o0Purple0o
I don’t think this information is public anywhere, but you could take a look into the 2023 Sustainability Report.
As you can see on Page 10 they’re looking for recycled metal for 2025 like Tin, aluminium, copper, steel, gold, cobalt and rare metals. On Page 12 you see the progress for each metal. Despite not mentioned from where they source their metals/minerals, this report might help you in your consideration.
Also more reports on https://nothing.tech/pages/sustainability