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Comment by alex_young | Hacker News Reader

  Lithium extraction is also environmentally damaging, whether from the … brine extraction that pumps massive amounts of water to the surface to dry.

That’s a bit of a stretch. Pumping water to the surface of a dry lakebed far from most life and letting it evaporate is pretty low on the environmental impact scale from mining. I wonder how that compares to sodium extraction.

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I thought the issue with evaporative brine projects was mainly the water use in generally water scarce areas. There are direct extraction technologies that are better. Sodium you can just let the ocean evaporate in ponds, although this destroys wetlands (see for example a bunch of these around the SF Bay, some being restored to their native state).

With lithium they are pumping deep water up to the surface, not adding any. The water holds the lithium and is part of a massive ancient aquifer.

Lithium is also extracted via ocean water evaporated in ponds. You do need a bed with a high concentrated amount of lithium near the ocean, those are not uncommon.

Of course doing that you get far far more sodium .....

Right, I recall a question of native populations with limited access to water and then water shows up suddenly but for extracting the lithium.

Hmm, i assume desalination could get the sodium out and also give us fresh water, maybe another incentive for desalination.

There are several issues with brine extraction, including intensive water usage, and atmospheric pollution (the extraction releases e.g. sulphur dioxide).

This is a good overview on some of the environmental impacts: 'Environmental impact of direct lithium extraction from brines' (2023) in Nature Reviews Earth & Environment, PDF: https://www.nature.com/articles/s43017-022-00387-5.pdf

I agree it’s a little overstated, but regardless, Sodium and Chromium are much simpler to use.

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