Ann: MOU with Noble Group to Facilitate Monetising Stockpiles, page-34

Ore 200kt
Assume copper grade (excluding credits) at 1%
Recovery at 80%
Copper aud/t $9426
Value of contained copper: $15.1m

Of course we still need to account for all the cost. Likewise it is very sensitive to grade and recovery rate assumption... but IMO recovery can only improve to 90% ish through further optimisation work.

The 'stockpiles' are made up or both slag and actual stockpile by the old timers, and depending on the ratio average grade can be higher than 1%. Slag is mostly in the vicinity of the smelter and everything else is likely to be actual stockpiles.