Just a thought that occured to me while sitting around. Well?
Possible but expensive
Salt dissolves in water. A centrifuge will not separate out something that is in solution.
Yep, your best bet is just to evaporate it and condense it.
If the centrifuge turns fast enough, then the concentration of salt can be increased on one side. It cannot become larger than the maximum concentration that can be dissolved at the temperature it is in; salt crystals will form in the water if you attempt to exceed that limit.
With an ultracentrifuge cascade you could separate salt water if there is a starting point of any difference in salinity.
But as I said it's not really practical compared to reverse osmosis.
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