# purple precipitation



## igrith (Jun 22, 2013)

hi people,
May you please help me out.i used nitric acid to remove gold from circuit boards. i took the washed gold leaf and the inert power from the circuit boards and dissolved the gold in aqua regia, adding nitric acid, drop at a time, until the gold was gone. I then added some deionized water and filtered in through an buchner to loose the board powder. i let it settle and then tipped the clear solution off. when adding smb, i got a purple precipitate. A gold compound? does anyone recognize this mistake? 
I was getting a white precipitate once, though i figured this to be excess nitric acid, burning smb? correct?

Any help would be massively appreciated. sorry if this is a repeat Q, though, i have been searching for a good while and cannot find it. 

thanks


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## Palladium (Jun 22, 2013)

igrith said:


> i have been searching for a good while and cannot find it.
> 
> thanks







> Joined: Sat Jun 22, 2013 3:51 am






:?:


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## AUH-R (Jun 22, 2013)

Palladium said:


> igrith said:
> 
> 
> > i have been searching for a good while and cannot find it.
> ...



that did make me laugh!! sorry for laughing at your expense igrith, but you have to agree.


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## glondor (Jun 22, 2013)

Search " colloidal gold" and " Metastanic acid" and "Stannous chloride" Report your findings and we can discuss once you have read up on these.


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## Pantherlikher (Jun 22, 2013)

Uumm... Hello.
What you really need to do is cover everything and safely store it and then come back here and read the welcome and safety sections. 
You do NOT use nitric acid to depopulate gold from PC boards. Then, "washed"? the gold? how?
Next...added water and let settle? Then tipped off the "clear water?
What you have done is poured off some of the gold you disolved in the Aqua Regia (AR)
Please store everything and read through this forum!!! Find Hoke's book and read that...It's free here.

Hope you do as I, we, all should have said, and learn about what you wish to accomplish. 

B.S.
...Learn to walk before attempting to run... It's safer that way...


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## necromancer (Jun 22, 2013)

glondor said:


> Search " colloidal gold" and " Metastanic acid" and "Stannous chloride" Report your findings and we can discuss once you have read up on these.




dont forget to set the timer, you may spend to much time searching.

purple will be the 27 second key word


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## Smack (Jun 22, 2013)

igrith said:


> does anyone recognize this mistake?




I do :|


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## Jbboswell703 (Feb 21, 2019)

In my lab, I produce a purple gold hydroxide salt in the following;

Au2+H2O+NaCl+HCl(31.45%)+H2O2 ---->
AuCl+NaCl+H2O+Chloride vapor

Then, administering lye solution (1/8 NaHO/H2O)

AuCl+NaHO+NaCl+H2O----->
AuHO+NaCl

The vivid purple, one can assume, correlates to the nanoparticle size of the molecule containing gold.


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## Lino1406 (Feb 21, 2019)

Nano-Gold


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## anachronism (Feb 22, 2019)

Thanks Lino that's really useful.

Jon


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