Gold and Copper in Solution

[AndreTrollip]

Hi Guys,

I am making my first attempt at extracting and refining gold. I have dissolved my gold in aqua regia, but I fear I may have also dissolved a lot of copper along with it because my solution is a deep green color.

So having made this mistake, I need some expert advice to try and get the gold out.

Can I still use SMB to drop the gold out? And do I still need to neutralize the solution with urea before adding the SMB?

Any help would be appreciated.

 

[AndreTrollip]

I found this thread that seems to be about a similar problem.

http://goldrefiningforum.com/phpBB3/viewtopic.php?f=49&t=24074&p=254708&hilit=Copper+in+Aqua+regia#p254708

I think I will rather use copper to cement out the gold if I don't find a better solution.

 

[4metals]

Either option would work for you. It is good that you are reading. You should also read about ways to minimize your nitric usage so you will have no need to "kill" the excess.

If you have a lot of solution, I would choose copper, if it is a small quantity, I would dilute it with cold water and add metabisulfite.

And, as usual, always test all solutions with stannous chloride.

 

[AndreTrollip]

Thank you 4metals. Appreciate the reply.

 

[goldsilverpro]

It's poor procedure to try and dissolve gold away from copper with aqua regia. The copper wants to dissolve the copper first. When some gold does dissolve and there's still copper undissolved, the gold tends to precipitate (cement) back onto the copper in the form of a fine black powder. If you want to dissolve all of the gold, it's usually necessary to dissolve all of the copper.

With gold plating on copper, there are 3 basic approaches
1 - Strip the gold away from the copper without attacking the copper. On the forum, this is most commonly done with a strong sulfuric acid used electrolytically. Professionally, a cyanide solution is normally used
2 - Dissolve all the copper, leaving the gold undissolved. Then, the gold is dissolved by itself, using a small amount of aqua regia. Initially, the copper is dissolved with nitric acid/water or with the AP process, Muriatic acid/hydrogen peroxide (or, better, an air bubbler)
3 - Dissolve everything with aqua regia More difficult to drop the gold with SMB because of the large amounts of base metals present. For the same reason, the gold dropped will be quite dirty.

 

[kernels]

I did a similar thing a while ago, evaporated down to get rid of nitric, then dropped gold out with SMB, my solution ended up a nice blue color. Then simply re-refine the gold powder at least once more. The nice thing was that because I started the second refining process with powder, it was easy to get the nitric close to spot on, and also used barely any acid.

 

[Behind The Scenes]

At least this thread wasn't everyone bashing eachother. Good job guys..

 

[Yggdrasil]

At least this thread wasn't everyone bashing eachother. Good job guys..

I am puzzled.
Commenting on 8 year old threads adding nothing of value.
What is your goal with your stay here?

 

[galenrog]

I am puzzled.
Commenting on 8 year old threads adding nothing of value.
What is your goal with your stay here?

Agreed.

Time for more coffee.

 

[Behind The Scenes]

i am the unsilent MAJORITY...

 

[Yggdrasil]

i am the unsilent MAJORITY...

You have not made much out of anything including answering questions.
And as a single voice, you certainly are no majority.

So please humor us and state your business here.
So far you have made no sense, not to me anyway.

 

[Behind The Scenes]

All i see on this thread are people bashing beginers for trying things " we were all there" I am A PHD from America that came across your thread while i was refining. I couldnt believe when someone asks a question how to do something it turns into a pissing match instead of helping the guy out. thats it in a nutshell. You arogant jerk.

 

[FrugalRefiner]

We don't address each other that way here.

Thanks for visiting. You are banned.

Dave

 

[galenrog]

I doubt that Behind the Scenes will have learned anything from his short stay, but when any established member asks a question, please answer. More so if a moderator or administrator asks the question.

Also, a PHD is only impressive if used to improve yourself.

Time for more coffee.

 

[nickvc]

To those mew members reading this thread please be aware all the mods and most members will try to help but if new members do not listen or do the necessary reading that help evaporates quickly, no one here is paid and the help is given freely costing members time and effort , we are not perfect but we try our hardest to make members welcome and unfortunately we get the odd supposedly educated member who wants to stir things up for some supposed insult to some unknown set of members.
We do not and cannot hold anyone’s hand through the processes but just about every process is fully covered on many threads hence the advice to read and if you still have a question then post it and you will get an answer.

 

[4metals]

A PhD, or a doctorate of philosophy, is properly identified as PhD, not PHD. Somehow I expected someone having earned that level of expertise to know this.

 

[ssmontecarlo]

Wow...been awhile since I've been on the forum...one thing I've learned. Be polite to members....

 

[Shark]

I have known a few people with a PhD, and everyone of them were/are more than willing to share their knowledge. Not one had that kind of attitude.

Also, a PHD is only impressive if used to improve yourself.

Well said!

 

[Yggdrasil]

I'm not entirely convinced that all the ones bragging about degrees actually have them.
Some seem to lack the qualities needed.
But what do I know, I have no PhD

 

[Martijn]

All i see on this thread are people bashing beginers for trying things " we were all there" I am A PHD from America that came across your thread while i was refining. I couldnt believe when someone asks a question how to do something it turns into a pissing match instead of helping the guy out. thats it in a nutshell. You arogant jerk.

I bet your stay will be short if you keep this up. I would expect better from someone with a phd...