water+ Nitric wash.. gold gone?

[RichWat123]

Hi.

Thanks for looking in advance ..

I have been processing gold from computer chips this last week..

Hydrochloric Acid 35.0-36.6% + Peroxide 3%... remove base leave gold fingers and/or leaf. toyed with 3/1 and 1/1. I am ok with that

I have toyed with just a Nitric Acid 69% wash and Nitric Acid 69% + water.

What I am looking for is a mild aqua regia (if there is such a thing) I can basically put everything else .. pins.. ide ends.. ram ports . to remove plating .. but without bringing the base into the solution .. I have tried Hydrochloric Acid 35.0-36.6% + pipet of Nitric Acid 69% so I can control the reaction.

Right all above said: I have some solution .. much the same as using 6% Peroxide that has dissolved the gold .. example today I put the filter and leaf straining in water + Nitric Acid 69% (3/1) thinking it would just break down the last bits and the filter .. but everything went into solution???

I have tried to drop it with Sodium Metabisulphite 97-100.5% I get the fizz the mixture has gone a strong urine colour and fizzy (sodium) to the nostrils and eyes .. but no drop... im doing a Stannous chloride test (negative or very very slow) but I know especially in the filters case there was gold but very little anyway.

I am reluctant to commit much more material till I get this process sorted ... I can remove fingers and process to completion .. I can Sulphuric Acid 96% Gpu and process to completion. I can melt jewelry and process to completion.

Its just a couple of times I have been left with 100ml of solution I know contains some gold but cannot process.

I currently have some copper suspended in the container to see if I can get it to cement

Any 'On point' advise would be appreciated

Thanks

 

[Topher_osAUrus]

It seems as if there was residual acid in your foils that ended up mixing with the nitric and dissolving the gold. So you have your gold now dissolved in a very strong AR. You could try to denox (remove free nitric from) the solution with sulfamic, but there is probably way too much oxidizer in it to be successful.

You have made a wise decision using copper to cement.

I am a little confused by part of your post though.
You are wanting a weak AR to remove the gold, but leave the base metals? Correct?

The reactivity series of metals will prevent you from achieving that goal, as the gold will quickly be replaced in the solution by the base metals, and instead of having foils that are relatively easy to deal with, it will be a fine black powder. Same concept and you cementing your gold on copper

If you want to switch between acids, you must thoroughly wash the first leach from the foils, and then incinerate to remove any traces of acid. Also, when using hydrochloric acid and hydrogen peroxide, a 1/1, even a 3/1 is far too much peroxide. It only requires a little bit to start the reaction, in fact, no peroxide is needed if you use an air bubbler in the HCl.

There are, however, a couple leach types that can selectively remove gold from base metals. But, they can only work with certain types of scrap. A sulfuric cell is one, and a cyanide leach is the other. Both are quite dangerous, and I suggest much (MUCH) study before attempting to use either one of them.

 

[RichWat123]

Hi,

Thanks for the reply.. I got to about page 5 of forum threads.

Yes, I can sit and pull jumper pins and dimm slots off boards .. sata sockets , but really I just want to bathe them (dip) I did experiment with a laptop board so most board fixings went into Hydrochloric Acid 35.0-36.6% then I put just 1 pipet of Nitric Acid 69%.. I understand where this might have gone wrong the gold has cemented back out ... I pulled stripped components so thought it had worked.

So what am I seeing when videos full of magnetic pins .. yellow solution .. drain off and pins remain stripped? (same for smashed cpus) .. ?

I put pins , sata plugs, sdcards , ide jumper pins , ide hd ends .. in water + Nitric Acid 69% (3/1) and this stripped most base (solution went blue) I recovered gold leaf by filtering .. some metal was left as well as gold (tea spoon amount of foils) .. so I put the lot including filter paper in Nitric Acid 69%.. everything went into solution .. water+nitric then nitric. shouldn't have dissolved gold ?? Stannous is negative and no solids and nothing to cement to? nothing

Hence binning and copper ...

Will need a solution for jumpers , ram sockets , cpu sockets (dip) to process my bulk items.

 

[kernels]

When you have made many mistakes and wrong assumptions, it is quite difficult to get you onto the right path without telling you to go read and study and to stop doing 'experiments'

Yes, I can sit and pull jumper pins and dimm slots off boards .. sata sockets , but really I just want to bathe them (dip) I did experiment with a laptop board so most board fixings went into Hydrochloric Acid 35.0-36.6% then I put just 1 pipet of Nitric Acid 69%.. I understand where this might have gone wrong the gold has cemented back out ... I pulled stripped components so thought it had worked.

Dropping entire boards or even entire connectors in acid is a bad idea, as clearly stated above,
base metals will always prefer to be in solution over precious metals. You can also have issues arise from the plastic, there is a really really good reason why people who do this separate the metals before any processing

So what am I seeing when videos full of magnetic pins .. yellow solution .. drain off and pins remain stripped? (same for smashed cpus) .. ?

The only way I can see that working is if a leach is used to dissolve gold from the pins,
if you link to a specific video we can give you a better explanation, but it just doesn't work like that.

I put pins , sata plugs, sdcards , ide jumper pins , ide hd ends .. in water + Nitric Acid 69% (3/1) and this stripped most base (solution went blue) I recovered gold leaf by filtering .. some metal was left as well as gold (tea spoon amount of foils) .. so I put the lot including filter paper in Nitric Acid 69%.. everything went into solution .. water+nitric then nitric. shouldn't have dissolved gold ?? Stannous is negative and no solids and nothing to cement to? nothing

Did you use distilled water ? Tap water can contain chlorine which will put gold into solution with Nitric Acid

Hence binning and copper ...

Sure, the copper will go into solution and the gold will cement out, 1 teaspoon of foils is a very very small amount of gold, it will probably just look like a brown coating on the copper

Will need a solution for jumpers , ram sockets , cpu sockets (dip) to process my bulk items.

This is a community helping each other, if you contribute and show that you have studied,
the members will be very helpful. The items you want to process are very very very low yield (crap), not good ewaste to learn with.

 

[Topher_osAUrus]

I was typing another reply on my computer, when I got busy, sorry. I will try to answer as best I can, but I believe there may be a language barrier and some things may be getting lost in translation.

... I did experiment with a laptop board so most board fixings went into Hydrochloric Acid 35.0-36.6% then I put just 1 pipet of Nitric Acid 69%.. I understand where this might have gone wrong the gold has cemented back out ... I pulled stripped components so thought it had worked.

As kernels stated, it is really best to remove components first, then remove base metals, and then finally put the gold into solution. Several base metals can cause endless headaches when they are dissolved with gold.

So what am I seeing when videos full of magnetic pins .. yellow solution .. drain off and pins remain stripped? (same for smashed cpus) .. ?
I'm going to guess that it isnt aqua regia, as that's just not how royal water works.

I put pins , sata plugs, sdcards , ide jumper pins , ide hd ends .. in water + Nitric Acid 69% (3/1) and this stripped most base (solution went blue) I recovered gold leaf by filtering .. some metal was left as well as gold (tea spoon amount of foils) .. so I put the lot including filter paper in Nitric Acid 69%.. everything went into solution .. water+nitric then nitric. shouldn't have dissolved gold ?? Stannous is negative and no solids and nothing to cement to? nothing

What other metals were left? A lot of them? You say you threw the filter paper in the next leach too, but yet no solids remain? While I have pulped filter paper in strongly acidic solutions, I have never had it vanish into nothingness. Intriguing....

I am not sure on tap water and nitric dissolving gold either, unless it has tons and tons of chlorides, I just dont think it would happen to any appreciable amount.. This I would like to know more about though, as it was mentioned in another thread recently too. I think if it dissolved any gold, it would be negligible at best. Harold used tap water for everything, always, (save his silver cell electrolyte), and he never seemed to have troubles with nitric eating away his gold. I would lean more towards traces of HCl ended up dissolving the foils and the base metals cemented the gold back out, and its so little, or so fine, that it is almost unable to be noticed, especially in the filter pulp mix.

Its very easy to get cross contamination between acids if one is not careful, and with you mentioning ap, then ar, then nitric... I just have a feeling that it was a bit of HCl.. But, I dont know... Hard to say without the whole step by step story..literally leaving out nothing. (someone asking for a gearbox recently, comes to mind..)

Hence binning and copper ...
binning? Like the trash bin??
Will need a solution for jumpers , ram sockets , cpu sockets (dip) to process my bulk items.

With more study of the forum, these methods you seek will come to you. They are here, but it will take 5 months or more to get all the information you need to be successful in this endeavour, not just 5 threads or 5 pages. This is a patient man's game.

 

[RichWat123]

Morning

Thanks for the replies ... Yes before starting I had been reading and watching for months...

Collecting materials and effectively creating my work space.

I know gold has gone into each process, when I say 'experiment' I mean each start to finish process be it to remove base and leave fingers ... or solution to remove gold flake from lcd boards .. I was looking for the results (whatever they may be) there had to be 1st time, I didnt commit too much product be that material or acid.

When I say 'Bin' I mean a tub with air stone + lid to save everything till I am happy.

Thanks for your input.

As I say I did have processes and mixtures thought out, now I have my fails and not so happy points to investigate .. like joining a forum.

 

[RichWat123]

Ok,

I have seen this happen again, I have a Nitric wash .. it was coloured blue from removing pins before ...

I had foils and bits that needed removing .. I guess incineration is the way to go...

Anyway, foils went into liquid ..

Q. is how to recover gold from a high Nitric concentrate solution.. Stannous chloride test is positive

I understand members saying read/find out .. but to get to this one detail I am rereading posts and sites and not getting 'The' answer.. So I joined a forum to ask

Cheers in advance

 

[nickvc]

The simplest way is to cement the gold out using s piece of copper, the gold may well look like a black powder so collect any sediment and wash the copper off to collect all you can, from there you can dissolve your gold by any method you choose.
I would advise to do a lot of reading and study it makes your and our lives a lot simpler and allows for a better understanding of what is discussed.

 

[FrugalRefiner]

Q. is how to recover gold from a high Nitric concentrate solution.. Stannous chloride test is positive

I would use that high nitric concentration solution to dissolve more foils from your next batch. You'll recover any gold that is already dissolved without wasting the nitric acid.

Dave

 

[kernels]

You could also stop and ask yourself why Nitric acid is dissolving the gold. Were these foils in contact with HCl at some point ? It sounds like you recovered the foils by dissolving the base metals away using dilute Nitric acid ?

What is the starting material ? How much of the starting material was there ? The plating on some connectors can be extremely thin, I can believe that these extremely thin gold pieces can dissolve in Nitric with only a whif of Chlorine about, especially if you have almost nothing to start with.

You really do not want to work with less than 1g of gold to start with, any less than that and it's not always obvious where the gold is. You could precipitate the gold from a solution and not even see anything happen.

To be targeting to work with 1g of gold, you need to start with at least a few kgs (or pounds) of pins from consumer PC motherboards. There is far less gold there than you think. I always recommend anyone new buy a few pounds of PC ram and start by processing the gold fingers, at least then there is a bit of gold to see.

Finally, there is a thread on here (search) entitled "Why can't I get a simple answer for a simple question" - http://goldrefiningforum.com/phpBB3...t+I+get+a+simple+answer+for+a+simple+question

 

[RichWat123]

Hiya,

Thanks for the replies. Left copper hanging in solution overnight and gold is on there today.

As above, I think I have uses too little gold in my initial tries at each process.

Thanks again.