Non-Chemical Gold powder cleaning question.

[skyline27]

I melted some gold powder last weekend. It was from foils stripped in AP, washed in 3 soaks of HCl, dissolved in HCl-Clorox, dropped with SMB, 2 rinses hot HCl and 3 rinses hot water. I don't think it was as clean as it should be because it made the flux purple when the powder was added to the melting dish.

Should I have included a rinse to remove silver? Is that a potential contaminant in fingers?

When I'm washing the powder in alternating hot HCl and hot water, should I break up the big clumps of powder to let the water/acid penetrate?

Any advice would be appreciated. I'm sure I can improve my methods for next time, I'm just not sure how. Melting the gold is my favorite part of the whole process!

 

[jimdoc]

Purple is OK, it is gold.
Jim

 

[Noxx]

Exactly,
Purple colour is colloidal gold.

Don't worry my friend, I'm pretty sure you have a quite pure gold in there ! :lol:

 

[Lino1406]

If you have seen white suspension in there?

 

[skyline27]

"If you have seen white suspension in there?"

I don't understand the question.

 

[Lino1406]

According to your procedure, silver, if any,
would appear as white suspension (or precipitate)
so you'll know if "silver rinse" is needed

 

[skyline27]

No. There was nothing silver or white. Just pale brown/red mud.

If there is silver, at what point will it become visible? I'm planning on processing some Pentium Pros and expect silver.

 

[Lino1406]

In 1st stage