Ann: Major Extension At Mount Hope Central - 36m @ 2.2% Cu, page-98

Chalcocite metallurgy depends on if its primary chalcocite (which floats extremely well and is often associated with Bornite) or secondary chalcocite which can be a pain in the rear for traditional sulfide flotation plants.

Some other examples of difficult Cu orebodies that have their challengers are:

Nifty is an excellent example of how not to plan and operate what should have been a complex oxide and sulphide copper profitable orebody (currently owned by CYM who are in all sorts of trouble, Nifty is famous in the industry for being a "company killer"), TMS's Bluebird Deposit in the NT has sat around unloved for a long time, Copper Mountain just sold the Mt Roseby group of deposits north of Cloncurry to Harmony and they are back drilling again (many previous owners & mixture of oxide, supergene and sulfide orebodies) and the famous example is, of course, the Rocklands Project first mined by CuDeco (although their challenges were more management & incompetence and resource estimation related).

These CNB guys want to stay well and truly clear of True North Copper - they are a bit dodgy in their dealings from memory.