Ann: Very High Metallurgical Recoveries, page-243

Yes and No ... Hard rock can be just as economic or even more so, the grade just has to be relative. Hard rock = Higher capex/opex requires a higher grade that is all.

WA1 is currently uncovering a monster carbonite system with still a low MC currently for anyone that wants to check that out.

In regards to OD6 met results and making comparisons with other Aus plays .. IMO no comparison can be made whilst OD uses HCI ... When processing 5-10 mullion tonnes of feed stock - a 300%-500% difference in acid costs is such a contrast you cannot even read anything in to it.

I am not saying OD6 cannot achieve economic results using sulphuric acid, I am also not reading nothing in to HCI recovery data because IMO HCI would not be economical with the amount of ore to be leached. 10 MT is gigantic when you consider PLS is running 2MT for example. So acid choice is exceptionally important moving forward.