Looking for learning,

[Yggdrasil]

but one of the reasons is excess SMB so I think adding SMB will not work, I think just boil until almost dry then add HCL, do this about 2 times,
I send updated picture, the water color has started to turn green although I don't know why this green color???, I tested for stannous chloride and it was negative, but the Gold's color is still bad and not as hard as I thought, so will refine it a second time

If the stannous is negative then the cause is one of two things.
1. No Gold
2. Stannous is too old

 

[leHAI]

If the stannous is negative then the cause is one of two things.
1. No Gold
2. Stannous is too old

thanks for bringing up the cases, it is absolutely necessary, my case is definitely number 1, but the problem is the quality of the precipitated gold is bad, I will refine again, hope this refining will produce fine gold

 

[Yggdrasil]

thanks for bringing up the cases, it is absolutely necessary, my case is definitely number 1, but the problem is the quality of the precipitated gold is bad, I will refine again, hope this refining will produce fine gold

It is quite common to need a second refine.
That is why cementing on Copper is much used as the first step.

 

[kurtak]

but the problem is the quality of the precipitated gold is bad

What makes you think the precipitated gold is bad (not clean) ?

Kurt

 

[leHAI]

What makes you think the precipitated gold is bad (not clean) ?

Kurt

The precipitate is black, very fine and tiny, does not form pellets, and sometimes dissolves in water.

 

[Yggdrasil]

The precipitate is black, very fine and tiny, does not form pellets, and sometimes dissolves in water.

No Gold will dissolve in water.
If it dissolves in water it's not Gold.
Just to refresh.
What was your starting material?
How much was it?
Are you sure it is Gold there?
It is entirely possible that there is so little you really can not easily see it.
So please, some information on this might help.

 

[leHAI]

No Gold will dissolve in water.
If it dissolves in water it's not Gold.
Just to refresh.
What was your starting material?
How much was it?
Are you sure it is Gold there?
It is entirely possible that there is so little you really can not easily see it.
So please, some information on this might help.

I am sure it have gold, The raw material is a thin plastic sheet like a sheet of paper, on top of which is a layer of glue, a layer of paper, a layer of copper, a layer of nickel and gold.
maybe I still not denox all nitric lead to precipitated gold still in tiny, but I see progress in the precipitation, the latest precipitation gives a more solid form.
I just finish pour SMB to solution , wait to share result with you all

 

[Yggdrasil]

I am sure it have gold, The raw material is a thin plastic sheet like a sheet of paper, on top of which is a layer of glue, a layer of paper, a layer of copper, a layer of nickel and gold.
maybe I still not denox all nitric lead to precipitated gold still in tiny, but I see progress in the precipitation, the latest precipitation gives a more solid form.
I just finish pour SMB to solution , wait to share result with you all

How does the plastic sheet look like after AR?
I'd suggest using Cupric Chloride to dislodge the foil from the sheet.
How many grams of sheet do you leach at a time?

Edit for spelling.

 

[Yggdrasil]

I am sure it have gold, The raw material is a thin plastic sheet like a sheet of paper, on top of which is a layer of glue, a layer of paper, a layer of copper, a layer of nickel and gold.
maybe I still not denox all nitric lead to precipitated gold still in tiny, but I see progress in the precipitation, the latest precipitation gives a more solid form.
I just finish pour SMB to solution , wait to share result with you all

There is a saying that goes so:
Crap in, crap out.
Which means in simple terms if you put trash into a process you will get trash out.
(Maybe less than you started with.....)
The energy you spend on preparation and cleaning your feed stock will pay dividends in the end.

 

[leHAI]

How does the plastic sheet look like after AR?
I'd suggest using Cuproc Chloride to dislodge the foil from the sheet.
How many grams of sheet do you leach at a time?

I put them to HNO3 + H2O solution and Gold layout run out, this step is simple but take time
I have about 800 gram at this time
I update the photo of 2nd drop by SMB, it's seem less gold then I am image,

 

[Yggdrasil]

I put them to HNO3 + H2O solution and Gold layout run out, this step is simple but take time
I have about 800 gram at this time
I update the photo of 2nd drop by SMB, it's seem less gold then I am image,

You did not answer my question.
Do the plastic dissolve in the AR or Nitric?
Or is it pure whole foils?
I'd guess ther might be a few mg of Gold in 800g of sheets.
Do you have a picture of the sheets?
Ideally before and after leaching.