-
Please join our new sister site dedicated to discussion of gold, silver, platinum, copper and palladium bar, coin, jewelry collecting/investing/storing/selling/buying. It would be greatly appreciated if you joined and help add a few new topics for new people to engage in.
Bullion.Forum
Extracting gold from gold filled Jewelry
- Thread starter Ian18206
- Start date
Help Support Gold Refining Forum:
cincyfriz, look up inquarting. It's an old and well known method of refining gold and has been used for 500 years.
If you use silver instead of copper it will save a lot acid and the silver is easily recovered, that will also remove some of the platinum group metals that inquarting with copper wouldn't get.
I guess that the main reason people using AR is purity and that it takes less acid. With AR you can separate Pt, Ir and so on too, there are a couple of other metals that resists nitric acid too that takes AR to get rid of.
For amateurs that have a hard time to get cheap nitric acid there are other workarounds to eliminate or minimize nitric usage.
Göran
If you use silver instead of copper it will save a lot acid and the silver is easily recovered, that will also remove some of the platinum group metals that inquarting with copper wouldn't get.
I guess that the main reason people using AR is purity and that it takes less acid. With AR you can separate Pt, Ir and so on too, there are a couple of other metals that resists nitric acid too that takes AR to get rid of.
For amateurs that have a hard time to get cheap nitric acid there are other workarounds to eliminate or minimize nitric usage.
Göran
Indian jewellers use the same method but I doubt you can achieve 9999 using just nitric,you can definitely get 99% + but if you sell on assay it matters not what exactly you gold percentage is.
99.99% on XRF... with what accuracy? +/-???%
To get four digits of precision it has to be a research grade machine at least. Handheld devices is probably a lot less accurate.
I did some digging and found two articles. The first one discussed precision versus accuracy. Really good read with a lot of graphics to explain that it isn't the same thing.
https://ndtlibrary.asnt.org/scholar/access/2017/AccuracyPrecisionandConfidenceinXrayFluorescenceforPositiveMaterialIdentification.pdf
Then I found this article that compared the accuracy between different gold assay methods.
http://www.folioinstruments.com/faq/faq%20oxford/real%20word%20accuraracy%20of%20xrf.pdf
Göran
To get four digits of precision it has to be a research grade machine at least. Handheld devices is probably a lot less accurate.
I did some digging and found two articles. The first one discussed precision versus accuracy. Really good read with a lot of graphics to explain that it isn't the same thing.
https://ndtlibrary.asnt.org/scholar/access/2017/AccuracyPrecisionandConfidenceinXrayFluorescenceforPositiveMaterialIdentification.pdf
Then I found this article that compared the accuracy between different gold assay methods.
http://www.folioinstruments.com/faq/faq%20oxford/real%20word%20accuraracy%20of%20xrf.pdf
Göran
upcyclist
Well-known member
I thought I'd point out that this is a thread on gold-filled jewelry, not karat jewelry.cincyfriz said:
As Goran pointed out, inquarting is the way to go. I wanted to call step #2 insexting, but 100g 14K to 500g Cu is even less than that--more like indecimating?
Topher_osAUrus
Well-known member
Maybe "incredibly unnecessary".upcyclist said:
And, of course, you are right that this is a goldfilled thread, but! (Wait for it)
Maybe!
Maybe That's why he posted it here, because he is taking the gold content to new lows of standard practice. What's goldfilled's gold content (allegedly), 2.5%?(hah! If you're lucky)
So maybe that is the puzzle piece thats missing. Or maybe Im just a donkey('s expletive).
But, I do think it is very unfrugal to use copper, and use so much of it.
If thats the knowledge being sold on ebay...Well, I guess they should have bought from Ralph instead
:shock: :shock: :shock:Topher_osAUrus said:
:lol:
Topher_osAUrus
Well-known member
Just sayin!
If members insist on using copper to refine then why not simply make it a 95% + copper alloy and use a copper cell to do the recovery for you, that way you get pure copper and slimes with the values in.
Now that's frugal
Now that's frugal
upcyclist
Well-known member
Better yet, don't refine it, just sell it as shakudo and call it a day! :lol:nickvc said:If members insist on using copper to refine then why not simply make it a 95% + copper alloy and use a copper cell to do the recovery for you, that way you get pure copper and slimes with the values in.
Now that's frugal
If your gold is reading .9999 on your XRF after inquarting with copper and parting in nitric, I suggest you replace your XRF! If you had said .995 it may be believable, but you still have a lot of copper laden waste to get rid of and ammoniacal waste. Too much wasted copper, and stinky ammonia!
I have taught many small jewelers going back over 30 years to inquart in silver and part with nitric to recover .995+ gold to recycle back into new jewelry. The major contaminant is silver which they likely will be adding to the new alloy anyway so no issue. The difference is they added silver as many have advised you. Your acid usage will be 1/3 of the acid usage if you inquart with copper and there will be no need to use ammonia washes. And, this should go without saying, you recover all of the silver that you added plus what was in the original alloy.
Welcome to the forum cincyfriz, if you are already doing some refining and own an XRF your experiences and contributions will be welcomed here. But there are some things you learn on the internet that are not the best ways to go about refining, here on GRF they are quickly exposed and debated. In essence bad techniques are exposed for what they are and everyone benefits. Again, welcome!
FlimsySloth
New member
- Joined
- Sep 27, 2017
- Messages
- 4
This post is helpful especially for a newbie like me, heads up to advisors here.
twhittaker67
Member
- Joined
- Jun 18, 2017
- Messages
- 6
My issue with AR is it's strength. I learned the hard way as a beginner that it dissolves the gold, steel, brass, and most metals in the jewelry, A beginner might find oneself self with gold in solution alright, along with every other metal in the piece. This leaves one having to precipitate lead, and other metals out before one can precipitate out the gold with SMB. That was my first try, I am sure I made many other mistakes as an amateur chemist. I finally recovered my two ounces of silver and a few grams of gold but it was long process that turned me off the whole thing for about a year.
I am almost ready to try again but I wonder if gold filled coating can be removed by reverse electrolysis like gold plating? It seem far less labor and chemical intensive. Any suggestions would be welcomed.
I am almost ready to try again but I wonder if gold filled coating can be removed by reverse electrolysis like gold plating? It seem far less labor and chemical intensive. Any suggestions would be welcomed.
When processing gold filled especially used material it needs to be incinerated first to remove any grease and dirt, after that you usually use nitric to remove as much base metal as possible but after that a further incineration and a Hcl wash will help remove any tin and more base metals, after that then go for whatever reactants you want to use as you are dealing with foils or powders which dissolve fairly readily.
You could strip the karat gold off but you will need cyanide not something I would advise unless you fully understand it’s dangers and how to use safely for you, your family, neighbours and the environment.
You could strip the karat gold off but you will need cyanide not something I would advise unless you fully understand it’s dangers and how to use safely for you, your family, neighbours and the environment.
Im new to pm long story short i put 500 grams of gold filled pocket watches in a beaker covered with water and adding 100ml of nitric acid at a time .reaction is good and i did it for about 2 hrs and decided to quit till the next day. I think a bunch of silver chloride formed at the bottom and some watch parts are cementing this chloride. My question is can i resume or is this cement going to cause a problem and if it does how do i fix that or proceed.
rickbb
Well-known member
I've only processed GF once, but my understanding is that using nitric will not create silver chloride, as dilute nitric will digest silver and hold it in solution.
Rrosetl, do not double post. I deleted your other post since it was nearly identical to this one.
I agree with rickbb. Since you did not mention adding any chloride, there should be no reason for silver chloride to have formed.
Dave
I agree with rickbb. Since you did not mention adding any chloride, there should be no reason for silver chloride to have formed.
Dave
Ok that kinda helps then what is the white powder at the bottom of the beaker and on some of the watch parts should i filter all white powder and hit it with hcl to see it disolves in that and keep filtering till it is gone or any suggestions would help thanks for answering post
nonono
If you are using tap water, it COULD be AgCl if you are on city water. But AgCl does NOT dissolve in HCl to any appreciable degree, and adding HCl to your nitric is a bad idea as it's going to make the gold very difficult to recover.
It could also be Ag that precipitated out, if you had insufficient nitric acid to digest all of the base metals.
If you are using tap water, it COULD be AgCl if you are on city water. But AgCl does NOT dissolve in HCl to any appreciable degree, and adding HCl to your nitric is a bad idea as it's going to make the gold very difficult to recover.
It could also be Ag that precipitated out, if you had insufficient nitric acid to digest all of the base metals.
