I added too much nitric acid. Everything went into solution

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Andyhaynes

Member
Joined
Feb 20, 2018
Messages
9
I am a newb for sure. I added too much nitric acid to the aqua Regia. Everything went into solution. It created a very dark liquid. I added a little sulfuric acid to try to get the silver and lead out and filtered it out. I added more fingers until I saw some of the gold leaf floating. I assumed I had added enough material in solution. I then filtered out the remaining materials. And added SMB and left it for several days. The liquid is green and what I think is silver chloride crystals on the bottom. I checked the solution before adding smb with stanous chloride and it showed gold. After smb I’m not getting any sign. Can anyone help?

Thanks
Andy
 
Andyhaynes said:
I am a newb for sure. I added too much nitric acid to the aqua Regia. Everything went into solution.
Well, that's the idea with aqua regia. It puts everything into solution. Why do you say you added too much nitric (you may have)? But is it because it put everything into solution? If that's not what you wanted to happen, what were you trying to do?

It created a very dark liquid. I added a little sulfuric acid to try to get the silver and lead out and filtered it out.
We use sulfuric acid to precipitate lead. We dilute aqua regia to precipitate any silver that might be in solution.

I added more fingers until I saw some of the gold leaf floating. I assumed I had added enough material in solution.
Was that your starting material for this batch? Fingers in aqua regia?

I then filtered out the remaining materials. And added SMB and left it for several days. The liquid is green and what I think is silver chloride crystals on the bottom. I checked the solution before adding smb with stanous chloride and it showed gold. After smb I’m not getting any sign.
How much weight in fingers? How much aqua regia did you use? How much SMB did you add?

Dave
 
Excess hno3 in aqua regia solution may cause several problems.when you try to precipitate gold(if you have gold in the solution) using SMB,the gold wil redissolve as fast as they precipitate.You can use sulfamic acid to kill excess hno3 in your solution before try to precipitating gold.Do search in this forum.There is many post that explain about how to precipitating gold in AR with right ways.

Sent from my ASUS_Z008D using Tapatalk
 
I used over 1000g of various items fingers, processors and a couple tria circuit boards, 4000ml beaker, 2500ml HCL, and im not sure how much stock solution nitric. All metals were dissolved which I did expect. I've watched youtube videos to get my info on this. I think I know enough to be dangerous. LOL! I thought it would be straight forward, yeah right. after all the metal was dissolved I added a little sulfuric acid and filtered got a little bit of substance filtered out. Then added the SMB, It precipitated something, at the time I thought it was gold, but when I decanted it was gray crystals at the bottom. The liquid is a clear green, I cant get any indication of gold using stannous chloride. I could before I added the SMB. I have no clue what to do now. Could having too much nitric be causing this issue? Im I able to add pic to see?
 
Here are some pics

Thanks for the help
F4153BD2-23E8-41D8-8D57-68E72D9AB6B6.jpeg
This is after smb and decanting and added water

1C872703-F5F1-458F-9A8C-A98183CCF8C4.jpeg
This is after it settled

7A5DB05B-B7AE-4903-994E-0F7D40E1FD06.jpeg
This is after adding water

F8355B06-F0D3-4FF1-AE4A-6377FF036A35.jpeg
This is after adding smb
140B5A04-2DBE-4441-95A2-CEF853852547.jpeg
This is at the beginning of the process. Sorry for the order I’m doing this from my phone
 
Joko sulistyo said:
Excess hno3 in aqua regia solution may cause several problems.when you try to precipitate gold(if you have gold in the solution) using SMB,the gold wil redissolve as fast as they precipitate.You can use sulfamic acid to kill excess hno3 in your solution before try to precipitating gold.Do search in this forum.There is many post that explain about how to precipitating gold in AR with right ways.

Sent from my ASUS_Z008D using Tapatalk
Thank you for the reply. I'll try the sulfamic acid to kill nitric

Andy
 
I understand now.You trying to dissolving everything in aqua regia and then recover gold from the solution?Youl will have much contaminants that will make your gold recovery process harder.That's bad idea for recovery of gold.Better you separate your source.finger,processor,gold plated pin,and board need different methods to recover gold from them.In this forum you can learn everything about recovery and refinery process for gold and other precious metals.Don't try as gold recovery videos on youtube without knowledge of chemicals or it will be high risk.Learn here.Be smart,be safe.

Sent from my ASUS_Z008D using Tapatalk
 
Thank you. I’m am familiar with the chemicals I have about 10. Grand in college chemistry courses. However they don’t really teach this kind of skill. So what do you think I should do at this point. There should be a good bit of gold somewhere.
 
Andyhaynes said:
So what do you think I should do at this point. There should be a good bit of gold somewhere.
My advice would be to loosely cover everything and put it aside while you study the forum.

You've already learned the first lesson, which is that things are not as simple as they look on youtube. Most new members come here looking for a quick answer to their simple questions, like "what should I do next?". Refining is too complex to hand out those quick answers without putting someone at risk. This forum is primarily a self-help resource. You'll have to devote the time to study the forum to learn the answers. Take a look at the Simple Answers thread to see what I mean.

Your gold, which I wouldn't expect to be a lot, could be in one of three places; the solution, the sediment, or the material that remained after you threw it all into the acid. I don't expect it to be in the solution. Since you say you had a positive stannous test before adding the SMB, I don't think you had too much nitric since that interferes with the stannous test, but since we didn't see the test result I could be wrong. Part of it could be in the sediment, and if you had a positive stannous test it may be. Part of it could also be with the bits of circuit boards and processors that did not dissolve, as gold that dissolved may have cemented out on undissolved bits of metal on those parts.

As you study, you'll find there are ways of dealing with each possibility. I provided some study strategies in the Tips for Navigating and Posting on the Forum thread. Best of luck.

Dave
 
Dave is right. As always.

Andyhaynes said:
What kind of yield is there for a pound of ram fingers?
1 to 2g, although I have read a bit lower and a bit higher, but, everything on the internet should be taken with a grain of salt and fact checked. Afterall, only your results matter.


If stannous is saying there is no gold, it is either because it isnt in solution(which means its mixed in with the gray crystals) or there is too much nitric still and it is reoxidizing the test result..

The solution could maybe be successfully treated with sulfamic (assuming the gold is in it and its needed), but, cementing on copper is better for the position you are in, Afterall its the next step if sulfamic fails, so just do it instead.

...yeah, I would do that.
Decant, add solid coppet and an air bubbler to that.

The crystals, id try removing with hot water, if that doesnt work, HCl. If the gold is in that mess, you will see it.

Do some searches here of
*stock pot
*cementing
*made a mess
*harold wash procedure

And about 10000 other things! :)

Dave still gave better advice (cover it and put it up while you study)
 
Thank you guys so much. I am reading as we speak. I’ll try the sulfamic acid. Just to see. Are the flat packs on the ram worth the trouble?
 
Seriously, I wouldn't even bother with Sulfamic at this point, you are just adding more chemicals into the soup. Single replacement reaction on Copper, aka Cementing on copper bar is the way to go now. Add a small amount of heat (40 deg C or so) and the cementing is very fast.

Then you end up with everything as powders which will need to be re-refined and a known barren waste solution which you then also have to deal with.

Also, what looks like a lot of Gold is only going to be a few grams best case scenario.
 
Sulfamic acid is used if you have too much nitric left after dissolving gold in aqua regia. You add it before filtering the gold solution as it might precipitate any lead still in solution. Then filtering and precipitating the gold. Sulfamic is not needed after the gold has been precipitated, unless you still have nitric acid left and your gold keeps dissolving when you add smb.

Gray or white crystals created when mixing SMB with a concentrated solution with a lot of copper chloride is often copper(I) chloride. It's easily dissolved with HCl. I ran into this problem early in my refining career. :D
http://goldrefiningforum.com/phpBB3/viewtopic.php?f=49&t=4008

Putting circuit boards in aqua regia can be a big loss of gold. The dissolved gold might cement onto the buried traces on multi-layer boards. I discovered this just in time before I threw it away. I still have that piece and some day I will clean it up to recover the cemented gold.
http://goldrefiningforum.com/phpBB3/viewtopic.php?f=60&t=17697

Göran
 
Where did this come from? I don't remember writing that.
Andyhaynes said:
So you suggest putting everything back into a beaker and heated it up to make everything fall out

Just keep it separated, labelled and loosely capped so no pressure is building up and keep studying until you know what to do with the material. When you have learned to test and treat the waste you could always test the liquid and if it doesn't contain any values then you can dispose of it in a responsible way.
The gold isn't going anywhere and cleaning up a mess is a good way to learn some basic skills.

Göran
 
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