# Other more common precipitants..



## Dr_Nayik (Feb 23, 2014)

Hello, 

i'm new on this forum and yes i have read hoke's book.. But.
I don't have copperas in SMB is not that cheap to buy here, so are there any more common precipitants to drop gold (and other metals) from AR i suppose the mixture is pretty clean of all impurities and if it weren't would it be possible to run the powder through nitric/sulphuric acid to remove all the remaining copper and other unworthy metals?

thanks
Have a nice day


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## nickvc (Feb 23, 2014)

There are methods describing how to make your own copperas by Butcher I believe that uses sulphuric acid and iron scrap failing that use the search function top right of your screen and look for precipitants.
Welcome to the forum and good luck.


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## Dr_Nayik (Feb 23, 2014)

I have also tried with aluminum foil, it created somewhat brown/blackish powder, i guess aluminum drops out everything?
Also would it be equally efficient if i use a stronger sulphuric acid to make copperas? Like 98% sulphuric acid or would that simply not work? I don't think i can dilute the sulphuric acid to exactly the concentration needed.
Thanks nickvc


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## bmgold2 (Feb 23, 2014)

Cementing the gold out of solution using copper would be a better choice than aluminum. In another post, Butcher states:



butcher said:


> I would avoid aluminum, it gets very messy, and can form a gelatinous compound which can easily trap values, the reaction with acid solutions can be violent as the hydrogen leaves the acid as hydrogen gas.
> Aluminum is also harder to deal with in treating the waste solutions.
> 
> I would choose copper or zinc depending on the goal.
> ...



Here's a link to one post where Butcher explains how he makes coperras in case you missed it.

http://goldrefiningforum.com/phpBB3/viewtopic.php?f=48&t=14026&hilit=copperas

I'll quote that message here:



butcher said:


> I could not find good copperas as my garden supply stores, the copperas came in bags and was always oxidized brown (which would not work to test for, or to precipitate gold with).
> 
> Copperas is easy for me to make, and when I do I make a big batch to last me for a while.
> 
> ...



You should be able to dilute your concentrated acid by just adding it to water. I'm not sure exactly how much water but you should be able to calculate it depending on the strength of your concentrated acid. Add the acid to the water slowly...DON'T ADD WATER TO ACID.

I was looking for a way to get the right percentage and still haven't found it but I did find this article http://www.ukessays.com/essays/chemistry/concentration-of-sulfuric-acid.php which states:



> When the concentration of sulfuric acid increase from 10% to 60%, the time is decreasing, in other words, the rate of the reaction keeps speeding up; but when the concentration of sulfuric acid reaches 70%, there's no reaction between iron and sulfuric acid at all! At first, I cannot even believe what I saw, so I repeat the reaction between iron and 70% sulfuric acid for several times but eventually lead to the same result: Nothing happened. Then I search this strange thing among a lot of books and websites, and this is called passivation2.



With that information, I'd say take 9 parts distilled water and slowly add 1 part of your concentrated sulfuric acid and you should be close enough. Maybe someone else will explain how to get 10% from 98% acid if I'm way off.


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## Dr_Nayik (Feb 23, 2014)

Wow thanks!
This will be really helpful, i have a batch of about 10 kg random circuit board from cellphones (should i submerge them fully in acid?), old rams, motherboards, CPU's, cellphone cards..
So i want to have a solid plan before i start going big

cheers


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## Geo (Feb 23, 2014)

http://goldrefiningforum.com/~goldrefi/phpBB3/viewtopic.php?f=37&t=17237

http://goldrefiningforum.com/~goldrefi/phpBB3/viewtopic.php?f=37&t=18753

http://goldrefiningforum.com/~goldrefi/phpBB3/viewtopic.php?f=37&t=6106

oxalic acid
SO2 gas
any more reactive metal
gold chelating compounds

if there are no impurities, raising the PH until the solution cant hold the metal salt will precipitate all metal in solution.


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## kurtak (Feb 23, 2014)

Dr_Nayik said:


> Wow thanks!
> This will be really helpful, i have a batch of about 10 kg random circuit board from cellphones (should i submerge them fully in acid?), old rams, motherboards, CPU's, cellphone cards..
> So i want to have a solid plan before i start going big
> 
> cheers



NO !!! Do Not just throw your circuit boards in acid - this does not work that way -The simple fact that you make this statement (what I underlined above) tells me you have not yet done the research that you need to in order to do this properly &/or safely

Please stop what ever you are doing & take some time to search & read this forum for the information you need to know before you even start --- this is not something you just jump into - you will at best end up with nothing but a big mess --- or worse end up hurting your self

This is not something you learn by watching a couple of YouTube videos or by reading a few pages of instruction or by asking a few questions & then jump in & start doing armed with only some information - it takes research - LOTs of research --- you need to know & understand the entire process - before you start - & even then - when you do start you are going to make mistakes - but at least then they will be small mistakes & you will then be able to explain what you did & ask the right kind of questions so that we can actually help you

Everything you need to know about doing this has been talked about many times over right here on this forum & most any problem you will run into is covered here before ---so start by searching - reading & studying this forum --- doing so will help us help you

I am not trying to be harsh with you - I am simply telling you the way it is --- we can not help you if you don't take the first step to help your self - which is to do some reading to start with in order to get a basic understanding to start with

Kurt


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## Dr_Nayik (Feb 23, 2014)

Thanks geo, i will check out those.
Kurtak, excuse me for improperly wording myself, by "acid" i meant nitric acid, when i tried it for the first time i dumped about 3 boards into it and let it do it's thing and just picked the foils of gold out to further reduce it from its base material.
I don't put everything in aqua regia, as it wouldn't do anything.
Again, excuse me for the incorrect wording.

Cheers


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## kurtak (Feb 23, 2014)

Dr_Nayik said:


> Wow thanks!
> This will be really helpful, i have a batch of about 10 kg random circuit board from cellphones (should i submerge them fully in acid?), old rams, motherboards, CPU's, cellphone cards..
> So i want to have a solid plan before i start going big
> 
> cheers



you do not put whole circuit boards in nitric acid - if that is your starting plan - you don't know enough to be starting - you need to start by reading & researching

You need to learn what you are doing before you start doing it

Again I am not try to be harsh with you - I am simply giving you good advise to help save you from making a lot of unneeded mistakes

Kurt


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