# Hmm. Rolled Gold.



## 24CaratHeaven (Nov 4, 2012)

I sell my scrap rolled gold/gold filled items at current to a bullion dealer here in the UK.

Anyway last week i was invited to go and take some more and can watch it done. 

Now they just furnace the whole lot.. No chemicals no messing furnace it to gold and jobs done. 

Is that actually a way of doing it. He is more than willing to show me, However everything i read here claims it can not be done..

I have just short of 110kg of rolled/filled gold watch cases and so on so i am thinking if i can furnace it myself well i may as well.

They have a video of them doing a batch of several carats of gold all in one pot scrape off the swarf ? and hey presto a gold and black bar. Hammer of the black hey presto a fine looking gold bar.


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## butcher (Nov 4, 2012)

If you melt 97% copper with 3% gold that is what you will have in the bar. A bar of copper contaminated with gold.
It would not increase in gold percentage just because you melted it all into one lump, yes a little base metal can oxidize, or if you used flux a little of the base metal oxide would be in the resulting slag glass, but the bar would still be a copper bar contaminated with gold, it just does not work the way you are thinking.

I can see him melting these and selling to a copper refiner.
or maybe he could also be selling to a gold refiner if he is mixing gold fill in the melt with higher karat gold to lower the karat gold content, using the copper from the gold fill, and the little extra gold from gold fill just adds to his paycheck.

For what we do melting your gold fill, making it a bar of copper contaminated with gold will just make it harder for you to get your gold back out of the bar of copper.


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## 24CaratHeaven (Nov 5, 2012)

Cheers Butcher, I guess i am going to have to go and watch it done.

I was just guessing myself that the gold been heavier it would drop to the bottom of the mix of metals. My theory was is it not the same as smelting 9ct gold back to near pure, Ie rose gold is mixed with copper which in a way around is the same as Rolled gold.


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## Geo (Nov 5, 2012)

24CaratHeaven said:


> Cheers Butcher, I guess i am going to have to go and watch it done.
> 
> I was just guessing myself that the gold been heavier it would drop to the bottom of the mix of metals. My theory was is it not the same as smelting 9ct gold back to near pure, Ie rose gold is mixed with copper which in a way around is the same as Rolled gold.



you have quite a bit of learning ahead of you. "rolled gold filled" is a process. an item that is rolled gold filled has been formed in a specific way. its a way of getting a thick layer of durable gold that will stand the test of time but not be as expensive as an item that is Karat gold throughout. the gold and base metal layers are formed in a sandwich or "biscuit" and then rolled into whatever shape is desired. in terms of the 60s common man, gold lives in a world of free love. it will merge and mingle with just about every other metal. gold loves other metals and will physically seek it out. dont believe me? ask around of people who know. gold placed in close proximity with another metal (noble metals especially) will migrate, atom by atom, to the other metal. you can place pure gold and pure silver in close proximity in a vacuum and given enough time both metals will be alloyed together.melting these metals together will cause them to be alloyed faster. the only way to separate them again is to refine them.


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## butcher (Nov 5, 2012)

Many metals when melted together form alloys, like copper and zinc used to make brass, both of these metals alone have very different melting points of each other or than the brass does, but when melted together the brass alloy will now have a different melting point than any one of its individual metals that formed the alloy as copper and zinc.

You cannot separate the alloy by melting points again, as the new metal alloy formed has a different melting point, they are no longer individual metals but an alloy of the two metals in this case we call brass, the metal in majority is a solvent for the other metal, the solid metal also has a different properties than the individual metals used to make the alloy.

The new alloy may be harder or softer than the original metals used to make this new metal alloy. 

The individual metals used to make this alloy will not separate by density in the melt,( I imagine) that the atoms are moving around in the melt so vigorously that all they do is mix together even better, heating of the atoms bumping each other all over the place, as when melting during cooling one metal atom being a solvent of another metal while cooling and solidifying, and when cooled or cooling lock together in atoms of each metal into crystals, binding atoms of one metal into a lock with the other with atoms of both metals marrying then to forming bonds of the crystals.

If this were not the case we would not have many of the metals we have, as any time metals were melted they would separate and would not form many of the very useful alloys we have.

Other wise we could not form alloys by melting two metals, as we would burn one metal up and boil it away before the other melted or got hot enough to become liquid and form the alloy, luckily one metal becomes a solvent for the other metal in the melt, and dissolves it into the melt to form the new alloy, it also has effect on the other metals melting point.

When solder is soldered in electronics to solder gold pins to a copper circuit board, the solder dissolves the gold into the solder, the solder is the solvent, the soldered joint now has a somewhat different property than the pure solder did, now unsoldering the joint will not separate the tin and gold, as they are alloyed together, they cannot be separated by heat of the two metals melting point, or by the metals density.

We can separate them by removing electrons from their atoms with acids, forming salts of the individual metals, (acid + metal = salt) and use the solubility of these salts of metals in solutions to separate them, as a chloride salt, the gold chloride salt is soluble in water, lead chloride salt is not soluble in cold water.

Before you loose valuable gold to experimenting, trying to melt your gold fill, try heating 50/50 solder see if you can make the tin and lead separate by temperature control or melting point of one of the metals, try again to see if you will be able to separate them by density, see if you can melt atoms from one of the group of the metal atoms and not the other, I can tell you it will not work

Now try acids separating tin and lead and separate the two, tin is soluble as a chloride lead chloride is insoluble.

The solder is an alloy and is no longer lead and tin but a new metal alloy composed of lead and tin atoms with different properties than the pure metals atoms used to form the alloy had.

Just as a ring can be an alloy of karat gold, composed of copper and gold, or a mixture of these metal atoms, with a new alloy melting point than either copper or pure gold has.


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## 24CaratHeaven (Nov 5, 2012)

So understanding what your saying, How do they refine 9ct gold back to pure..? Surely all these places are not just using acids ?


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## Lou (Nov 5, 2012)

At some point in the process, an acid must be used.


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## qst42know (Nov 5, 2012)

Being in the UK, a melt and assay may be all that is required to sell based on PM content. 

I'm sure Nick mentioned this before but I don't know if it applies to such low grade material.

Kinda takes all the fun out of it. :mrgreen:


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## martyn111 (Nov 5, 2012)

qst42know said:


> a melt and assay may be all that is required to sell based on PM content.




Sounds like that is what the buyer is doing.

24CaratHeaven, where in the UK are you located?


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## nickvc (Nov 6, 2012)

Many companies here in the UK just melt and assay or xrf the bars and ship to refiners as for them it's not worth the cost to set up a refinery. If the people you sell your scrap to are big buyers they will have a good deal with one of the big refiners and your rolled gold will just be added to the rest of their scrap and shipped out. 
One advantage we have in the UK is the access to fast cheap assays the other is that any hallmarked item will be as denoted, ie 9 k will be 0.375 gold, unlike our friends in the US where been under assay is allowed, this makes the grey area here less easy to exploit.
As the guys are telling you melting alone will not change the fineness of the metals to any noticeable extent and acids will at some point be employed to refine them, if you read C.M.Hoke which is free of many members signature lines it will give you the basics of how this is done and it's written for the layman not the chemist.


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## MysticColby (Nov 6, 2012)

even if you deliver previously melted bars, they will probably remelt them anyways to ensure you aren't trying to pull a fast one.


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## 24CaratHeaven (Nov 7, 2012)

[youtube]http://www.youtube.com/watch?v=EaxSaA5zfjg[/youtube]

I guess this is what they are doing...


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## MysticColby (Nov 7, 2012)

shorts and no face mask. not a great idea


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