system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: harvesting salt from sea water

I've just an ace doc on Smithsonian channel, and they explained how it is dried in different pools and harvested when dry, but then mentioned "it is then washed before shipping". So question is: how can you wash something that is soluble?  The dirt will still be there when the water is evaporated away..
gpt
The amount of salt you can dissolve in water is finite.  Once you've dissolved that much, you can't dissolve any more.  So you can wash salt in that brine (it's saltier than sea water, so salt water might be confusing).  Dirt and sand still wash off.