Final Cleanup of Fingers

[Paige]

Steve,

Wow! What a load of gold in 5 pounds of fingers! Now, the final cleanup. I understand 3 flushes with water, and then 3 with HCL, then another w/ distilled H2O.

But what about the bits of plastic I see floating in the water?

Should I heat the gold, say at 500 F to burn away stuff and then clean again?

There is some dark stuff which may be the backs of fingers??????

Thank you.

Paige

 

[lazersteve]

Paige,

Five pounds of fingers will make a nice ball of mash, between 11 and 15 grams depending on the finger quality.

The bits of plastic are from the GIGO I told you about... I pick mine out if I mess up and allow some into the mix. Hopefully you did a good preliminary sorting and cleaning before you started in order to minimalize the garbage out.

If you processed the finger 'shavings' you spoke of earlier, then you've got a bit of garbage plastic in the mix. If so just dissolve the flakes into AR or HCl and Clorox. This will remove the black oxides (?) you spoke of from your description, if I'm hearing you right. The plastic shavings will burn up with the torch but they make toxic fumes and leave a syrupy crust.

The black bits may also be surface mounted resistor arrays if you didn't trim them off good in the harvest stage... a picture would help me guide you in the right direction here.

I would not melt the gold or process further until it's completely free of this miscellaneous debris.

Send me a photo and I'll let you know what I think.

Steve

 

[AuMINIMayhem]

steve.. could he "smelt" what he has left and break of the glass/plastic shavings then remelt?.. just a thought (trying to understand the whole process, myself)

 

[Paige]

Thank you, Steve. I'll pick out the garbage, then go with HCL & Bleach......all before AR.

Paige

 

[lazersteve]

Paige,

You don't have to do both HCl-Clorox and AR, just one or the other.

Steve

 

[goldsilverpro]

Steve,

In your process for fingers, do you filter before dropping the gold? Won't filtering remove the slivers or the bits of plastic?

 

[lazersteve]

Chris,

In the version of the reaction I've been using the desired result is to keep the gold in solid foil form at all times and not to let it dissolve. This method doesn't suffer from the proverbial 'where did my gold go?!!' problems so many newbies have. When you can see the gold there is no question where it is. There is a version of this method that will take the gold into solution, but I try to avoid that portion of the reaction until the foils are removed from the boards. To answer your question, Yes, by dissolving the gold foils the debris will remain as solids in the reaction vessel. This is typically done with AR or HCl-Cl as the final cleanup phase and is optional depending on the desired purity of gold you want to achieve. I prefer HCl-Cl as it doesn't require Nitric Acid or Urea, plus the fumes are not as bad (still bad just not as bad). Just dissolve the foil/powder and percipitate with SMB.

When I started out using this method, purity was secondary to just getting the gold out. At that point in time I just cleaned the gold really well in the cupel and poured it into the mold. Now my mind set has changed and everyhting gets purified with HCl-Cl after being recovered as a powder or foil.

I'm posting a video of an SMB percipitation later tonight. I'm doing the final edit as we speak.

Steve

 

[AuMINIMayhem]

sweet.. another tutorial! Looking forward to it!

 

[lazersteve]

It will be ready within the next 15 minutes.

:wink: Steve