When that one mine runs out of salt? It will be closed. We as a humanity will not run out of salt, some places have the opposite problem: https://en.wikipedia.org/wiki/Monte_Kali
"According to the Werra Potash Mining Museum in Heringen, Monte Kali has been in operation since 1976; as of August 2016, it covered 98 hectares (240 acres) and contained approximately 201 million tonnes of salt, with another 900 tonnes being added every hour and 7.2 million tonnes a year."
That's insane. These spill heaps always end up killing people, all so the mining company didn't have to pay to dispose of it.
I mean, you could sell salt ffs why just dump it? And what happens when it rains, surely it's absolutely fucking that soil for years to come