My numerous sluicing trips have produced about a bucket of black sand concentrates, which contain micron (mosquito eye) sized gold. The black sand also has some flakes which are heavy and appear to have a blue (almost sky) color and a number of pinky nail sized black opaque crystals which have a reddish/brownish (almost rusty) color. This color becomes more black when the crystal is taken out of water.
I would like to leach out the gold from my concentrates and am secretly hoping that the brownish crystals are telluride with gold. I wanted to check with the experts here whether the following process would work.
1) Crush and grind all black sand including crystals to talcum powder size
2) Buy a gallon of industrial strength bleach (4-5x stronger than normal bleach and sold at Lowe's) and pour into bucket with concentrates (half-full with black sand).
3) Once a day stir bucket in a well aerated area and allow chlorine in bleach to leach gold for about a week.
4) After a week, run only the fluid through a coffee filter and transfer to a clean vessel (Pyrex glass). Start lowering the pH with cheap household vinegar. Given enough vinegar, pH will drop below 7 and I'll get some precipitate, which should contain only gold (brown or black residue).
Would this work? Also, instead of wasting lots of vinegar (relatively weak acid), can I just leave the bleach out in the sun to evaporate? Wouldn't the remaining dry residue in the bucket contain my gold salts?
Thanks for your help.