# incineration of plated pins WITH their plastic casing



## frank-20011 (Oct 25, 2016)

hello everyone-again,

i've made some littles test in the past with different material but everytime it was a gold plated metal part firmly connected with its plastic casing...or high quantities so a hand out pulling is an absolute no go.

there was different metals and different plastics but every time after the incineration i'am not able to see the gold plating on the freed metal parts...only the base metal.

i didn't through the objects in a hellfire, i incinerate them very carefully and as "cold" as possible with an reducing flame....an as slow as possible....no glowing of the metal parts.....

i am not shure if the aggressive fumes of the burning plastic made something with the gold (i know...not realistic) ot if the gold diffused into the metal and so it isn't longer vissible?

is there anybody who share my observations or, much better, somebody who is able to explain what there happens?

best regards, frank!


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## Gratilla (Oct 25, 2016)

Consider pyrolysis (instead of incineration). Info here on the forum, on the Web and on YouTube.


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## frank-20011 (Oct 26, 2016)

Hello,

o.k. i should better burn the plastic trash with the plated stuff inside a...lets say a soup can with closed lid (placed in a camp fire for ex. an a little hole in its lid) instead with an open flame at the open air?

but why the gold isn't longer visible after open burning of the whole unit (plastic-plated sheet)?

thanks and have a nice day!

best regards!


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## butcher (Oct 26, 2016)

Plastics produce all kinds of dangerous gases, not only deadly to us and our environment. Some of these gases can react with metals under the high temperatures, gases like chlorides, for example, can dissolve gold (oxidation) and carry it in the fumes, in a closed container if this happens the gold may just cement back out onto copper (reduction).


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## frank-20011 (Oct 26, 2016)

hello an thanks a lot,

dangerous gases like Cl (from PVC) are evident but gases from plastics like PP...but o.k.: i will try a real incineration without air access and than i will report about the resukts!

nice day, frank!


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## butcher (Oct 27, 2016)

At high temperatures, metals can oxidize, some metals are much more reactive, some will react with moisture produced by combustion products and oxygen of the fuel or air. Metals can also be reduced (carbonous products), or melted, some metals are volatile...


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## frank-20011 (Oct 27, 2016)

Hello,

yes, yes but at 500°C gold isn't volatile, it couldn't be oxidised and it couldn't be reduced by carbon even when i burn the whole stuff in an open fire but: i will follow you and will try it in a closed container...
...than i will report my results!

best regards, frank!


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## FrugalRefiner (Oct 27, 2016)

frank-20011 said:


> Hello,
> 
> yes, yes but at 500°C gold isn't volatile, it couldn't be oxidised ...


I can oxidize gold at room temperature with HCl and Clorox.

Dave


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## lunker (Oct 27, 2016)

I asked thaïs question Before on thé forum. I Was told that the gold layer can migrate to the plated layer underneath or even to the base metal itself. Moisture and off gasses like cl could strip metals and put them into a vapor? My experience is that the copper base metal oxidizes and scales off. Taking the pm coating with it. I think that is one reason some of my pulps run high in gold while others don't. Mabey try melting them under a layer of flux? And incinerate the same amount in air and see if there is any degree of loss?


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## frank-20011 (Oct 28, 2016)

hello,

thanks, thanks, thank you very much, i will try it without air contact as soon as possible and then i will report.

nice weekend!


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## butcher (Oct 28, 2016)

Gold(III) chloride can be prepared by passing chlorine gas over gold powder at 180 °C

2 Au + 3 Cl2 → 2 AuCl3 


Gold metal powders can be melted at over 1000 °C in air and poured and cooled without chemical change.


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## anachronism (Oct 28, 2016)

FrugalRefiner said:


> frank-20011 said:
> 
> 
> > Hello,
> ...



I'm sure you can but you're talking about a solution whereas the OP is talking about incineration or did I miss something here Dave? 

Apples and pears.


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## g_axelsson (Oct 29, 2016)

The gold is probably still there, either diffused into the base metal or the gold has been broken up by an oxide layer formed by oxidizing the base metal.

Usually pins have a minimal plating just to protect the surface against oxidation. Other plated details like ceramic CPU lids have a lot thicker plating to protect from diffusing the plating at the higher temperatures used when brazing the lid.
I wouldn't be surprised if the plating hides by diffusing into the base metal when incinerated for quite a long time at high temperature.

Göran


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