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Comment by laweijfmvo | Hacker News Reader

I'm assuming it's not a giant 15M ton chunk of (highly reactive) metal in the ground, but rather they took a bucket of dirt, analyzed it, and extrapolated how much lithium is available in the ground. My question is, how much "earth" do they need to dig up and refine to extract this amount of lithium?

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from what i can see the media/government minister have blown this out of proportion.

First off it looks like they identified 15M tonnes of lithium hosting rock (pegmatite) which has a grade of 0.4% of lithium in the form of spodumene (which then needs ot be processed to extract the lithium out of).

But in general, how it works is they drill a bunch of holes in the ground and analyse the cores. From that that interpolate the size/shape of the ore body and calculate an estimate of size.

The more holes they drill the greater the confidence.

There is a lot of 'art' to this science

Roughly what how much volume would 15m tons of pegmatite take up? I have no intuitive sense of scale with these things.

Rocks tend to be 5-10x denser than water, so assume 2 million cube meters. That is just 2 square kilometers 1 meter high, so not mountains or so. As a comparison, for a large iron mine they dig up many billions of tons of rock, and that is for very cheap iron, so you wouldn't need a very large operation to dig this up.

Useful tool to reason about this. Thanks!

curious how you know all this info, if you can share to the level you feel comfortable

this site says 0.4% so they would need to extract 3.5B tons of rock

https://thethaiger.com/news/national/thai-lithium-deposits-o...

Its not. Its 0.4% of the 15M Tonnes. (so much smaller)

This is most likely government minister/media hype.

double check your math

Normally an announcement like this would be based on a program of drilling. But yes there would be a lot of interpolation and I think some extrapolation.

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