Comment by kragen

5 months ago

Hmm, I thought the Australian deposits were mostly spodumene. I appreciate the correction, although it's embarrassing; I'd rather be embarrassed than wrong.

2 comments

kragen

nandomrumber 5 months ago

At the mine's current size, it can fulfil a third of the worldwide demand for lithium spodumene concentrate,[1] which is used to produce lithium hydroxide, a component of lithium-ion batteries.

https://en.wikipedia.org/wiki/Greenbushes_mine

kragen 5 months ago
Further down on the page, it says:
> The mine sets a chemical-grade specifications benchmark of 6.0% Li2O minimum and 0.8% Fe2O3 maximum.
Spodumene is 0% iron. How much lithium does it contain on a Li2O basis? 8%, I think:
You have: lithium + aluminum + 2(silicon + 3 oxygen) You want: Definition: 186.089 You have: (2 lithium + oxygen) / 2 _ You want: % * 8.0282762 / 0.12455974
That suggests that the rock (pegmatite?) being mined there is about 75% spodumene. Is it possible that this is a misinterpretation, perhaps describing a standard for the output of the froth flotation process or similar, and the rock being dug up really is just a few percent spodumene?
No, as it turns out. The paper linked just before that says that none of the rock is quite that lithium-rich https://pubs.geoscienceworld.org/segweb/economicgeology/arti...:
> The lithium ore zones comprise mainly spodumene, apatite, and quartz, with some ore zones returning upward of 5 percent Li2O.
OTOH, that paper is from 01995, so maybe there are new findings since 30 years ago. It says the reserves there were 4% Li2O. Later in the paper, it explains:
> The hanging-wall lithium zone in the main pegmatite is generally richer (up to 5% Li2O, equivalent to 60–80% spodumene) than the footwall lithium zone
That seems to contradict adrian_b's strong statement:
> Spodumene is dispersed among other minerals into rocks and it only forms a few percent at most of those rocks, if not only fractions of a percent.
It could still be true at other mines.