In short time, a geothermal power plant in California will produce more than just electric energy, because Lithium could be extracted from its hot waste water. The new technique developed by California-based Simbol Mining could make geothermal wells even more valuable. Extracting lithium with old technologies has up to now been considered impractical.
According to the researchers, the global lithium consumption is expected to increase threefold by 2020 as electric vehicles and energy storage in the electrical grid become more common. Lithium requires a lot of water and is usually extracted from soil. The geothermal waters at the Salton Sea, about 250 km inland and on top of the active San Andreas fault, are considered just as lithium-rich as the most productive brine lakes in Chile and Bolivia.
All previous attempts to pull lithium from this mineral-rich water were scuppered because it contains high levels of silicates, which clog equipment. The new process, licensed from the Lawrence Livermore National Laboratory in California, can be used to precipitate out the silicates, so they can be filtered out of the water.
The remaining water then flows over a chemical resin that pulls lithium ions from the salty solution and into a compound of lithium chloride, before the lithium-depleted water is returned to the ground. However, the company is now building its first demonstration plant, being able to generate about 1 ton of lithium metal a month.