SCALE OF OPERATION OF HPGRs

A common perception is that a project must be of relatively large scale before the use of HPGRs can be justified. However, HPGR units of almost any size can be produced (up to the current practical unit capacity limit of about 2,200 t/h), and this technology deserves serious consideration over a much wider range of plant capacities than might initially be imagined.

Ultimately, HPGRs can be justified if they offer benefits to metallurgical performance and/or project economics, and the potential for such benefits can usually be assessed at the prefeasibility study phase by conducting preliminary tests. The manufacturers have test facilities in Germany, and small-scale laboratory facilities are available at various locations globally. Pilot-scale machines are available at several research facilities in Perth, Western Australia, and a Polysius mobile pilot unit used for trials at an operation in North America in 2003 was subsequently relocated to South Africa for evaluation on a hard-rock mining operation.