Thank you very much for that explanation; I knew of the current procedure but not the process. There is, in my experience, a Very Big "But" in its entirety, alluded to your third paragraph's opening "If":
Effectively all waters but most especially brine waters contain any number of sulfates & sulfites - SO
4s & SO
3s, and carbonates and their ilk - CO
3s and so forth; attached to or otherwise associated with those anions are their balancing cations. Those last are the interesting fellas: usually metalliferous and apart from the nigh-ubiquitous calcium & sodium, whatever other metals present (Li+ among them) in the host rocks are dissolved in these hydrothermal solutions.
Now, the quintessentially ionic-bonded lithium ranks as possibly the element easiest to extract, but here come the Big But: under effectively all such hydrothermal situations, that nasty little ever-present calcium is about the worst. The reason is that in its most common form - calcium carbonate - it presents a negative dissolution gradient: whereas most compounds increase in solubility as temperatures rise, CaCO
3 decreases. So when, as in the above process, the fluids are brought to steam-creating temperatures,
poof! all those fancy turbines and associated pipes quickly (read: just about instantaneously) become clogged with limescale. This has been the bugaboo of the geothermal power industry for ever.
So I wish all who endeavor in the field well, and hope the calcium problem eventually is slain. The prospect held great appeal for me a few...years???
....
...
ago, and we thought we knew a lot then.