# Gold recovery



## pierrejulien52 (Nov 13, 2017)

Hi, i have dissolved a mix of gold, copper, nickel and iron with a mix of hcl and h2o2
The solution is green.
The solution is free of cl2 but There is an excess of h2o2.
How do i precipitate gold without dragging iron and other material.
I have about 250 liters of thé solution.
Thank you very much for your support.


----------



## nickvc (Nov 13, 2017)

You have a lot of solution there and unless you have a considerable amount of gold in solution getting it to settle after precipitation could take forever, to recover your gold simply cement out with copper and then redissolve but use more caution with the peroxide, that way you have a much more concentrated solution of gold which is much easier to precipitate and settle.


----------



## Topher_osAUrus (Nov 13, 2017)

That is a ridiculous amount of solution.

But, unless I missed something......

Its peroxide... It will decompose to water and oxygen.
Do yourseld a favor. Heat up the solution. Evaporate some of the water, then reduce the gold thats in it. The best way is how nick suggested, cementing on copper. Assuming there is gold in it..
What did stannous testing show?


----------



## pierrejulien52 (Nov 13, 2017)

Thank you very much for both of you, when you say cement with copper, what does it mean


----------



## nickvc (Nov 13, 2017)

If you do not understand the meaning of cementation then you really shouldn’t be dissolving metals in vast quantities of acids.
Cementation means to displace metals lower in reactivity with metals higher, precious metals are all lower reactive than base metals.


----------



## niks neims (Nov 13, 2017)

pierrejulien52 said:


> I have about 250 liters of thé solution



Sorry man but something doesn't add up... Maybe you made some mistake regarding quantity in your original post? Did you dissolve metals yourself? What Did you dissolve and how much acids were used exactly? Maybe you dilluted everything with water? Or maybe you have a wast expirience and i am missing something? BUT If you mean to tell me that for your first aquaintance experiment you used >200l HCl.... How?


----------



## jimdoc (Nov 13, 2017)

He is probably working on a pile of rocks.


----------



## niks neims (Nov 13, 2017)

jimdoc said:


> He is probably working on a pile of rocks.



hey, maybe you are right! I just kinda assumed that material in question is e-scrap, i did not know that "AP"-type method can be used on ore... 

also :


pierrejulien52 said:


> gold, copper, nickel and iron


Sounds awful lot like a PCB  and if the original quantity is correct then could this be the tell-tale of a guy who put a truckload of whole PCBs in to a vat of acid...now that would really be "fun" story to read... let`s hope OP will chime in soon...


----------



## FrugalRefiner (Nov 13, 2017)

pierrejulien52 said:


> Thank you very much for both of you, when you say cement with copper, what does it mean


When you see terms you don't recognize, you can find many of them in A Glossary of Common Terms in the Library section of the forum.

Dave


----------



## pierrejulien52 (Nov 13, 2017)

Hi, i dissolved 100kg of ram in mix of hcl and 30% peroxyde.
I miscalculate the formula and i used too much peroxyde


----------



## pierrejulien52 (Nov 13, 2017)

I made mistake, i have about 175 liters of solution


----------



## niks neims (Nov 13, 2017)

pierrejulien52 said:


> I made mistake, i have about 175 liters of solution




i was kind of hoping that you ment 2.5l or at most 25l... still less is better 

if you don`t mind my asking - is this your first expirience with gold recovery from e-waste?


----------



## pierrejulien52 (Nov 13, 2017)

No, it is not my first time. My problem is i started Big instead of small. I thought it Was simple, but i realise that a lot of things can happened and you have To understand everything before you start.
Like copper chloride 1 and 2 and smb.
It is like a recipe, you have To know the ingredients .
Thank you


----------



## pierrejulien52 (Nov 13, 2017)

When you say cementation, is it the same things as to place copper in a silver nitrate solution. The copper is replace with silver.


----------



## niks neims (Nov 13, 2017)

anyhow i don`t think you`ll like cementing very much, if 100 kg RAM boards is all you did dissolve, then your "AP" is very unsaturated, very crudely and if I am not mistaken, the saturation ratio is about 4(kgHCl):1(KgCu) so to sucessfully cement out your values you will need more than 40 kg copper (minus some 20-30 kg from RAM you already dissolved)

what you should do is decide what will you do next with your copper (II) chloride (your "green liquid", "AP"), if you want to continue to work with it, then my advice is to use it on more material (just not whole boards!) until it nears saturation and then look to reclaim this gold (be careful, cemented gold doesn`t look like gold at all, also it can cement out inside the PCB)

if you don`t want to continue working with this solution, you shold study waste disposal so you can dispose of your acid safely, it will also probably involve cementation on copper or iron...

in any case, my friendly advice is that you should study much more before working with acids (and on much smaller scale), the method you are basically using goes by the name "Acid Peroxide", do a search on it... also, for example - you do know that most of the gold on RAM stick is inside Integrated circut chips, not on the fingers?


----------



## pierrejulien52 (Nov 13, 2017)

If i understand right, i have to place a piece of copper in the solution and some copper will be replace by gold.
I have To filter the solution and place the residus in aqua regia and precipitate.
Do i have to get rid of the h2o2 first or it does not matter if it is there.
Thank you for your time.


----------



## kernels (Nov 13, 2017)

You place solid copper into the solution and agitate continuously. Brown / Black powder will form on the copper and drop off into the solution. The copper will disappear as it goes into solution to replace the Gold. 

175L is a crazy amount of solution. 

No, the excess H2O2 will not matter.

As stated above, one of the problems is that your solution will eat very large amounts of Copper. You will need lots of Copper to make this work.

This is such a surprising post that I would have thought it a prank / troll if it were not for the serious tone of your posts.


----------



## kernels (Nov 13, 2017)

To give you some idea, I have processed a similar amount of material over the last year and ended up with around 10L of waste acid to treat.


----------



## pierrejulien52 (Nov 13, 2017)

Does the pins on the ic chips made with iron, nickel and manganese or iron, copper and manganese 
Thank you


----------



## kernels (Nov 13, 2017)

Some are Kovar (iron) and some are Copper based. Did you put the entire RAM module(s) in the acid ?


----------



## Lino1406 (Nov 13, 2017)

I suggest to take 1 liter solution to make pilot experiment


----------



## g_axelsson (Nov 14, 2017)

What Lino said... and *what did the stannous test say*?

Göran


----------



## Topher_osAUrus (Nov 14, 2017)

g_axelsson said:


> ...and *what did the stannous test say*?
> 
> Göran



What kind of test is that? And who is this Stan Nous guy, and what makes his testing so infallible :?: .. :?


----------



## pierrejulien52 (Nov 15, 2017)

Thank you.
Yes i put the entire ram boards with hcl and h2o2. 
Could you tell me how sensitive is stannous chloride.
Could i détect 0.1 gram of gold per liter of solution.


----------



## jimdoc (Nov 15, 2017)

http://goldrefiningforum.com/phpBB3/viewtopic.php?f=41&t=25072&p=265525&hilit=sensitive+is+stannous+chloride#p265525


----------



## pierrejulien52 (Nov 17, 2017)

Hi, for the cementation, does anyone know the relation between gold and copper.
If i have 50g of gold in gold chloride how much copper do i need To displace the gold.
Thank you very much for your help.


----------



## pierrejulien52 (Nov 17, 2017)

Does anyone know where To buy scrap ram in large quantité 100kg+
Thank you


----------



## richoc (Nov 22, 2017)

Did all your gold flake go in to solution because of to hot a mix.
If not, are just looking to get the rest of the metal out of the solution?


----------

