Never had before... Problem with SMB and AuCl

[Kalf999]

I have done many batches with fingers in AP , solve in HCl-Glorox and drop down with SMB...

Yesterday I took another batch of 200 grams of fingers , fingers came of in AP , solved them in HCl-Glorox (turned yellow as it should be)...

Then I added the SMB-solution....(I used enough SMB , so that will not be the problem)

Within 5 seconds the yellow color disappered and the liquid became colorless... ( as it always does....)

But then I waited and waited...and it never went brown !!!!!...... So here went something wrong.
Even no dropped down gold after 2 hours...
I will settle it overnight... But in the mean time........ Has anybody suggestions..???


Best regards, Frans Kalf

 

[glorycloud]

You could add some more SMB and stir vigorously. That helps when I encounter what you are describing. Of course 200 grams of fingers may only produce 0.8 grams of gold depending on how good the fingers were.
A good average is 2 grams per pound on newer fingers.

200gr / 500gr per pound = 40%
40% x 2 grams per pound = 0.8 grams

 

[butcher]

you also may have alot of oxidizer (bleach) free chlorine, heat can help to drive it off, it could be re-oxidizing the little bit of gold in solution,

 

[Kalf999]

The fingers are the usual material from different PCB's.

I have added a saturated solution with 10 gms of SMB, but also that gives no reaction..

Not even 1 molecule is coming down... :shock:

 

[lazersteve]

Does a stannous test show gold in solution still?

Steve

 

[Kalf999]

Hello Steve,

Yes , Stannous Test was 100%.

In the AP was approx 1/2 pound of fingers.

Yesterday I tried another thing to find out what is going on...
I have took apart the saturated SMB-solution with the solved gold in it. (Solution I , which is 500 Milli-liter )
Then made another batch HCl-Cl with 0.5 grams of 24 Krt goldfoil. (Solution II, 100 Milli-liter )
I added a small ammount of Solution I to Solution II. Immediate reaction took place. Became colorless, after a few seconds darkbrown, and after 30 seconds gold started to drop down.
I stirred Solution II well. Now I poored Solution II into Solution I. The solution became pale light brown,after 10 or 20 seconds it seemed that the solution became more lighter. But the dropping down of gold was delayed.
I let it settle another 12 hours, and today almost 1.0 (So 0.5 grams more !) grams of the gold was dropped down, but after testing there is still some gold in solution...

In total there should be approx. 2.0 grams of gold (Initial 1/2 pound of fingers = approx. 1.5 grams + 0.5 gram from second batch) , for now I have recovered 1.0 gram.


...... :shock:

Best regards from a snowy Netherlands,

Frans

 

[butcher]

all that snow, and no heat to dissapate chlorine from solution ?

 

[Oz]

I agree with Butcher. I have said before, give it a boil and set to the side, you will likely wake up to a pleasant surprise in the morning. If not you have lost nothing.

 

[markqf1]

If all else fails, cement it out with copper.

Mark

 

[Kalf999]

Hi all,

Heating did not work....

Final thing to do is try to cement out with copper then...But I never did that before..

Can I put a piece of copper (attached to some rope) in it and for how long do I need to let it react then..?

Best regards, Frans Kalf

 

[Harold_V]

Can I put a piece of copper (attached to some rope) in it and for how long do I need to let it react then..?

Don't use anything that can absorb values. Rope is not a good idea, nor is it required. Use a thin sheet of copper if you have it at your disposal. Place it carefully, by hand, and don't allow it to drop, which always presents a risk of breaking the vessel. Wear protective gloves to avoid staining your hands.

Because the values will cement on the surface, the more surface area you present, the faster will be the cementation process. Don't use wire---it can end up as part of the harvest. Don't use pipe or tubing unless you can dissolve it totally in the recovery process, or if you can clean the interior after the values have been cemented.

This process is no different from cementing silver from a nitrate solution. The only real difference is that you likely have very little gold that must be recovered.

If you prefer, you can effect the recovery using zinc, steel or aluminum. Problem with them is that you will recover copper as well. This process should be viewed as a recovery procedure, not a refining procedure.

Luck!

Harold

 

[Kalf999]

Hello Harold,

Thanks for your info.

Some contamination is not a problem for me.
I only want to recover the gold. Maybe some day I also want to refine, but I rather like the recovery-process
As I have a Coin & Stamp-shop I also buy a lot of scrap gold,bullion, rings, etc, etc . So I do know some refiners, that can refine it for me, if I 'd like.

Many thanks & regards from a snowy Netherlands,

Frans

 

[Anonymous]

There may be another explanation for the spurious results. I've gotten bad SMB from Shor in the last few months. My refining friend in Maine has had the same experience. His had solid chunks in it at the bottom of the bag. I think their stuff is old and has been wet. When we complained they said we'd gotten it wet and then wouldn't return our calls.