Do you want salt with that?

The question came up when I was talking to the guy who drives trucks from Spain to Doha, carrying cables, then sells the trucks locally before flying home. Normally, long distance truckers might expect to carry a different load on the return leg, but not from Doha, where nothing is manufactured. On the other hand, they do need a lot of trucks for the construction projects, so it makes sense. But is it true that Qatar manufactures nothing? The huge desalination plants must produce a lot more salt than can be used domestically, so where does it go? Surely not back into the sea? It takes a shed load of energy to desalinate seawater, so it doesn't make sense to think of the salt as a mere byproduct. Maybe someone in the know can enlighten me - exactly what does happen to all that salt? I could read up about desalination of course, but it's far more fun just to wonder for a while.