I'm with Jagster on this.
I just can't believe that all the previous miners were that incompetent so as to leave so much on the table and all you have to do is dig it up again and send it back through the plant. I've never been given a viable explanation on why all this is possible. If something sounds too good to be true it usually is.
I bang on about the recovery number because that's where this will fall apart. If they were using a completely different process (dense media, resin in pulp or some other wizz bang tech) then I'd be less hesitant. You can play with residence time versus grind size and reagents to a point. I just think to make this work they will need to regrind to talcum powder to increase recovery and the energy consumed won't make it viable. It can work, and it might, but it will need a high zinc price.
I find the release of recovery rates at the rougher stage kind of weird and the absence of any full process train recovery numbers a bit telling. I might be wrong and like I said maybe it works at $3,000 plus zinc and we'll get there and they'll hedge? It's just not that easy to dig it up and send it back through the same plant. That's money for old rope.
