Stefan you claim to be a professional however you seem to be working under the assumption that all ore deposits are uniform through out!
Another question why is it going to take that long to come on line?
Could be it there is a few hundred million of tonnes of 58%ore in front of it?
Likely I'd suggest.
As posted earlier I'll take the word of a proven project management team at fmg over the ramblings of a self proclaimed expert on hotcopper always.
A self proclaimed expert on hotcopper that jumps to incorrect conclusions then digs themselves in so to speak to a point where other posters label them the Indonesian Scrap metal King.
Suggest going forward you take announcements from the majors at face value as you are no where near as good as you think you are!