You'd also need to think up good uses for the sodium chloride or dump it somewhere. The sulfate, potassium and calcium would probably be useful if they could be easily separated but the sodium and chloride ions are by far the majority and are not going to be profitable in comparison to the current operations we use to obtain them.
> You'd also need to think up good uses for the sodium chloride or dump it somewhere.
Okay, so California ends its drought permanently and becomes a major supplier of magnesium and table salt.
Slightly-less-facetiously: sodium chloride has all sorts of industrial uses (on top of its culinary uses). The good uses are, in other words, already thought up in droves.
Further, most salt production already entails taking seawater and pulling out the water. Ain't too much of a stretch to, you know, actually keep the water instead of letting it evaporate into the atmosphere.