Best method to refine large amounts of GF jewelry?

[brywil1970]

I have refined a few small batches of GF jewelry using nitric and HCL in the past. I do have a BA in Chemistry. I want to refine larger quantities and I am wondering if anyone has any advise on best methods

 

[Yggdrasil]

I have refined a few small batches of GF jewelry using nitric and HCL in the past. I do have a BA in Chemistry. I want to refine larger quantities and I am wondering if anyone has any advise on best methods

Welcome to us.
Using AR directly will fast become expensive and create too much waste that need treating.
I think most use a preliminary leach in Nitric , HCl or Cupric chloride and then shakes loose/remove the foils and refine them after.
If this is practical in larger terms I do not know.
What is larger quantities in your book?

 

[Yggdrasil]

I have refined a few small batches of GF jewelry using nitric and HCL in the past. I do have a BA in Chemistry. I want to refine larger quantities and I am wondering if anyone has any advise on best methods

Here are some links worth studying:
Pay spacial attention to the Waste treatment and safety parts.

We ask our new members to do 3 things.
1. Read C.M. Hokes book on refining jewelers scrap, it gives an easy introduction to the most important chemistry regarding refining.
It is free here on the forum: https://goldrefiningforum.com/phpBB3/viewtopic.php?f=54&t=19798
2. Then read the safety section of the forum: https://goldrefiningforum.com/forums/safety.47/
3. And then read about "Dealing with waste" in the forum: https://goldrefiningforum.com/threads/dealing-with-waste.10539/

Suggested reading:
https://goldrefiningforum.com/forums/the-library.101/
https://goldrefiningforum.com/threads/when-in-doubt-cement-it-out.30236/
https://goldrefiningforum.com/threa...le-read-this-before-you-post-about-ore.33333/


Forum rules is here.
https://goldrefiningforum.com/threads/gold-refining-forum-rules.31182/

 

[brywil1970]

Welcome to us.
Using AR directly will fast become expensive and create too much waste that need treating.
I think most use a preliminary leach in Nitric , HCl or Cupric chloride and then shakes loose/remove the foils and refine them after.
If this is practical in larger terms I do not know.
What is larger quantities in your book?

I am thinking of doing it by at least a pound at a time. I have two 5 gallon buckets full

 

[brywil1970]

Here are some links worth studying:
Pay spacial attention to the Waste treatment and safety parts.

We ask our new members to do 3 things.
1. Read C.M. Hokes book on refining jewelers scrap, it gives an easy introduction to the most important chemistry regarding refining.
It is free here on the forum: https://goldrefiningforum.com/phpBB3/viewtopic.php?f=54&t=19798
2. Then read the safety section of the forum: https://goldrefiningforum.com/forums/safety.47/
3. And then read about "Dealing with waste" in the forum: https://goldrefiningforum.com/threads/dealing-with-waste.10539/

Suggested reading:
https://goldrefiningforum.com/forums/the-library.101/
https://goldrefiningforum.com/threads/when-in-doubt-cement-it-out.30236/
https://goldrefiningforum.com/threa...le-read-this-before-you-post-about-ore.33333/


Forum rules is here.
https://goldrefiningforum.com/threads/gold-refining-forum-rules.31182/

I am 1/2 way through the Hokes book. I know the safety aspects. Thanks

 

[4metals]

Another option is to melt the entire lot and bubble oxygen through the melt which will leave the copper and the precious metals in the crucible and oxidize out zinc and possibly nickel. Then it is a great candidate for a small copper cell. You won't get the values until you process the slimes but it is a method that is versatile and not out of reach for someone with a chemistry background and an inexpensive gas melt furnace. That of course assumes the pounds of gold filled keep rolling in.

I have done this on a large scale, but I know @Shark has done it on a smaller scale, maybe not with gold filled but with other scrap benefiting from smelting. If you are interested I am quite sure Shark will share his experience.

 

[brywil1970]

Another option is to melt the entire lot and bubble oxygen through the melt which will leave the copper and the precious metals in the crucible and oxidize out zinc and possibly nickel. Then it is a great candidate for a small copper cell. You won't get the values until you process the slimes but it is a method that is versatile and not out of reach for someone with a chemistry background and an inexpensive gas melt furnace. That of course assumes the pounds of gold filled keep rolling in.

I have done this on a large scale, but I know @Shark has done it on a smaller scale, maybe not with gold filled but with other scrap benefiting from smelting. If you are interested I am quite sure Shark will share his experience.

Do you have any information regarding the process of bubbling oxygen through the melt? I have looked into the electrolysis process, but have not seen anything about bubbling the oxygen through the melt

 

[4metals]

https://goldrefiningforum.com/threads/smelting.25592/

This thread about smelting describes the process. It is very similar to smelting circuit board metallics to get the base metals into
the slag leaving the copper and precious metals behind for electrolysis.