Weird slag but not slag what is it

>>1117626
Was there any coating on your crucible?

>>1117634
No I don't think so.

Could be some bullshit someone threw in to scam recycling businesses.

Like putting tungsten in gold bars.

>>1117644
I was using soda cans

>>1117674

Did you stir it after it melted?

It might have just gotten stuck to the bottom and been unable to rise.

>>1117674
Aren't soda cans coated? Also could it be remnants from the coloring?

Im honestly spitballing here I know nothing about melting aluminum

>>1117701
In my experience what doesn't immediately burn off floats up as slag. Certainty not something I've seen across the dozen or so melts I've done.

Was it stuck to the bottom or free? If it was stuck it might be some impurities in the crucible that burned out. What type of cruci do you have OP?

>>1117701

Soda cans sometimes have some type of plastic or polyurethane coating on the inside so prevent metallic tastes,and who knows what's used to print on the outside.

There's a minute amount of precious metals in most alloys of aluminum. You might have melted a large amount of cans at a low enough temp that they bonded to the edges of the crucible over time, and this most recent melt hit a higher temp that shocked the metals from the surface.
The higher mass of all the collected precious metal deposits would have a better chance of "congealing" together, the density (compared to aluminum) would drag it to the bottom and it could form a nugget like yours that would settle on the bottom but require a much higher temp to disolve into a molten aluminum composite.

Effectively you may have separated a glob of platinum/silver/gold composite from the aluminum alloy.
I am not familiar with how to separate the three metals further, but somebody more involved with salvaging those metals from computer components may be able to shed some light.

File: WP_20161227_15_26_22_Pro.jpg (2MB, 3264x1840px) Image search: [Google]

2MB, 3264x1840px

>>1117700
Not really. I should try stirring next time,

>>1117709
Pic related. It's a foundry that I think is intended for melting silver but you can set it for any temp between 0 and I think 2500 degrees Fahrenheit. The crucible is graphite. I'm not sure about the volume but the label on the others (it came with a box of about 10 crucibles) say 30 troy ounces

>>1117719
This makes sense. I did not really inspect the inside of the crucible before heating it up but it us very possible it was used to melt silver.

>>1118210
>30 troy ounces
Of silver, of course