Gold will not drop

[Yggdrasil]

Thank you very much
Lessons learned so far
1.)Totally agree w/ you about checking the Ph going slower.
2.) Go cold when using HCl and bleach
3.) being on the ball every second should be a mantra .
4.) bought Nitric Acid yesterday

Nitric will make things easier but has its drawbacks.
Use it in VERY small amounts unless for Silver.
Nitric do not like Tin, it creates Metastannic acid which is a nightmare to filter.
Personally I use HCl/Peroxide for small amounts of Gold or PGMs
You need strong Peroxide though, I guess 20% plus is best.

 

[BGDOCK]

First of all the solution needs to be filtered crystal clear before precipitating anything.
For SMB and maybe Coppras too the solution needs to be sufficiently acidic, something that is not the case when using the HCl/Bleach method.

 

[BGDOCK]

Filtered
Solution looks much better
Looking for ph strips now
SMB

 

[Yggdrasil]

What is the pH and how did the stannous test look like?

 

[Yggdrasil]

Filtered
Solution looks much better
Looking for ph strips now
SMB

Oops posted simultaneously

 

[BGDOCK]

I’m sorry I did miss your response

 

[BGDOCK]

The stannous test shows very little black flecks I’m going to make another batch of the stannous
More to follow
thanks agains

 

[BGDOCK]

1.) check, yes I have bought the book and have read it ( rereading as well)
2.) Will do
3.) I do treat my wastes , I seem I have recovered more copper ( using rebar to cement out Cu)

I had asked for clarification/ more details because I had trouble .

I had performed 2 trail runs one with AP on gold fingers the other with magnetic and non magnetic pins.
I combined the two batches and used the HCl & Bleach method to dissolve the gold ( there was some copper I think in the filter media )

I put the filter media in a HCl and bleach solution it was a yellow green color at first but turned black after heating it Stanous solution showed gold in solution but it was a small amount .
My mistakes:
1.) filtration work needs improving
2.) don’t heat HCl / bleach solution
Since the amount was small I just put in the stock and will cement it out w/ copper .

The picture attach was before added the batch of pins .

Edit ; This should have said since the amount was so small I was just thinking of putting it in my stock pot .

 

[BGDOCK]

You learn by reading and studying then doing acquaintance testing.
Maybe post your plans here so we can adjust what is needed.
But only after you have studied the safety and waste treatment section.

Where are you performing these tests?
In a lab, shed, garage or other?

 

[BGDOCK]

Oops posted simultaneously

 

[BGDOCK]

pH looks like it’s in between 6.2 and 6.8.

 

[BGDOCK]

What is the pH and how did the stannous test look like?

Between 6.2-6.8

 

[Yggdrasil]

Between 6.2-6.8

You need to add some HCl to push the pH down below 4 at least

 

[Yggdrasil]

Between 6.2-6.8

This is most likely the reason for your Gold not dropping, not acidic enough.

 

[Yggdrasil]

The stannous test shows very little black flecks I’m going to make another batch of the stannous
More to follow
thanks agains

This is how the Stannous should look like:
Picture by LazerSteve

 

[BGDOCK]

Thanks

 

[BGDOCK]

I have searched for stannous test
My last batch :
30 ml HCl
1 gram stannous crystals
10 grams tin shot ( melted and cut up)

In addition I’m going to prepare a gold solution .

 

[Yggdrasil]

I have searched for stannous test
My last batch :
30 ml HCl
1 gram stannous crystals
10 grams tin shot ( melted and cut up)

In addition I’m going to prepare a gold solution .

I do not use anything else than solder and HCl.
Works like a charm.

 

[Darkthirty]

I do not use anything else than solder and HCl.
Works like a charm.

What is the formula for stannous chloride? e.g. 2g Sn / 1ml HCL? I have 95/5 Sn - Sb solder to work with, everything I'm finding includes crystals or is ambiguous.

 

[Yggdrasil]

What is the formula for stannous chloride? e.g. 2g Sn / 1ml HCL? I have 95/5 Sn - Sb solder to work with, everything I'm finding includes crystals or is ambiguous.

There are many recipes out there, but why make our simplest task difficult.
Fill a 50-100ml bottle with a splash (a few ml) water add HCl to 3/4 full and put in a few grams of Tin solder.
Let it react until the bubbles stop.
Add a cap loosely.
It is beneficial that not all the Tin dissolves if you want it to keep working for a long time.
For your own sake it is wise to write down your own recipe so you make the same strength each time.