Interesting paper about mineral extraction from sea water: https://pubs.rsc.org/en/content/articlehtml/2017/ew/c6ew00268d https://pubs.rsc.org/en/content/artic

Interesting paper about mineral extraction from sea water: https://pubs.rsc.org/en/content/articlehtml/2017/ew/c6ew00268d https://pubs.rsc.org/en/content/articlehtml/2017/ew/c6ew0026... One thing is that as one extracts other minerals from the salt, the concentration of what remains increases, providing that the processed material isn't polluted with other chemicals used to separate the first pass extractions.