Extracting strategic minerals for green economy from geothermal energy plants

US-based Simbol Materials started building a facility for the extraction of lithium, zinc and manganese from fluids used for electricity generation in geothermal plants. These three minerals are essential for the energy industry of the future. Specially lithium, a mineral with a high electric-chemical potential that is increasingly used to manufacture high-efficiency accumulators (lithium-ion batteries for electric vehicles) and electronic equipment.

The high-temperature underground fluids that are used in geothermal plants are commonly associated with several mineral-solutions. Simbol Materials verified that the Salton Sea aquifers in California, (a site where 5 geothermal plants are online with a total capacity of 170 MW) actually contain dozens of minerals, including lithium, zinc and manganese. There is such a concentration of such minerals that the latter can be extracted at cost-effective conditions.

Lithium is already produced from water solutions, but this method takes months, since after fluids are pumped into a basin the water takes time to evaporate, leaving salty elements on the ground. The novelty of this project consists in the use of geothermal fluids, that could form a sort of “mine”, already available and tested, producing significant benefits in economic and environmental terms. Furthermore, the system used for lithium extraction allows a huge time reduction for processing it. Indeed, Simbol Materials has developed a method that can filter about 20,000 litres of liquid in a few minutes, producing between 40 and 80 litres of a mixed salty solution. When completed, the new plant will produce about 500 tons of lithium carbonate per year.