pure speculation report, page-20

the issues with the crushing circuit to the concentrate stage are not complex and can be resolved quickly

the issues with recovery need to be put in perspective. What we are trying to achieve here is a world first, around 90% gravity only recovery. Gold in sulphide, as distinct from the gold in the quartz reef which is "free milling", is incorporated into the metallic structure of the host sulphide mineral such as pyrite. This is the gold in the diorite surrounding the reef. This is the gold that is hard to recover and causes the issues.

Gold processing plants use cyanide circuits to help recover this gold. Gekko make a circuit called an in line leach reactor that does the job

http://www.gekkos.com/pages.php?page=40&lang=3

The short term solution is to ship the concentrate out to a plant that uses this type of circuit. Since the reported grades of the concentrate where upto 18000gpt, each tonne of concentrate contains up to $700,000 of gold

In fact GMA when they ran the mine used to ship the sulphide concentrates to Port Kembla for recovery

GMA had a seperate circuit for the diorite. I am getting my info from Bert Masons's book and he doesnt make it clear whether they ran the diorite in seperate batches from the quartz through the crushing machinery

The grade of the diorite was 4.6gpt.

Once thing is clear, what they learn now as the commission the plant will be invaluable when they develop other mines.