Ann: High Grade Gold Results at Hillgrove, page-170

It sounds very much like the initial plant metallurgy is well in hand with taking broad large samples across numerous exposed existing working faces ready to mine.
I am only guessing but would say they have a composite sample of around 1 ton or more to mix and match initially grind size for maximum free gold liberation and then probably even finer for further processing needs to be determined.
You don't know what you need plant wise until you work it out.
Numerous times I have heard of upping grind size to increase throughput for next to no loss of yield.

More work goes in these days to getting the best overall processing plant than the old guys guess that this will work for a start and we will work on getting yields better later mentality.

I realise Tungsten can be a bit of a beggar to extract, had shares in Co with a mine in Spain I think it was reworking tailings years ago.That was when Tungsten still went into light bulbs and was cheap.
Took a bit of tweaking from memory to up the quality of the concentrate yield.
Tungsten now is nearly all for machine tools,so cost price is now quite elastic in the scheme of things.

DYOR + DYODD