4 ms·

Seawater-> extract the lithium as a useful byproduct from desalination plants https://www.science.org/content/article/seawater-could-provide-nearly-unlimited-a

• londons_explore 5y ago
  Most desalination plants only concentrate the ocean salts a little. The more you concentrate them, the more energy you need to put in to get any more water out. I think the only time this would make economic sense is if there are laws in place saying brine may not be returned to the ocean (for environmental reasons). In that case, it would make sense to concentrate it further with reverse osmosis, and then use multi-stage flash to further concentrate the brine. After a few more steps, you could probably sell most of the resulting salts.
  • colechristensen 5y ago
    But if you’re already going to extract from seawater, you might as well take whatever head state you can get.
    • Consultant32452 5y ago
      What is the process by which drinking water is extracted from seawater, and does that give you any savings at all with regards to a goal of extracting minerals?
      • colechristensen 5y ago
        You either boil it or force it through a semi-permiable membrane. In both methods you get two products: one one side pure water, on the other water with a higher concentration of non-water things as waste, most often just dumped back into the ocean. That waste stream is just a bit closer to the end product than taking from the sea directly.
      • pfdietz 5y ago
        The most common approach is reverse osmosis. This yields a waste brine that is up to 2x as concentrated as seawater. That's not negligible: it would reduce the cost of Li extraction that is proportional to mass flow by a factor of 2.
  • HPsquared 5y ago
    If it's unlawful to discharge brine to the ocean (that is, concentrated seawater), it'd still probably be more economical to just dilute it before discharge (they probably already do this).
    • pinot 5y ago
      If you need a desal plant, probably not a lot of water laying around to dilute your brine stream
      • YokoZar 5y ago
        Are they allowed to dilute it with wastewater?
        • eutectic 5y ago
          Purifying wastewater is much cheaper than desalination.
      • HPsquared 5y ago
        Dilute it with seawater, I mean. Even it's not safe to discharge concentrated brine with, say, 10x the normal salt concentration, maybe seawater with 1.1x the usual concentration (or whatever it is) would be okay.
        • londons_explore 5y ago
          In some me places it is hard to discharge even 1.1x brine. In the future it might be necessary to concentrate it all the way to solid salt crystals and then truck them away.
          • iostream24 5y ago
            Salt is just a depleted battery from the future
    • deleted 5y ago