On top of what you say about front-loading the mine schedule to...

On top of what you say about front-loading the mine schedule to reduce the payback period and boost the NPV, over the longer term, being able to stockpile different grades of ore can also greatly assist in maintaining profitability throughout the copper price cycle for longer term, multi-decade operations. When the copper price is high you can use more lower grade ore and retain profitability on lower margins and when the copper price is depressed you can use more of the higher grade ore to sustain you through the lean times when its not possible to make money on just the lower grade stuff.

I have a question for the boffins. If ore is near surface is it right to generally assume that it is oxide? Can oxide be sold as concentrate or does it have to through SX-EW? Can oxide and sulphide ore be blended and processed or blended once made into concentrate?