Michael, you have formed waterglass, or soluble silicates. You are right the milling will take the infinitely ductile gold down to very fine particles in that situation. You can do even better under pressure with added CO2 you can dissolve the iron and gold, as this is the way they were mobilised underground. CO2, SiO2, Au, H2O, Fe, As, Ag will all mobilise. Often the loss of the CO2 as the pressure falls causes this stuff to fall out of solution as the gold and quartx veins we see. The CO2 does not fizz out, but diffuses away allowinf for en situ deposition. The diffusing CO2 causes a swath of carbonate modification in the area. Takes eons, and way undergound with pressures and temps above the critical point for CO2, but since it is a minor component is endures as solution to a higher temp.
Bill |
