[rockrr]

I wonder what they do with the salt and minerals that they extract from the water?

[BuffaloJack]

The salt and minerals will go back into the ocean. They don’t use stills much anymore; desalinization is done with polymer membranes. The membranes will allow pure water through and not the salt and dissolved stuff. You wind up with pure water on one side of the membrane and extra salty water on the other.