A shift in copper mining practices
HPGRs are steadily becoming ubiquitous in the copper mining industry, replacing the SAG mill grinding stage.
The HPGR exposes feed material to very high pressure for a short amount of time. The compression typically causes the rock to crack and cleave along the grain boundaries, weakening the rock structure. This high pressure also creates a large amount of fines and causes the formation of microcracks in the larger particles, lowering the Bond work index of the ore which, in turn, reduces both ball mill loading and power consumption. The higher the pressure, the more fines (“final product”) are produced.
