Lithium - what % is important, page-3

For processing of spodumene to lithium carbonate, the mica content is mostly irrelevant. Mica's have lower lithium contents, so they can drop the concentrate grade, however mica can be processed through the spodumene process. So mica content of spodumene for lithium carbonate production only increases the shipping cost. There is probably a reagent expense associated with additional mica, but there are byproducts with it too.

If you're selling the spodumene concentrate for other uses there might be other issues.