sulphide versus oxide, page-7

I can only speak from my own experience. I have no mining expertise, my expertise is in mainframe computing and I've occupied senior technical positions for over 20 years.
I regularly have programmers coming to me with questions or "advice". They are intelligent degreed people with an opinion who may have read something somewhere. I'm always polite but almost invariably roll my eyes in exasperation when they leave. You only get the required experience from a lot of time in the job.
I doubt Mr. Phillips reads HC, but if he did I could picture him pushing his chair back and rolling his eyes.
No offence intended to anyone, just an opinion.