Sorry to hear you are struggling with fine gold separation from black sand. It's definitely an art! Have you tried classifying your cons with 12/30/50 mesh screens? How about using a magnet? Jet dry?
...with these tools you can really zip thru the cons!
I do ALL that. You know the type of gold that comes out of the the Arkansas. It's almost all -50. I can get the bigger stuff easy, it's the smalls that kill me.
I screen all my cons, then pan out the over-size material, just in case there's a picker in there, or any under-size that didn't go through.
Then I put all those -50 in a tub one scoop at a time and run a magnet through it (under water since its all wet already).... it's about 75% magnetics.
Then all those iron sands are dried in the sun and re-magnet screened because material always gets stuck in there on the wet pull. There is always good gold in this!
Now, all that non-magnetic material gets run through the concentrator sluice to give me my super-cons.... but all that is the easy part. BTW, all that reduces about 5 gallons of cons to about 1/2 of a gold pan full of super cons.
Next comes finish panning all my super-cons, and it has to be done a kitchen-spoon full at a time, at probably 1/2 hour per spoon. Why does it take so long? The super cons are 90% non-magnetic blacks, garnets and gold. The flour gold doesn't settle to the bottom easily. SO it goes.... shake the cons, slowly wash away the top material until specks of gold begin to show, rinse out the stripped material, re-shake the cons...etc. etc. If you go too long, the flour gold begins to move and wash into the stripped cons.
Every spoonful has 100 or more colors in it, so it's either work it slow or wash the majority of my gold away which brings me back to my post.... take the time by hand or melt.
If you have some super-secret method I'd love to hear it.
