Researchers at Germany’s Karlsruhe Institute of Technology have developed an environmentally friendly process to extract lithium from the salty thermal water reservoirs that are located in the Upper Rhine Trench.
Similar to other initiatives that are taking place in the UK, the German scientists want to recover the white metal using minimally invasive processes.
The mechanism they have come up with consists of filtering out lithium ions from the thermal water and then further concentrating them until lithium can be precipitated as a salt.
“As far as we know, there can be up to 200 milligrams per litre,” said in a media statement Jens Grimmer, a geoscientist at KIT who co-developed the method with his colleague Florencia Saravia. “If we consistently use this potential, we could cover a considerable part of the demand in Germany.”
The mechanism consists of filtering out lithium ions from the thermal water and then further concentrating them until lithium can be precipitated as a salt
According to Grimmer, compared to traditional methods of lithium production from the South American salt flats and Australian solid rock, the KIT’s process doesn’t need external water inputs as the existing infrastructure of geothermal plants, through which up to two billion litres of thermal water flow every year, can be used.
At the same time, the new process generates hardly any overburden, the land consumption is minimal and since the thermal water is returned to the underground after use, no harmful substances are released and geothermal electricity and heat production are not impaired.
In terms of efficiency, the researcher said that the mechanism he is proposing allows for lithium to be continuously extracted within hours in the thermal water cycle of the geothermal plant, which greatly differs from how things are done at the Lithium Triangle’s deposits where the enrichment process takes several months and is highly weather-dependent.
Since the process can use the technical and energetic infrastructure of a geothermal plant, its CO2 balance also stands out when compared to traditional mining.
“We export many environmental problems to third countries in order to maintain and improve our living standards. With this process, we can assume our responsibility and extract important raw materials for modern technologies in an environmentally friendly way right on our own doorstep,” Florencia Saravia said in the brief. “We can also build up regional value chains, create jobs, and reduce geopolitical dependencies at the same time.”
Currently, Germany is a net importer of lithium from Chile, Argentina and Australia, as many companies use it for the production of battery cells for electric vehicles. Thus, the metal is considered of great importance for the climate protection program of the Federal Government.