It is really not that hard, Fons. I can't believe more people haven't done it. If you're serious, you should ask Bob to meet you there. If he has time he'll show you anything you want to see. He's always been very forthright and congenial. You can do a "head count" on his great employees and the equipment there.
On the way back take a few minutes to see the ore at the port. You can see it from the embarcadero or pay one of the boat owners $10 to take you over for a close up look.