities.