Lend me your knowledge please?

[Howardmark84]

I work as a machinist in an industrial equipment repair shop. Once in a while we get compressors from chemical plants that have gold plated seals in them. We always end up making new seals, which are steel, then send them out to be plated, when they come back they have around .010" thick 24k gold plating, which I then have to cut to achieve a certain size. I have saved my shavings from these cuts for years and have around 2oz of gold. I have used a pmi gun to check and it reads 100% pure AU. Sounds great right? Well my issue is I take my shavings to be smelted and they won't melt at normal melting points, the guy at the smeltery is at a loss as am I. Does anyone have any idea why?

 

[acpeacemaker]

I work as a machinist in an industrial equipment repair shop. Once in a while we get compressors from chemical plants that have gold plated seals in them. We always end up making new seals, which are steel, then send them out to be plated, when they come back they have around .010" thick 24k gold plating, which I then have to cut to achieve a certain size. I have saved my shavings from these cuts for years and have around 2oz of gold. I have used a pmi gun to check and it reads 100% pure AU. Sounds great right? Well my issue is I take my shavings to be smelted and they won't melt at normal melting points, the guy at the smeltery is at a loss as am I. Does anyone have any idea why?

You said yourself its plated steel? Steel has a higher melt point.

 

[Howardmark84]

There is no steel in what I have collected. It is only gold shavings. The steel never gets cut, it goes into the machine and back to the chem plant.

 

[g_axelsson]

Then the temperature of the gold wasn't high enough.

Göran

 

[Howardmark84]

The smelter was above and beyond 2000 Fahrenheit. Gold melts at 1950. I thought of this too. The person I had attempt the smelt is reputable, he runs a very nice gold exchange and he is puzzled.

 

[Barren Realms 007]

Can you post a picture of the material?

 

[cnbarr]

Send a half gram to a lab for assay to find out what else is in there, the only way it wouldnt melt is if it was alloy with a I higher melting temp metal.

 

[FrugalRefiner]

Hopefully goldsilverpro will be along. He has taught us that gold plating is rarely pure gold. Other metals, like cobalt, are often used in small amounts to produce a suitable plating, especially the kind of thick coating you're talking about. He can probably provide some valuable insight.

Dave

 

[Howardmark84]

I will post a picture asap. I had the same thoughts about there being an alloy, but a pmi gun breaks down every element in the metal and it shoots nothing but gold every time.

 

[cnbarr]

I'm sure theres some nickel in there as well, they wouldn't plate directly over the steel I'm pretty sure they would have plated with nickel first.

 

[goldsilverpro]

There's not enough Ni or Co (about 0.1 - 1.0%, max) in the hardened gold to make much difference in the melting. Either it wasn't hot enough or there's some other metal with the gold. That's about the size of it. I would want it to be a bit hotter than 2000F. Cheaper furnace temp gauges are often off and can be a lot off.

 

[resabed01]

Are you positive it's gold? Titanium coatings appear golden... and they are quite hard. Titanium drill bits for example.

 

[Howardmark84]

I'm positive it's gold, I have shot it with a pmi gun at my job and also two different gold buyers have shot it with their guns, all 3 guns came up with 24k gold. Btw thanks to everyone for the responses I appreciate you all scratching your heads with me over this.

 

[goldsilverpro]

I'm positive it's gold, I have shot it with a pmi gun at my job and also two different gold buyers have shot it with their guns, all 3 guns came up with 24k gold. Btw thanks to everyone for the responses I appreciate you all scratching your heads with me over this.

What is a pmi gun?

 

[cnbarr]

It's an XRF with the acronym pmi, positive metal identification .

 

[Howardmark84]

Photos still coming, I'm at work but as soon as I'm home I will get them posted.

 

[Howardmark84]

Ok here are pictures of the gold shavings.

 

[shmandi]

I think it will be better to refine it first and then melt.
That way you will know for sure what you have.

 

[rickbb]

Try melting a small amount in a melting dish with a oxy/acetylene torch.

You could also try shaping some with a hammer, pure gold will be soft enough to combine bits together and mash into shapes with not much effort.

Any resistance to hammering or melting would indicate that you have more than just gold there.

The XRF guns are only looking at the surface, not even a few molecule's deep.

 

[Lou]

Happy to take a look at it for you.

Lou