Basically we have two zones one is the oxide zone, very basic...

Basically we have two zones one is the oxide zone, very basic explanation this is a close to surface zone where water/oxygen/carbon dioxide has replaced the sulphides unlocking the gold making it much easier to recover.

The zone below that which holds the fresh rock, down there the gold is still trapped in the sulphides making it much hard to extract, usually you are looking for 80%+ recover from fresh zone or you need to use additional expensive methods to treat the ore, then it is consider refractory ore.

AOP is looking much lower than that right now, from my experience you have several options.

1. If the fresh material is higher grade average of 5 g/t+ material you can process it economically at a lower recovery.

2.You can blend it with oxide material if you have alot of it, AOP seems to have a decent amount.

3.You can just take the top 60m oxide zone and forgot the rest.

I wouldn't call this AOP project completely dead at this point, but speaking frankly it's pretty close the recoveries are really bad, I would explore one of their other projects they have several good ones.