Ok Tedi Mine is located eighteen kilometers from the Irian Jaya border in the Star Mountains, Western Province, Papua New Guinea. Sequential flotation concentrators produce a copper / gold concentrate for market, and a pyrite concentrate for environmental containment, with low sulphur tailings from the pyrite flotation sequence being discharged to river._x000D_
Strict sulphur assay targets are set for the riverine discharge._x000D_
Current porphyry and skarn ore blends from open pit operations at Mt. Fubilan will cease by 2017._x000D_
However, drill cores indicate an economic ore body in the skarn ores surrounding and below the current pit limits._x000D_
With proposed mining from a western pit wall cut back' and an eastern pit wall underground operation, potential for ore ageing in sub level cave underground stockpiles is apparent._x000D_
With little information in the literature, Ore Ageing test work at prefeasibility level consisted of multiple one tonne stockpiles of -50 mm crushed rock._x000D_
For the bankable feasibility study, a successful test work program was implemented utilizing 40 tonne ROM ore stockpiles composed of exposed pit extensions of future ores._x000D_
Realistic ageing profiles of Skarn ores were obtained from one tonne monthly samples subjected to laboratory testing._x000D_
Test work outcomes included: Similar ore ageing profiles from both the pre feasibility study (PFS) and feasibility study (FS) programs, suggesting ore susceptibility to oxidation has greater effect in ore ageing than rock size for Ok Tedi skarns._x000D_
Laboratory rougher flotation of pyrite showed significant variation in sulphur recovery rate, suggesting three classes of pyrite floatability._x000D_
Laboratory rougher flotation of both copper and pyrite for up to 19 months ore ageing from 11 stockpiles, suggested three stages in the ore ageing process._x000D_
FORMAL CITATION:Morey, M and Cantrell, R, 2011. Ore ageing test work for the Ok Tedi Skarns, in Proceedings MetPlant 2011, pp 615-629 (The Australasian Institute of Mining and Metallurgy: Melbourne).