Things which may be of interest to members

[Shark]

digesting the ash in aqua regia is a much better processing route.

Just to be clear, you are saying to just process the carbon directly in AR? I have always heard to be sure all carbon is gone before AR as it would rob some of the gold.

 

[Deano]

In order to be really clear I said to dissolve the ASH from the carbon in aqua regia.
Activated carbon can be ashed anywhere from 500 to 600C as the activated carbon will attract any volatilised gold from the higher temperature around 600C.
This effect is different from straight carbon which will not adsorb volatilised gold and should only be ashed at 500C.
It really is painfully obvious when activated carbon has completely ashed, the only times you may have difficulty seeing the end point is when the carbon has so much metal, usually copper, coating it that it totally hides the carbon ash.
This is not a common occurrence, you have to really work at generating this much copper in solution before adding the activated carbon.
If you do have metal encrusted carbon, keep the ashing bed depth to three particles of carbon deep and run it overnight at 600C.
Deano

 

[Shark]

In order to be really clear I said to dissolve the ASH from the carbon in aqua regia.

I may be getting to old to be reading late at night. Running the ash makes more sense.

 

[BGDOCK]

You’re not the only one , going to re read some of these posts in the morning .