The long-held notion that precious metals, minerals, and other useful substances can be extracted from natural waters is starting to become realized at several locations of geothermal brines. In a recent study by A. Maimoni of the Lawrence Livermore National Laboratory it was determined that there is a high potential for minerals recovery from the hot brines of a 1000-MWe geothermal power station at the Salton Sea geothermal field in southern California. The study estimated that the revenue from the minerals could substantially exceed that from the power station (Geothermics, 11, 239–258, 1982).
According to the study, ‘A 1000-MWe power plant could recover 14–31% of the U.S. demand for manganese.’ In the example of lithium production, such a geothermal plant could produce 5–10 times the annual world output of lithium. Large quantities of lead and zinc could be extracted, as well as significant amounts of gold, platinum, and silver. The chemical composition of the brines is incredibly complex, however, for reasons not currently understood.