# Aqua Regia - Green solution (base metal removal?)



## domperignon (Sep 11, 2013)

Good afternoon,

I have a problem and I was wondering if i can get some help, (First time) 

I had made up 2 solutions of HCL to dissolve the base metals on some PCB's and old pins that i had collected, the other to was the Gold plated CPU's (lucky enough had been given 10 Intel Pentium Pro old ones!).

After washing the CPU's and purifying them of base metals, I decanted the fluid and proceeded to make a A/R solution to which i added my CPU's (fine i believe).

Heres the problem I added the PCB and the gold pins directly into the A/R and completely forgot the wash and left overnight (what a plonker). 

Woke up this morning with a Dark green cloudy liquid, to which I was mortified as it was not as i expected, I filtered immediately and witnessed the gold had been removed from the CPU's and hopefully dissolved into the A/R 

I believe Base metals have been dissolved into the solution (i.e copper,lead and alu) as it is DARK GREEN not a beautiful Yellow/Gold liquid.

Alas my query from here how do I proceed, I have been scouring this forum for the last day and have read parts of HOKE and cannot find a solution to my problem.

I can attach pictures and all help from all individuals will be greatly appreciated.

Thanks, 

Dominic

P.S - Not how I anticipated my first refining of gold.


----------



## maynman1751 (Sep 11, 2013)

Are you SURE that all base metal is dissolved? If not, your gold will have cemented out of solution. Have you tested the solution with stannous? You need to know where your gold is. Has it gone into solution or cemented out on the remaining base metals. More info needed.


----------



## 4metals (Sep 11, 2013)

You have not said one very important thing......." have tested with stannous chloride and found the gold to be in solution"
or possibly".............. I have tested with stannous chloride and the solution does not show gold"

If you failed to test you need much more assistance than you can imagine. 

Test your solutions and report back your results, you can recover the values you have dissolved but you need to give more information to get proper advice.


----------



## domperignon (Sep 11, 2013)

Good evening,

Yes i did forget to mention the key stannous chloride test!

I have tested and yes gold is present in the liquid.

Any advice on furthering this?


----------



## butcher (Sep 12, 2013)

Dominic, 
A few things concern me, from what it sounds like you can have all kinds of metals in solution with your gold, you may also have gold plated onto base metals of the remaining materials, printed circuit boards and CPU's can have metals hidden like copper under layers, many circuit boards will have copper under the solder mask and many times between layers of the fiberglass, you could have gold plated up inside these areas where it is hard for acid to reach.

I cannot see what you are doing, but from what you describe, and they way I understand it, you have a mess, you are losing your gold.

Use copper to cement values from solution, test the solution and treat it for waste (read up on dealing with waste in the safety section).

Save the remaining solid material, rinse it dry it and store it in a safe place.
This includes not only the cemented powders but anything that originally went into the acids.
Such as circuit boards, metal from the pins, or remains of the CPU's

Read up on how to process your scrap mechanically, and suggested methods to process each type of scrap separately.

This was your first time and your first mistake, the best way to not repeat this mistake again is to spend your time studying, at first this all seems so simple, just remove some base metal in acids and use aqua regia to refine your gold, well it is not that simple, there are minor details at every turn that if you do not understand them you will have problems and lose gold at every turn.

Start with Hoke's after you read the book, go back and read it again, this time doing the getting acquaintance experiments, paying close attention to what you learn from these experiments.

I think you need a lot more time studying to learn how it is done, and less time trying things you are not completely sure how they are done or the reactions involved.

Believe it or not, studying and not working in the lab can be the fastest way to get your gold, where working in the lab without study is the best way to lose your gold.


----------



## bluebee (Jun 14, 2020)

Dear sir, 
My name is syed , I have done those process as follow...I took some ram Gold finger and Mobile boards and I do add hcl and nitric acid with water and it become dark green and I filtered solution and put urea to neutralize nitric and add SMB POWDER but no gold dust is there and the solution color is the same dark green. What i have to do sir. Please do let know,

Thank you sir


----------



## FrugalRefiner (Jun 14, 2020)

Bluebee, welcome to the forum. I deleted your other post since it was identical to this one and it didn't belong on the AP thread since what you've created was not AP. Please do not double post. Choose a section or a thread, make your post, then wait for replies.

You shouldn't mix different types of scrap like RAM fingers and phone boards in the same batch. It's possible that any gold you dissolved cemented back out of solution on undissolved metals on the phone boards.

What does a stannous chloride test of your solution tell you?

Dave


----------



## bluebee (Jun 15, 2020)

FrugalRefiner said:


> Bluebee, welcome to the forum. I deleted your other post since it was identical to this one and it didn't belong on the AP thread since what you've created was not AP. Please do not double post. Choose a section or a thread, make your post, then wait for replies.
> 
> You shouldn't mix different types of scrap like RAM fingers and phone boards in the same batch. It's possible that any gold you dissolved cemented back out of solution on undissolved metals on the phone boards.
> 
> ...



Yes, I tested with stannous chloride the solution is pregnant with gold, Please let me know, How to extract gold from the solution pls


----------



## FrugalRefiner (Jun 15, 2020)

My suggestion would be to cement the gold out with copper.

Dave


----------



## rickbb (Jun 15, 2020)

If no gold powder dropped then most likely you still have active nitric in solution. 

Which means you used to much nitric in the first place.

Don't use urea, use sulfamic acid, it works better.

Now about the phone boards, did you depopulate them, removing all components and remove any tin/lead solder first?

If not then you have made a mess and made it much harder to recover any gold. 

And how many ram/phone boards are we talking about? A few boards or a few pounds of boards?


----------



## bluebee (Jun 16, 2020)

FrugalRefiner said:


> My suggestion would be to cement the gold out with copper.
> 
> Dave



How to cement the gold out with copper? I am newbie,It's my first time in precipitation of gold


----------



## FrugalRefiner (Jun 16, 2020)

Place some heavy pieces of copper in the solution. Stir the solution from time to time. The copper will dissolve into the solution as the gold cements out.

Dave


----------



## bluebee (Jun 21, 2020)

rickbb said:


> If no gold powder dropped then most likely you still have active nitric in solution.
> 
> Which means you used to much nitric in the first place.
> 
> ...



Hi Rickbb,
Thanks for your reply and yes i used much nitric acid and second one is i did depopulate the pins and other extra parts but i did not remove chip and all.

I used around 50 mobiles and 50 rams as sample.
-------------------------------------------------------------------------------------------
and I did second try I took 10 ceramic processor and I add some nitric acid, The gold was extracted from processor and i took it, wash it few times and i melt it but i did not get any gold. Your advice will be valuable for me and let me know, How to neutralize nitric acide from gold dust


----------



## kuli (Oct 5, 2020)

Hi goldersss

I dont know now.. I get green solution too. On Hooks book they said put ammonia or coper to sokution.. What is important now... I read but dont understand...


----------



## kurtak (Oct 5, 2020)

kuli said:


> Hi goldersss
> 
> On Hooks book they said put --- ammonia --- to sokution..



Unless you actually KNOW what you are doing --- NEVER add ammonia to your solutions that have metals dissolved in the solution

In SOME cases you can end up making explosives by adding ammonia to a solution that has metals in it !!!

SOME of those explosive can be so sensitive that they can blow up in your face !!! 

Kurt


----------



## Martijn (Oct 5, 2020)

Hi, Dominic, understand what and why you're doing it. I sure don't understand why you have done things this way. (yes I do... gold fever and YouTube, I've been there too, most of us have) 

Don't pre-mix AR, just add HNO3 in small increments. 

HCL does not dissolve copper. AR does, that's why it turned green 

Dissolving plated pins to get the gold is like dissolving mount Everest to harvest the snow on top. Highly inefficient, and creating unnessecary large amounts of waste. ( I know, because I tried that too  :lol: )

How much material did you dissolve? There may not be enough gold there to even be visible with the naked eye if it were only a few boards and pins.

From all you have posted I understand one thing: you don't understand enough yet to be recovering, let alone refining.
study and ask qustions here. a link to get you started: https://www.goldrefiningforum.com/phpBB3/viewtopic.php?f=86&t=24397#p258067

*@ KULI:* to answer your question: "_What is important now... I read but dont understand_" stop experimenting and keep reading until you understand. 
DONT ADD AMMONIA TO AR! DONT USE UREA! ask us before you attempt anything.. 

Martijn.


----------

