Help on smelting gold foils

[razvanflorin]

Hi everybody !
I have a question about gold smelting..

I do have a friend that directly smelt gold foils recovered from pins and he got the purity of 22k-24k .. How is this possible ? He is just smelt the foils but i didn't know what kind of flux is using.. i have seen a Little bit of blue slag on one of his button.. Does Anyone have any idea or suggestion ?

P.S. he didn't wanna tell me how he do this..

 

[goldsilverpro]

The gold foils are not pure in most cases. To purify the gold, it is best to dissolve the foils in aqua regia and precipitate the pure gold with something like SMB. It's easier to dissolve the foils, as is, than to dissolve them after they are melted. Also, it eliminates the extra step of melting. Also, there's no way to purify the gold in the melt. It has to be done chemically.

 

[kernels]

Yep, as above, it's no big deal to just melt the foils if that is what you want to do, a little bit of borax once the foils start to melt would work fine. If the foils going in were 22k to 24k then the button coming out will be 22k to 24k.

The biggest problem I see is that there is always a lot of little bits of fibreglass and 'crap' when you filter your solution to recover you foils, refining the gold allows you to filter out this crap easily, not sure how you would remove it if you melted the foils directly.

 

[nickvc]

Your friend is doing a recovery and isn't refining, that's fine if he gets what he wants, if you want high grade gold then refining is a must, if he sell his buttons on then I bet they short change him because there is no way to be sure of its purity that's the one advantage to refining if done correctly you know exactly what percentage you are getting paoid.
As for anything but metals going into the melt it doesn't matter they will simply burn off, just make sure the foils sure rinsed well and you have no chloride salts in the melt or loses will occur.

 

[razvanflorin]

I have heared from him something about amalgama , what's this ?

 

[goldsilverpro]

No No. You certainly don't to amalgamate the gold with mercury. You are much better off keeping your foils away from your friend.

 

[jason_recliner]

I have heared from him something about amalgama , what's this ?

• More hazardous
• More difficult to recover
• A bad idea

 

[razvanflorin]

Yesterday he have melted some of my foils and got 3.8 grams and a purity of 95℅ of gold, a very good result in my opinion ..

That's how the crucible looks like after he melted the gold foils .. What's the blue slag inside ? Are he using amalgama or he just sayd that to make me more confuse ?
He sayd that the blue slag is borax but how would the borax slag Be blue ? I think he is using a different kind of flux...

Any idea ?

 

[patnor1011]

Blue slag mean you do have impure gold. Copper and nickel probably and they colored your slag blue. If pure gold is melted slag should be with only a hint of violet/pink.

 

[razvanflorin]

Yea.. But the gold purity was 95℅

 

[Topher_osAUrus]

Yea.. But the gold purity was 95℅

Pure gold vs 95% gold is night and day difference.

And it looks like alot of your gold is still in the crucible.

Maybe your "friend" is taking you for a ride?

 

[razvanflorin]

Yea.. But the gold purity was 95℅

Pure gold vs 95% gold is night and day difference.

And it looks like alot of your gold is still in the crucible.

Maybe your "friend" is taking you for a ride?

There are about 0.2 gr of gold in the crucible, the result was good and the remained slag is mine so i can recover IT. i just wanna know how do he get's that purity of 95% i have melted some gold foils by my self and i have got a purity of 48% and a very big lost of the quantity...
I sayd that he is my friend but He is my uncle and is 56 years old, he have a very good experience . he didn't wanna tell me how he do it because he sayd is too dangerous. The problem is that i just wanna know for my information but he didn't wanna' talk about.
If it will Be too dangerous for me i will didn't do IT but i must know !!

 

[Topher_osAUrus]

Yea.. But the gold purity was 95℅

Pure gold vs 95% gold is night and day difference.

And it looks like alot of your gold is still in the crucible.

Maybe your "friend" is taking you for a ride?

There are about 0.2 gr of gold in the crucible, the result was good and the remained slag is mine so i can recover IT. i just wanna know how do he get's that purity of 95% i have melted some gold foils by my self and i have got a purity of 48% and a very big lost of the quantity...
I sayd that he is my friend but He is my uncle and is 56 years old, he have a very good experience . he didn't wanna tell me how he do it because he sayd is too dangerous. The problem is that i just wanna know for my information but he didn't wanna' talk about.
If it will Be too dangerous for me i will didn't do IT but i must know !!

What were the foils from? The time that they came out 48% when you melted them?

That seems strange to me, as I was under the impression all gold plating used in electronics is of 95%+ so, that if your foils had all of the base metal removed that they were plated on, they would come up to be high % gold, just not quite "fine gold" or 24k pure. For that purity they need chemical dissolution.

Thats a very blue dish. Very blue. Reminds me of Prussian Blue almost. -just a random thought

I dont know if we will ever be able to get you your answer by guessing? I think your uncle may be the only man able to give you a glimpse into his gold methods.

Hope you get it figured out though. Im getting more and more curious.

 

[razvanflorin]

Yea.. But the gold purity was 95℅

Pure gold vs 95% gold is night and day difference.

And it looks like alot of your gold is still in the crucible.

Maybe your "friend" is taking you for a ride?

There are about 0.2 gr of gold in the crucible, the result was good and the remained slag is mine so i can recover IT. i just wanna know how do he get's that purity of 95% i have melted some gold foils by my self and i have got a purity of 48% and a very big lost of the quantity...
I sayd that he is my friend but He is my uncle and is 56 years old, he have a very good experience . he didn't wanna tell me how he do it because he sayd is too dangerous. The problem is that i just wanna know for my information but he didn't wanna' talk about.
If it will Be too dangerous for me i will didn't do IT but i must know !!

What were the foils from? The time that they came out 48% when you melted them?

That seems strange to me, as I was under the impression all gold plating used in electronics is of 95%+ so, that if your foils had all of the base metal removed that they were plated on, they would come up to be high % gold, just not quite "fine gold" or 24k pure. For that purity they need chemical dissolution.

Thats a very blue dish. Very blue. Reminds me of Prussian Blue almost. -just a random thought

I dont know if we will ever be able to get you your answer by guessing? I think your uncle may be the only man able to give you a glimpse into his gold methods.

Hope you get it figured out though. Im getting more and more curious.

the button that i got from the foils that i smelted was 48 ℅ Gold, 28 % Tin and the rest was copper . those that he smelted was almost the same, there was tin and a Little bit of copper inside of the foils, but he still got it as 95% . one more thing, he's telling me everytime, bring it to me wet ( inside water ) not dry !
If anyone had any idea.. Please answer here..

And about Amalgama (mercury and gold) i have seen on google an distilation system for Mercury that will separate the Mercury and left behind the gold, in my oppinion it's looks simple, i know that everytime is harder than it's looks. If someone have the knowledge and the pleasure to explain me that method i would Be glad to hear him.

Thanks to everyone for the answers !

 

[Topher_osAUrus]

So how are you getting just the foils?

I would think with AP or chemical means the majority of tin woild be eliminated.

Are you just cutting them off with a razor blade?

I would stay away from mercury and just read up on Copper (II) Chloride method on here. Then dealing with waste. Then HCl + Bleach. They are safer than amalgamation and a good thing to learn so you can get more money for your precious metals.

Each of those 3 topics have more than enough information on the forum so you can get a great understanding of them. Also Hoke's book is what should be read first, twice.

After all that, I'm more than certain your uncle would be asking you *your* "tricks" .. Which are nothing more than common practice to todays refiners.

Best of luck

 

[razvanflorin]

So how are you getting just the foils?

I would think with AP or chemical means the majority of tin woild be eliminated.

Are you just cutting them off with a razor blade?

I would stay away from mercury and just read up on Copper (II) Chloride method on here. Then dealing with waste. Then HCl + Bleach. They are safer than amalgamation and a good thing to learn so you can get more money for your precious metals.

Each of those 3 topics have more than enough information on the forum so you can get a great understanding of them. Also Hoke's book is what should be read first, twice.

After all that, I'm more than certain your uncle would be asking you *your* "tricks" .. Which are nothing more than common practice to todays refiners.

Best of luck

I have used nitric Acid but Most of the tin have stuck in the filter, i have removed a part of the tin in decanting and filtering inside a stainless steel filter, but i still got tin inside the foils . i didn't think that Mercury is that dangerous , when i was a child i have cracked an thermometer and played with the mercury and nothing happened to me, but maybe i was lucky. I will search for an Mercury msds.

 

[patnor1011]

He is simply washing his foils better, perhaps that is why his purity is higher. Maybe he is smelting them with lead and then use cupelation. Or maybe he is just making a joke.
Leave mercury be, if you cant successfully process simple foils to have them better than 48% you do not have chance to use mercury properly. And besides it is not advisable old and dangerous method nobody use anymore. It is only used in some poor countries to recover flour gold which is again different than foils from electronics.

 

[goldsilverpro]

i never worried about the tin. I would just use aqua regia on the foils, tin or no tin. The tin can then be filtered out and then rinsed well with hot water. You probably don't realize this but, you most likely know more than your friend, who obviously doesn't know anything about scrap (ore, maybe), just by being here a few days. I would suggest that you control the outline of the process.

 

[razvanflorin]

Well.. Thank you all for your help, support and answers :mrgreen:
I will forgott about the Mercury proccess.
But.. the AR Process is still looking too complicated for me.
I will try this way:
1. Put the material in the HNO3 Solution and wait for base metal to dissolve.
2. Decant all the HNO3 Solution and add a fresh HNO3 Over the remained Gold Foils to dissolve any possible copper remained.
3. After the HNO3 Solution will have no reaction i will decant, add hot water , filter as much as possible.
4. I Will take the remained gold foils that still contains a little bit of TIN and maybe some traces of HNO3 rinse, wash them as much as possible and put them in a stainless steel vessel and incinerate on the hot plate, after the metastannic acid ( tin ) will incinerate and become a TIN OXIDE i will soak them in hcl and boil(swimmer) after this i will wash them good decant ,filter and dry then i will melt them as usual.
5. i will take the hcl solution that i have boiled the gold foils in and i will test it with stannous chloride for any traces of dissolved gold.

if someone has any suggestion on melting the gold foils please leave a comment below ! :idea: :mrgreen:

Thanks you all !

 

[FrugalRefiner]

if someone has any suggestion on smelting the gold foils please leave a comment below ! :idea: :mrgreen:

Razvan, you are not smelting your foils. You are simply melting them.

When you heat a metal until it changes from a solid to a liquid, you are melting, just like heating an ice cube till it melts.

Smelting also uses heat, and any metals become liquid, but it also involves fluxes that cause the material to undergo chemical changes. Smelting may be used to process ore concentrates, circuit boards, MLCCs, etc.

Dave