Just a question if my incineration was too hot? And if this could be a problem

[Akozak]

-I used a stainless steel cup.
-250g mixed ic chips.
-Inside a propane foundry.

My incineration went well to my knowledge. I tried panning the powder just to see my results. And I got very little visible gold. I did see dozens of metal balls all different color and shape.
My question is, has most of the gold combined itself with thesse melted metals balls?

 

[eaglekeeper]

I would say a little to hot, some of the gold bonding wires probably alloyed with the base metals. also, It would be difficult to see the bonding wires from just 250g of IC chips.

Bonding wires don't pan out very well, a lot of surface area for the water to act on. I've also tried using a Blue bowl set up for bonding wires...... not very effective for separation either.

 

[orvi]

Usually solder melts first and alloy with whatever is present. Assuming your incineration went past 600-700°C, solubility of copper in the melt of Sn/Pb significantly rises - so it also can hit that golden colour as we see, but I think it is just some oxidation going on the surface.
If these are solder balls, collect them as gold could easily dissolve in these during the process.

 

[Akozak]

Okay I know I

Usually solder melts first and alloy with whatever is present. Assuming your incineration went past 600-700°C, solubility of copper in the melt of Sn/Pb significantly rises - so it also can hit that golden colour as we see, but I think it is just some oxidation going on the surface.
If these are solder balls, collect them as gold could easily dissolve in these during the process.

Ah Yes I know now I definitely went over the limit. I wanted to make sure I didn't have any un burned parts.
For the next batch you would recommend a graphite crucible. Or can I still use my stainless cup for incineration?

I added a pic of my setup.
I use propane welding torch
(not acetylene) and add oxygen if I need too

 

[dpgold]

-I used a stainless steel cup.
-250g mixed ic chips.
-Inside a propane foundry.

My incineration went well to my knowledge. I tried panning the powder just to see my results. And I got very little visible gold. I did see dozens of metal balls all different color and shape.
My question is, has most of the gold combined itself with thesse melted metals balls?

did you incinerate plastic and ceramic chips toghether? Any problems with that?

 

[4metals]

I'd say the solder took all of the metals into one alloy because it was too hot. The tin will cause problems if dissolved in a reaction to refine the gold, I would suggest hammering the balls flat to increase the surface area and dissolving out the tin in Hydrochloric Acid.

 

[orvi]

I'd say the solder took all of the metals into one alloy because it was too hot. The tin will cause problems if dissolved in a reaction to refine the gold, I would suggest hammering the balls flat to increase the surface area and dissolving out the tin in Hydrochloric Acid.

It could be hidden culprit, but most of the times, AR raffination will leave the tin in the solution (if free HCL content is sufficiently high). Otherwise, this could be flux-washed during the melting process - if the content of Sn isn´t in the margin of %.

 

[4metals]

It could be hidden culprit, but most of the times, AR raffination will leave the tin in the solution (if free HCL content is sufficiently high). Otherwise, this could be flux-washed during the melting process - if the content of Sn isn´t in the margin of %.

True, true, and true. But, (ain’t there always a but?) he somehow confused incineration with melting so flux washing and trapping the oxides in the slag is probably not in the cards. Beating the bead with a hammer and dissolving the tin with Hydrochloric Acid is a simpler means to an end.

The last thing you want to do is end up with an excess of stannous in the acid making gold colloids which are a nightmare to filter and recover.

 

[orvi]

True, true, and true. But, (ain’t there always a but?) he somehow confused incineration with melting so flux washing and trapping the oxides in the slag is probably not in the cards. Beating the bead with a hammer and dissolving the tin with Hydrochloric Acid is a simpler means to an end.

The last thing you want to do is end up with an excess of stannous in the acid making gold colloids which are a nightmare to filter and recover.

Exactly as you say. Wise words, as always

I will just add that ultrasonic bath can speed up the process quite a bit. Also could be helpful if one dissolve karat - to break and "dross-off" the AgCl crusts, liberating somewhat more "fresh" surface of the alloy.
I think that he does not posses one, but I wanted to generally add this