Blythe is generally correct, HPGR based circuits are generally 30% more expensive than SAG based circuits, despite what all the HPGR proponents say.
As ores get harder and more competent, this difference becomes less to the point where for a project on extremely competent ore like Boddington, a HPGR circuit may well be te same price or even cheaper as SAG mills dont like really competent ore.
Rocklands is not that hard, so it suggests a SAG circuit would be 30% cheaper as Blyth says. However, as it is a smaller tonnage of only 3 Mtpa, it wont require all the expensive trippers, bins and feeders that large tonnage HPGR circuits require, hence it may not be as expensive as Blythe thinks. You can actually do a low tonnage HPGR circuit quite cheaply in this situation if you try. Still, I concede it wont be as cheap as a well designed SAG circuit. But when you consider the benefits of the HPGR with the gravity circuit, it makes a lot of sense and I think is the right decision.
Hence, in my opnion, Blythe is both right and wrong. However, it appears he has only looked at te bad points, and not the good points.....
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CDU Price at posting:
$3.30 Sentiment: LT Buy Disclosure: Held
