# smb turning brown



## redneckdude (Jul 17, 2013)

hey guys my smb drop turned brown, and I hope I just didn't screw away my gold drop. if I have then crap. can anybody give some advice to what this is. it was the ap method on gold fingers. thank you for your time.

from your favorite kid in the crane, steve.


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## MEANIE (Jul 17, 2013)

psssst steve remove the bad words please

MEANIE


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## kkmonte (Jul 17, 2013)

lol, let the brown powder in the solution settle and that is your gold.


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## Charles Connor (Jul 17, 2013)

Did you dissolve your gold in AR and dennoxed it well before adding the SMB? Because it is for droping the gold down from AR... It would help a lot if you describe your process well to get certain suggestions...


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## redneckdude (Jul 22, 2013)

sorry for the swear word I was just upset. please forgive me. it turns out that my gold dropped successfully. again I apologize to the owners of this forum.


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## redneckdude (Jul 22, 2013)

no I used the acid and Clorox method.


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## NobleMetalWorks (Jul 22, 2013)

Charles Connor said:


> Did you dissolve your gold in AR and dennoxed it well before adding the SMB? Because it is for droping the gold down from AR... It would help a lot if you describe your process well to get certain suggestions...



You should not need to "denox" your solution. If you end up needing to you have not properly made additions of what you were using as an oxidizer, you have used too much. Making small additions of nitric acid if using AR, or making small additions of Cl in an HCl/Cl solution will negate the need to denox anything.

To the OP, if you have a nice chocolate brown color, relax and take a deep breath, that's your gold and exactly what you should be seeing. After it dries it should take on a tan color and will start to look like the pictures you have probably seen on this forum.

Scott


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## Geo (Jul 23, 2013)

when overzealous beginners first try aqua regia (and even people who have done it for awhile) they tend to add more nitric acid than they should. this causes the solution to have free nitric acid when the process is finished. it is difficult if not impossible to get the gold to precipitate without the free nitric reacting with the new metal and putting it back into solution. to say that you need to de-NOx a solution means you need to remove the free nitric acid (NO2, NOx) before you try to precipitate the gold. this free nitric will remain in solution for a very long time if not acted upon. 

acid+chlorine (hcl/Cl) is a work around method for people who have a hard time sourcing nitric acid. for beginners, it is more tolerant and forgiving. mistakes with additions are not so hard to fix. even though the chlorine gas is almost as bad as nitrogen dioxide (NOx), most people tend to handle it better. it works great for powders and foils. when the sodium hypochlorite (bleach, Cl) is added to hcl, it decomposes and releases chlorine gas. the chlorine gas is what dissolves the gold. once the reaction is over and the gold is dissolved, the chlorine gas will "gas off". the gas in solution is under pressure and will leave the solution without any further assistance. warming the solution speeds this up by forcing the gas out faster.

you can not denox a solution that never had a nitrate in it to begin with. you were de-chlorinating.

theoretically speaking, of coarse.


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## NobleMetalWorks (Jul 23, 2013)

hey Geo, thanks for making the distinction, I should have done so myself. Nice addition!

 

Scott


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## redneckdude (Jul 29, 2013)

thanks guys for the info. and again i apologize for the bad langauge.


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## Pruitt68 (May 17, 2021)

I added urea to nutralize then I added SMB and it would not stop boiling the entire solution began to thicken I then added all of that solution to another bowl of solution and it boiled little and stopped I now have entire solution as a dark brown color but sides of bowl are bright yellow I can't figure this thing out is there a place to take all my solution to see if they can percipate it for me


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## Lino1406 (May 17, 2021)

Give it some time. Show photo with bright yellow


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## Geo (May 18, 2021)

Stop doing things until you do figure it out. Every time you do something, it makes it harder to figure out what's gone wrong.


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## Iamdrainbows (Jun 12, 2021)

Charles Connor said:


> Did you dissolve your gold in AR and dennoxed it well before adding the SMB? Because it is for droping the gold down from AR... It would help a lot if you describe your process well to get certain suggestions...



I tried this. The gold was positive on a stannous chloride test. O added sulfamic acid and it turned negative. Does that mean it cemented on soe.thjng else


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## Geo (Jun 12, 2021)

Iamdrainbows said:


> Charles Connor said:
> 
> 
> > Did you dissolve your gold in AR and dennoxed it well before adding the SMB? Because it is for droping the gold down from AR... It would help a lot if you describe your process well to get certain suggestions...
> ...



Was there any other metal in the solution?


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## Iamdrainbows (Jun 12, 2021)

I'm not sure. I will need to test. I removed most of the magnetic stuff but there must be. I'm trying to cement the gold. Because it totally failed the acid test after the smb and the sulfamic acid 





Geo said:


> Iamdrainbows said:
> 
> 
> > Charles Connor said:
> ...


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## Geo (Jun 13, 2021)

If there is any copper in the solids, the gold can cement from solution before you have a chance to pour it in a filter. Keep leaching the solids until it doesn't give a color to the solution.


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## Hurc (May 11, 2022)

Geo said:


> If there is any copper in the solids, the gold can cement from solution before you have a chance to pour it in a filter. Keep leaching the solids until it doesn't give a color to the solution.


Hi
I need some help regarding gold precipetation by SMB. I try to extract gold from electronic components. I follow the following steps.
1 Crush the components
2: ) leach in dilited nitric acid to remove base metals.
3 Instead of aqua regia I used HCL & H2O2 IN 3:1 ratio for dissolving gold.
4 Step #3 gives green solution.
5 Due to lack of knowledge I used urea. It dissolved in solution. 
6 After dilution of step 5 solution I added SMB in powder form to my solution.
7 Solution colour change from green to brown as shown in pic. Is this colour seems to be gold? Because solution is brown but it is transparent. Some white powder settles down in solition. 
8 One more thing please as I put SMB powder in solution some of its particles turns to brown instantly and remain on surface for few seconds than dissolved.
You can see there are too many bubbles as well in solution.

Kindly guide me. Am I going in right direction and Is it gold or some thing else.
Thanks 
HURC


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## Yggdrasil (May 11, 2022)

Hurc said:


> Hi
> I need some help regarding gold precipetation by SMB. I try to extract gold from electronic components. I follow the following steps.
> 1 Crush the components
> 2: ) leach in dilited nitric acid to remove base metals.
> ...


Do not use Nitric to leach base metals in electronics. Tin from the solder will create meta stannic acid which is very hard to filter.
This description seems a little unclear. 
What did you leach and why.
Whole boards?
To remove components, foils or what?
The same goes for Peroxide as Nitric add just a little at the time until all you are dissolving has dissolved.
Peroxide do not create issues later though.
Why add Urea at all, but even more when there are no Nitric.
Why dilute it, when there can be no Silver?
The color do not look like gold to me, it is usually more a dirty brownish black and less reddish like this.
Did you test it with Stannous?
Why do you expect to have gold in it?
There is many unclear things here?
If you give us more information we might help you.
But first and foremost start reading C.M Hokes book and search the forum.


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## Hurc (May 11, 2022)

Answers for you questions.

What did you leach and why.
Whole boards?
I leach transistors for gold. Transistors of type as in attached image.

To remove components, foils or what?
Answered above.

Why dilute it, when there can be no Silver?
That is my inexperience. I will not do that in future. Infact I thaught by diluting PH will increase which might help in precipitating the gold by SMB.

Did you test it with Stannous?
No. I have stanous chloride salt. I will follow HOKES to make testing solution from it.

Why do you expect to have gold in it?
I am just checking that weather it has or not. You will confirm weather it has gold or not. Image is attached of the item I am processing.


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## Geo (May 11, 2022)

Per the photo above, these have very, very little gold by overall weight. In the package are only two bonding wires. Only a percentage of those will be gold bond wires and others will be copper or aluminium. I normally mix them in with random IC chips just to dispose of them. By themselves, they are not worth the time, fuel or chemicals to refine.


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## Hurc (May 11, 2022)

Geo said:


> Per the photo above, these have very, very little gold by overall weight. In the package are only two bonding wires. Only a percentage of those will be gold bond wires and others will be copper or aluminium. I normally mix them in with random IC chips just to dispose of them. By themselves, they are not worth the time, fuel or chemicals to refine.


Thanks Geo. I will upload some more electronic components tomorrow to know whether they worth to process for gold or not. Hopefully you will guide me.
Thanks


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## Yggdrasil (May 11, 2022)

Ok.
How did you treat these prior to leaching?
There may or may not be a couple of gold bonding wires inside.

Edit:
Geo beat me to it


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## Hurc (May 12, 2022)

Hurc said:


> Thanks Geo. I will upload some more electronic components tomorrow to know whether they worth to process for gold or not. Hopefully you will guide me.
> Thanks


Attached are the other electronic components. Namely these are resistors, Capacitor and mlcc ceramics. Can some one tell? Does these items contain gold or other precious metals or not?


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## Hurc (May 12, 2022)

Yggdrasil said:


> Ok.
> How did you treat these prior to leaching?
> There may or may not be a couple of gold bonding wires inside.
> 
> ...


First I treat the sample with sulfuric acid before leaching. Well attached are the pic of solution after 24 hours of smb addition. I also attached the image of precipitate I am able to separate from this solution.


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## Geo (May 12, 2022)

Hurc said:


> Attached are the other electronic components. Namely these are resistors, Capacitor and mlcc ceramics. Can some one tell? Does these items contain gold or other precious metals or not?


The left pic is aluminum foil/film capacitor. These are considered toxic waste with no PM value. The picture on the right are disc capacitors and are also considered MLCC. A certain percentage will contain silver and palladium. My friend Dusan has yield info and posted it on his youtube channel 999 dusan. https://www.youtube.com/c/999DusanGoldrecovery He has done a lot of experimenting with these types of components. I also consider him to be a good refiner. Keep in mind that he lives near Serbia and most of his scrap is ex-soviet hardware. He includes modern electronics that we all know.


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## Geo (May 12, 2022)

Hurc said:


> First I treat the sample with sulfuric acid before leaching. Well attached are the pic of solution after 24 hours of smb addition. I also attached the image of precipitate I am able to separate from this solution.


Roasting would be a better way of removing conformal coatings and remove leads. It doesn't involve any chemical waste. The coating converts to carbon and the carbon is converted to carbon dioxide in the presence of air at 800°F.


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## Yggdrasil (May 12, 2022)

Hurc said:


> First I treat the sample with sulfuric acid before leaching. Well attached are the pic of solution after 24 hours of smb addition. I also attached the image of precipitate I am able to separate from this solution.


Read Geo’s reply


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