The art or science of reconciliation between the mill and the ore body block model! happy days!
As for CDU - they keep on banging on about their fantastic orebody model - so they should at least have any idead of some of what is going to the stockpile. And for the mineralisation that sits outside the model - well, usually stockpile separately, so you can keep track of what the blend is through the mill.
CDU Price at posting:
$1.76 Sentiment: Sell Disclosure: Not Held