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USGS uses machine learning to show large lithium potential in Arkansas

(www.usgs.gov)
280 points antidnan | 3 comments | 22 Oct 24 17:05 UTC | HN request time: 0s | source
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_heimdall ◴[22 Oct 24 22:34 UTC] No.41919400[source]▶
Well I guess this is a good win for short term energy infrastructure, though I'm always pretty torn when its at the cost of ripping open huge swaths of earth to get at the raw material.

It is interesting to see how much of this data could be modelled based on wastewater brines from other industries in the area, assuming we go on to mine the lithium it will say a lot if the ML predictions prove accurate.

One thing I couldn't tell, and its probably just a limitation of how much time I could spend reading the source paper, is what method would be needed to extract the bulk of the lithium expected to be there. If processing brine water is sufficient that may be easier to control externalities than if they have to strip mine and get all the overburden out of the way first.

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jofer ◴[22 Oct 24 22:59 UTC] No.41919627[source]▶
You physically can't remove the overburden for this. The Smackover is at a depth of multiple kilometers in most of these areas.

It's mining brine. I.e. the "mines" are basically deep water wells.

The limestone itself doesn't have any lithium. It's the water in the pores in the limestone that is relatively concentrated in lithium.

In most of these cases, you're already producing brines from the smackover formation as a part of existing oil and gas production, but the brine is being re-injecting after oil is separated from it. The idea is that it's better to keep those and evaporate them down for lithium production.

That does require large evaporation ponds, generally speaking, but it's not strip mining.

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1. pfdietz ◴[23 Oct 24 00:59 UTC] No.41920483[source]▶
I think they're using better processes than evaporation these days. For example, concentrating the brine using reverse osmosis first.
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2. jofer ◴[23 Oct 24 01:36 UTC] No.41920777[source]▶
Those are expensive and are avoided when possible. Brine ponds are cheap if you can use them. But with that said, yeah, evaporation ponds don't work especially well on the Gulf Coast.
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3. pfdietz ◴[23 Oct 24 02:35 UTC] No.41921193[source]▶
The process for here, I was reading, would involve concentration of the lithium with resin absorbers (to separate it from other alkali elements, I imagine), followed by elution into water, reverse osmosis, and only then evaporation. This is called "DLE": Direct Lithium Extraction.