pluses & minuses, page-67

Yes. A ball mill is a form of mill/crusher. It uses lots of large heavy balls to crush and grind material. It's actually a very simple and standard mine processing machine. In our case it does the first level grind of the material that is then fed into the isa mill.

Btw. I've completely lost the point of this entire thread of discussion. Are people trying to understand the pgi processing process, understand what could have gone wrong and what it implies, or discuss proposals to take to management to train their engineers?