Published on September 24th, 2012 | by Nicholas Brown1
New California Law to Boost Sustainable Materials Industry
September 24th, 2012 by Nicholas Brown
Do you think it is possible to mine lithium and manganese without actually excavating it from the ground?
It is. And, unlike material mining in general, which technically causes destruction for every unit of minerals extracted, minerals such as lithium, manganese, and other minerals can be extracted from what is called geothermal brine.
California’s Gov. Jerry Brown has signed AB 2205 into law to pave the way for the geothermal brine mineral extraction industry. It is intended to bring extraction regulations “up to date.”
“AB2205 will accelerate the green economy in California,” said Senate Majority Leader Ellen Corbett. “Lithium and other critical materials found in the Salton Sea Geothermal Region are vital to electric vehicles, grid storage, and other clean energy technologies needed to meet the state’s climate targets.”
How Brine is Obtained from Underground, and How Geothermal Power Plants Work
Geothermal power plants utilize heat from under the earth’s surface (geothermal heat) to boil water and produce steam which is used to drive a steam turbine. They normally operate by pumping water into what is called a geothermal well, and the geothermal heat raises the water temperature, and the water exits the well, and enters the power plant.
At this stage, the water is now brine because it contains salts and minerals from the well, including the lithium and manganese I mentioned above.
The brine is under pressure, but, when it enters the steam power plant, it is allowed to rapidly expand (vapourize) into steam, which then rushes through steam turbine blades, forcing them to turn.
The salts I mentioned above are not necessarily sodium chloride (table salt), but brine can contain lithium salts (lithium chloride). Lithium chloride is a compound from which pure lithium can be extracted.
Elemental lithium is rare, so it is obtained from more abundant compounds, including lithium chloride, lithium carbonate, lithium hydroxide, and hectorite clay.