RE:RE:RE:RE:RE:CSK....All true Rockport1. The problem is that the gravity+flotation concentration process only gets rid of 60% of the mined material, not 90%+ so the recovered metal is in 40% of the mined material, far too much, so the concentrate is very low grade, far too low at 2 grams per tnne to be economic.
The 2 gram concentrate is worth about $140 per tonne at current gold prices.Refining of the concentrate will cost on average of about $75 per tonne to get the metal and transporting the concentrate to the refinery will cost $25-$50 per tonne. Let's say $25 to be optimistic (although transportation costs are sreaming higher).So, out of $40 per tonne remaining, you need to pay for mining, milling and concentrating, capital, offsite overhead and shareholder profit. Can't be done.
The 88% recovery is good...that's not the problem. The problem is that the recovered metal is chemically or mechanically bound to a very large amount of waste to result in a very low concentrate grade. A 70% recovery in a concentrate of 5% of the mined ore volume would be far better.