Gold in dust

[hrushi]

Hey Guys

Need some help

I had some dust which I processed in Aqua.
I tried precipitation of gold by using HH, Ferrous sulphate and Zinc in all three I got some sticky jelly type precipitate which would not settle nor filter using high vacuum.

By using Ferrous sulphate I got grey colored
By using HH I got bark brown colored
And by using Zinc I got golden colored

So I have filtered using gravity it took long time, and I had re-dissolved it in aqua
What should I use to precipitate Au Now
It has good content of Au

Regards
Hrushi

 

[Lino1406]

Same reducers, or ascorbic acid, or copper foil...

 

[butcher]

Gold dust, what is that?
Does this gold dust come from electronic scrap or some other mining process?

The picture looks like lead, tin, sludge with some copper in solution (or a big mess which makes it easy to lose your gold)

 

[hrushi]

Gold dust, what is that?
Does this gold dust come from electronic scrap or some other mining process?

The picture looks like lead, tin, sludge with some copper in solution (or a big mess which makes it easy to lose your gold)

Silver refining sludge

 

[nickvc]

Is this sludge from a silver cell?
The recommended method is to boil this material in a cast iron vessel using dilute sulphuric to remove the silver and other base metals, this leaves a better concentrate to recover the gold from.
If that doesn’t appeal maybe filter and well rinse the sludge, dry and melt into shot and digest again in nitric which should leave your gold in the bottom of your vessel.
If you have tried to use AR to recover the gold then you now have silver chloride to deal with so convert back to metallic silver by the method of your choice filter and rinse and then melt into shot and digest in nitric.

 

[hrushi]

Is this sludge from a silver cell?
The recommended method is to boil this material in a cast iron vessel using dilute sulphuric to remove the silver and other base metals, this leaves a better concentrate to recover the gold from.
If that doesn’t appeal maybe filter and well rinse the sludge, dry and melt into shot and digest again in nitric which should leave your gold in the bottom of your vessel.
If you have tried to use AR to recover the gold then you now have silver chloride to deal with so convert back to metallic silver by the method of your choice filter and rinse and then melt into shot and digest in nitric.

Not exactly silver cell but I have dissolved silver in nitric
As you suggested I have washed it properly removed all nitrates and then roasted it in iron vessel then added AR to recover gold. precipitate of gold powder I am getting its very fine and spongy
My doubt it contains tin, lead.

regards
hrushi

 

[nickvc]

After roasting if you still have some available do some samples try using HCl in one and sulphuric in another and see if the results are better, going straight for AR was probably a mistake so find another process such as I suggested above.