One way is to put a trap in the suction so the pump doesn't drain when it's stopped.
Of course, you still need a big vacuum pump or other means to prime the pump for a black start. See documentation for the New Orleans pumps, the subject of much discussion here in the past year. Since you must have the vacuum pump, or a liquid priming pump, in place anyway, maybe you don't really need the big pump to be self- priming.
What pump type are you going to use.
As you are talkig about pumping tailings, are they abrasive, are there any solids etc.
What configuration is the inlet and discharge pipes.
Any suction lift involved - etc.
Give some more detail on the application so we can advise you further.
Normally on a pump this size, it will be self priming by virtue of a vacuum system. If you're planning on a single pump for this service, you're looking at one big pump....depending on other factors, economics of operation might lean toward using two pumps instead, or possibly a vertical pump, maybe mounted on a floating barge, depending on what exactly you are looking to do.