yellow foam

[Anonymous]

I refine in aqua regina ceramic and plastic CPUs both in different containers. After ad urea in container with ceramic CPUs it has appeared on surface yellow foam (thick layer), and mud on the bottom same color. In container with plastic CPUs everything is normal, I've ad MB and on bottom I got black dust. I don't know what to do with this yellow foam and mud? Please help!!!

 

[eagle2]

Hello Franek, Welcome to the forum.

The fellows here will all try to help.

We need a little more info. Did you use Nitric acid first, to eliminate most base metals, before you used Aqua Regia (AR) ??

Al

 

[Lino1406]

Foam - skimming, mud - filtering