Need Help Refining Small Ring

[Rchrygy]

Howdy folks -

More of a smith/jeweller here than a refiner, but I am at a loss. I've made a wedding band for my wife a while ago out of gold mined from a friend's claim, and gold from a family heirloom. However, the ring is just a hair too rosy (too much copper combined with a little too much zinc to dilute the yellow of the gold, I believe) and I would like to extract the gold to remake the ring. Obviously the gold used is special and has great sentimental value for the both of us.

But I am at a loss. I do not have access to the space required or materials/tools to adequately and safely extract/refine the gold out of this ring. I have done much research on it, and it does not seem feasible in my situation. Of course most jewellers do not extract gold, only reshape it into different jewelry, and a small handful of the refining places I have seen either will not accept it, or have not responded in 3+ months.

Does anyone here know of any business or notable/reputable individual that could extract this gold for me? I am not concerned about the other metals in the alloy of course, those are easily replacable. Any help is much appreciated my friends.

Hey nickvc. I am a new member to this forum and am quite befuddled by the technical banter that frequents these postings. I was a jewelry teacher/craftsman for 35 years and am a typical right-brained artist. The pat answer I see here is to read C M Hoke book and go from there but I not only had a hard time finding the book online (I'm pretty computer illiterate) but the amount of information overwhelmed me. Here's what helped me the most.

I found my best source of information was utube videos, especially the STREETIPS series. The problem is that I had no ready access to nitric acid, which is relatively expensive and not readily available. Go to a thrift store or Goodwill and look for glass coffee pots and pyrex containers. Avoid corning ware. Then I researched some nitric acid substitutes and how to use them, and that's what I used (quite successfully). The trouble is that I can't recover the silver using sodium nitrate, though there is probably a process for that. I have not been able to find much info on this forum pertaining to these substitutes (but again, I'm computer illiterate).

Anyway, for the amount of gold you want to recover, I would explore the HNO3 substitutes. They are relatively inexpensive and easy to use. You can buy small kits on ebay. HCL can be found at any paint store or better hardware store's. The process is not all that hard but do it outside. You would have the assurance that you are refining your own gold that way and you can create your own alloy from there. I think Dave's comments are especially pertinent to your situation. Apologies for taking so much space.

 

[jeremys]

Thank you for this info!

Would these oxides be too much for the addition of borax to extract when melting?

I think you could easily get away with remelting it one more time. Pickle it first, keep borax on it, dont get it too hot, and use a reducing flame.

If you end up with troublesome inclusions that cause the metel to crack easily when rolling it out, then you can refine it. But try the easy thing first.
Besides, even if you refine it, you'll have to go through the process of melting the alloy together and if you are having trouble with gaining inclusions without refining first, you will probably still have problems introducing alloying fine materials.

As for the malibility, the change won't be significant. Alloy it to yellow it up but keep it 14k and find a recipe for the color you want. Just make sure you pick one designed for rolling instead of casting.

A standard 14k yellow gold made for rolling would be 28%Cu, 7% Ag, 7%Zn. This is close to what you report but the zinc has a big impact on making it more yellow.

A brighter yellow would be 30%Cu, 3.8% Ag, 7%Zn.

 

[jeremys]

Edit: removed text from accidental double post

 

[FrugalRefiner]

Hey nickvc. I am a new member to this forum and am quite befuddled by the technical banter that frequents these postings. I was a jewelry teacher/craftsman for 35 years and am a typical right-brained artist. The pat answer I see here is to read C M Hoke book and go from there but I not only had a hard time finding the book online (I'm pretty computer illiterate) but the amount of information overwhelmed me. Here's what helped me the most.

Rchrygy, there are links to Hoke's book in my signature line at the bottom of all my posts.

When you see terms you don't understand, take a look in A Glossary of Common Terms.

Dave

 

[Alondro]

That is about what I figured. If it were much more volume, I am sure it would be a different story.

Right now my alloy is 58.3% Au (2g), 29% Cu (.98g), 8% Ag (.27g), and 4.7% Zn (.16) for a band at 3.41g.

My concern is this is approximately 14k, as was selected for the best durability. Would diluting it by adding more Au and Ag (albeit making the color more yellow) make it too malleable?

That's a small ring, indeed. You'd need only maybe 10 mls of aqua regia to dissolve it completely (leaving some solid silver chloride in there too). 3 to 4 grams is about the size of the first refine I ever did, with scrap jewelry, and it only used a large 20ml glass test tube to hold the reaction.

For such a small ring, I'd start with 8 mls of conc HCl, then add conc nitric drop by drop, allowing it to react a while before adding the next drop, until the ring is dissolved. Then denox with a couple drops of sulfamic, filter the solution, then wash filter with hot distilled water a few times (adding washes to the solution), and drop the gold from filtered solution with a small amount of SMB... hmm, for such a small amount, maybe about a teaspoon of SMB powder (roughly 4 grams of SMB)

 

[Rchrygy]

Rchrygy, there are links to Hoke's book in my signature line at the bottom of all my posts.

When you see terms you don't understand, take a look in A Glossary of Common Terms.

Dave

Thanks so much. I'll try to wade through it. It's hard to turn off that right-brain sometimes but I'm motivated in this case. Thanks again.

 

[FrugalRefiner]

You are right, her book is kind of a slog the first time through. Everything is new and you'll be lucky to absorb a small amount. Then read some more on the forum. Then read her book again. More will make sense. I've read it cover to cover at least a half dozen times. I've learned new things every time.

I've been a member here for over twelve years and I still learn new things all the time. This is an extensive study. No one knows it all.

Dave

 

[Chief]

As the op is a jeweller and probably has access to rolls couldn’t he add copper to his alloy then roll it very thin and then use AP which is easy for most to make ?

I do indeed have a rolling mill. What does this process entail?

 

[Chief]

All -

Thank you so much for all of this information and helpful advice! I surely did not expect so much help in such a short time as I am not usually a forum lurker.

I will attempt to add to my alloy first as that is what I have the materials and experience to do safely, and see if that will correct the color adequately. Should that not work as intended, or as mentioned if there is too much oxidization, I will revisit attempting to refine it myself with some of the methods posted.

Thank you all again and I will hopefully have a favorable update soon!