‘Significant’ Lithium to be extracted in Cornwall
AMINING company has found “globally significant” deposits of valuable lithium in Cornwall and is preparing to start work on a £4 million pilot plant to extract the mineral.
Cornish Lithium Ltd, a mineral exploration company hunting for “battery metals” in the South West, said the results from preliminary sampling of lithium in deep geothermal waters at the United Downs Deep Geothermal Power Project at Gwennap, near Redruth, indicate some of the highest grades of lithium found anywhere in the world.
Geothermal waters which contain lithium are different from other occurrences in brine, given that the same water can be used to generate zerocarbon electrical power and heat. As such, these waters are rapidly becoming recognised as the ultimate ethical source of lithium, the company said.
Jeremy Wrathall, chief executive and founder of Cornish Lithium, said: “This is an exciting step towards the realisation of low-carbon lithium extraction from geothermal waters in Cornwall, and complements Cornish Lithium’s work to date on exploring for lithium contained within shallower geothermal waters in the county.
“The pilot lithium extraction plant, part-funded by the UK Government, that we will develop with Geothermal Engineering Ltd at the United Downs Deep Geothermal Power Project will allow us to evaluate green direct lithium extraction technologies which will bring us another step closer to commercial production of lithium in Cornwall,” he added.
“We now have increased confidence that these lithium-enriched geothermal waters can be found at depth across Cornwall and believe that there is significant potential to replicate combined lithium and geothermal extraction plants in different locations across the County where Cornish Lithium has mineral rights agreements in place”
The company, in collaboration with Geothermal Engineering Ltd (GEL), the developer of the United Downs Geothermal Power Project, was recently awarded funding from the Government’s Getting Building Fund to build a pilot lithium extraction plant at the United Downs site.
The £4 million project will design, procure and build a pilot plant to trial Direct Lithium Extraction (DLE) technology to extract lithium from the geothermal waters which circulate naturally at depth in the granite rock that underlies Cornwall.
The initial assay results show lithium concentrations of up to 260mg/L, which are believed to be amongst the highest published grades of lithium in geothermal waters globally.
Importantly, the Total Dissolved Solids (TDS) content of these Cornish waters is exceptionally low relative to other geothermal waters worldwide, making Cornish waters globally significant.
In particular, magnesium, a metal that makes processing more difficult and expensive, is extremely low.
Mr Wrathall added: “These results show that Cornish deep geothermal waters, unlike others around the world, have low salinity, meaning much lower concentrations of elements such as magnesium and sodium. When these elements are present in high concentrations it can make it difficult and more expensive to separate out the lithium compounds.
“Cornish geothermal waters should therefore be highly suitable for extraction methods using DLE technology.”