Lithium is a vital component of “next generation” batteries that will power electric vehicles and provide storage for renewable power. As a result, global demand for the metal –dubbed ‘white petroleum’ due to its silver-white sheen - is forecast to grow by around 400% by 2025. In short, it has now become vital for technologies that enable a rapid transition towards low carbon economies.
This latest research project focussed on developing new and innovative satellite-based techniques that have the potential to substantially reduce the cost of lithium exploration. Such remote sensing techniques can also reduce the environmental impact of exploration by enabling better targeting of prospective areas for mining.
Experts from eleven organisations were involved in the study that centred on two areas of Cornwall.The approach was to develop combinations of EO techniques which, when used together, could identify target sites for further work within the selected areas.
Looking for change
As well as using other techniques such as heat mapping, the team looked for potential indicators of lithium in vegetation cover by investigating its impact on plants. Anomalies related to vegetation parameters such as health and temperature were correlated with rock alteration and the presence of geological faults. Using such techniques, the team was better able to predict areas that could host lithium bearing brines below the surface and, thereby, create a prospectivity map.
The team used data at different resolutions from Landsat, Sentinel-1 and 2, WorldView-3, GeoEye-1, ASTER, ALOS-1 and TerraSAR-X satellites, along with ground survey data from the British Geological Survey, as well as radiometric and magnetics data.
Using the same data sets, the team has also developed a digital environmental baseline map to show priority habitats, flood risk areas and urban settlements to act as an environmental monitoring tool. The average cost of environmental monitoring and compliance with environmental regulations for a mining operation is estimated to be around 5% of total project costs1.The tool developed by the team could provide the independent data required for compliance and monitor any changes in a cost-effective way.
Dr Cristian Rossi, Principal Earth Observation Specialist, Satellite Applications Catapult, who led the study said: “We are very excited by the findings of this project. This approach to lithium exploration which includes the estimation of multiple surface indicators has not been attempted before and may be highly applicable across the wider mining industry.
“We have shown that by combining a range of satellite data and expertise in UK mining, geology and Earth Observation, we can accurately map the environmental baseline and also delineate areas where lithium is more likely to be present at depth.
“These are the first digital maps that display potential lithium hotspots for initial investigation and validation. We are now looking at how we can improve this new tool which is attracting international interest from major lithium producers worldwide.”
Project partner Cornish Lithium Ltd will be working with the team to build on this initial research to help reduce the cost of exploration in the region.
Jeremy Wrathall, Founder & CEO, Cornish Lithium Ltd, said: “Cornish Lithium is delighted to have been involved in this ground-breaking work. The results of the study, and our collaboration with other project partners, has enabled us to significantly advance our exploration programme and better prioritise areas on which to focus our exploration for lithium-bearing brines in Cornwall.”
Probing beneath the surface
The team is now exploring options for the next phase to improve its understanding of the sub-surface environment. Such knowledge is considered vital if the UK is to develop a domestic source of lithium.
The project was funded through a grant of £850k from Innovate UK and the team, led by the Satellite Applications Catapult, included the British Geological Survey, the Camborne School of Mines (part of the University of Exeter), Carrak Consulting, Cornish Lithium Ltd, North Coast Consulting, CGG, Terrabotics, Telespazio Vega UK, Geo Performa and Dares Technology.
1 SNL Metals and Mining, 2015; “Permitting, Economic Value and Mining in the United States”