Characterisation of Hyperaccumulators for Lithium Recovery from Ancient Mine Soils

The importance of lithium in modern industry is proven by a staggering triplication of the market for Li-based batteries, valued at $30b in 2017 and expected to reach $100b by 2025. Lithium is used as nanoparticles, particularly for batteries and electronics applications. Presently, lithium nanoparticles are manufactured using induction thermal plasma and other energy-demanding technologies. Furthermore, lithium is mined using significant volumes of water in areas such as South America, where aquifers are facing an ever-growing pollution from over-mining and agriculture, affecting the provision of clean and safe drinking water. We propose a switch in mining and manufacturing methods through the use of phytomining in ancient mine locations, to foster economic sustainability in areas affected by unemployment while maintaining the historic splendour of these sites. This paper will focus on the report of preliminary experiments using Agrostis Tenuis as hyperaccumulator for lithium and the characterisation of the biomass to assess its metal collecting behaviour. Our experiments have proven that in such areas, the amount of lithium (~1000 ppm) present in the sludges derived from mine adits can be recovered by autochthonous grasses (~20% per harvest) and transformed into re-usable nanoparticles using low-energy bio-synthesis.