MrMylar,
The best thing to do to get the gold powder;
Let the gold powder in the sulfuric acid cell settle for several days then SIPHON off the sulfuric acid and save it to use again.
The black gold powder and some residual sulfuric acid will be in the bottom of the container.
Pour this mixture into several liters of water (tap water is OK, but I would use distilled)
Let it settle completely. This may take a day or more.
After it has settled completely, siphon off the clear liquid sitting over the settled black gold powder.
Repeat with several more liters of water, then your black gold powder should be free of sulfuric acid to the point where it can be filtered, or just dissolve at this point with AR.
I have found that diluting the sulfuric acid with large volumes of water and patiently waiting for the gold to settle, and SIPHONING The liquid off rather than trying to pour it off are the key points to getting the gold powder out of the strong acid.
kadriver