Properly botched job

[aga]

Being impatient, and to get a 'feel' for how things look at all stages in extracting & refining gold, i pressed ahead and dissolved everything from an old PC that contained gold in a weak AR.

All connectors and chips were dropped straight into AR.
Silly (if you actually want to get the gold) but done anyway to see what 'wrong' looks like and how it turns out.

The fingers from the ram sticks were lifted with the vinegar/salt process, washed, had any remaining base metals dissolved out with minimal nitric acid, then filtered and washed again before being dissolved in excess (~300ml) AR (probably only needed a few ml max).

The resulting liquids after filtering are :-

The nice one on the right is from the fingers, the other two just different types of sockets/chips.

Definitely an awful lot of copper in those, along with a tiny amount of gold.

Göran said some plastics can deform/degrade in the acids and end up trapping some gold.
This, of course, happened as foretold.

The acids were being used up at a high(er) rate due to all the base metals, so even with leaving the pots covered overnight, not all the metals in the connectors had dissolved:-

So far i've learned that 'doing it wrong' creates an unholy mess that will be very complicated to recover from, if it is even possible.

Also, the proper method(s) done badly (the fingers in a vast excess of acid) can give misleading results.
Despite being the nice golden yellow colour of chloroauric acid, that solution tests Negative with SC.
(strip of filter paper, dipped once, then a drop of SC added to one end).

After leaving the test strip for around 5 minutes, a very faint brown colour can be seen, whereas the other end of the strip remains white.

As to tracking 'where is the gold ?' that's easy - it's now in All of the pots, filter papers, funnel, waste plastic/ceramics etc !

Following a tried-and-trusted method and doing it right is clearly the only way to go if you want to end up with any gold at all, never mind 3-9's.

Gonna be a while figuring out how to get the gold back from the Nasty green & blue liquids.

Started by trying sodium bicarbonate and a few mls of the Green stuff to neutralise the acids and precipitate basic copper carbonate, hopefully removing the copper.
Didn't work : the carbonate forms a suspension and refuses to precipitate. It'd probably trap a lot of the gold anyway, even assuming that the gold doesn't co-precipitate with the copper.

Any pointers on what to do next would be awesome.

 

[jeneje]

Any pointers on what to do next would be awesome.

Study the forum and get a copy of Hoke's Book and read it.

Ken
edited: to say read my sig line, all three apply here.

 

[aga]

Certainly still reading lots of the forum and finding things out.

Line 3 of your sig is partly why i've gone ahead and deliberately 'botched' to see how it turns out.

The posts i've found so far show how things should look.
Now i know how they should Not look.

The tiny amount of gold in that PC is a small price to pay IMHO for that knowledge.

Already beginning to really appreciate much better how the Correct ways to process gold came about, and why certain procedures are followed to the letter.

For a first attempt at proper refining i'll snip a piece off a 1g .999 bar, weigh it, then process and attempt to recover as much of it as possible, then report the losses.

Need to at least try to recover the gold from those three beakers first, then render the liquids safe.

 

[g_axelsson]

I'm lucky I didn't drink something when reading this or I would have to replace my keyboard... hmm, that would allow me to refine it.

Where to start... at least you reached your goal of failing.

One thing...

The fingers from the ram sticks were lifted with the vinegar/salt process, washed, had any remaining base metals dissolved out with minimal nitric acid, then filtered and washed again before being dissolved in excess (~300ml) AR (probably only needed a few ml max).

Slight excess... usual rule of thumb is 1 ml nitric for each gram of gold and excess HCl, so 4-5 ml AR per gram of gold but those numbers are probably too high too, I did it with 0.65 ml nitric per gram of gold (using reflux).
So I agree, excess.

For the gold in AR, I suggest denoxing by evaporation to get the volume down, gives you opportunity to test that procedure too.
If you have sulfamic acid you could split the batch in two and compare the two methods.

So far I've learned that 'doing it wrong' creates an unholy mess that will be very complicated to recover from, if it is even possible.

I think it is possible, miners manage to drag a few grams from a ton of ore, but if it is economical to do it is another question.

For the stannous test, try letting a drop of solution dry out first, the add stannous. Any results? The oxidator is volatile and should just evaporate while the gold chloride remains.

Göran

 

[aga]

usual rule of thumb is 1 ml nitric for each gram of gold and excess HCl, so 4-5 ml AR per gram of gold but those numbers are probably too high too, I did it with 0.65 ml nitric per gram of gold (using reflux).

Awesome !

Even though i calculated it to be way overboard, i was working on the assumption that an excess of nitric versus HCl is needed, not the other way around.

For the gold in AR, I suggest denoxing by evaporation to get the volume down

That one did spring to mind. The yellow liquid will be boiled down tomorrow to see how it responds to stannous test at half the volume.

If you have sulfamic acid you could split the batch in two and compare the two methods.

DOH ! Yes i do, but that idea never occurred to me at all (blush).

For the stannous test, try letting a drop of solution dry out first, then add stannous.

That sounds good. I will try it before boiling the liquid(s) down.

Thank you very much for those Pearls of Wisdom !

It is information like this from people experienced in a specific process that beats pure theory-led chemistry every single time.

 

[FrugalRefiner]

For the gold in AR, I suggest denoxing by evaporation to get the volume down

That one did spring to mind. The yellow liquid will be boiled down tomorrow to see how it responds to stannous test at half the volume.

For the stannous test, try letting a drop of solution dry out first, then add stannous.

That sounds good. I will try it before boiling the liquid(s) down.

Evaporate, do not boil.

Dave

 

[g_axelsson]

And boiling in this case would be done in a lab set up with proper catching of the mist with a reflux? If you boil it in an open vessel some of the values will be carried out by the steam. I wrote evaporate, not boiling.

Read this thread. http://goldrefiningforum.com/phpBB3/viewtopic.php?f=37&t=11392

Göran

 

[aga]

Thank you for the corrections Dave and Göran.

Me saying 'boiling' was a case of Lazy typing.

The liquid contains HCl and HNO₃ so i'd never actually Boil it, knowing that both of the acids would come off/decompose as gasses.

Once i did produce/experience a very large cloud of HCl gas/vapour and choose never to replicate that, even on a small scale. Producing large uncontrolled volumes of NO_x is not an attractive idea at all.

The idea of reflux is interesting. Vapour-phase chloroauric acid ?

Edit:

Oh. I see from the link that it will go into vapour if boiled.

Further edit:

Looked up it's solubility in water, and it's Huge, so highly likely that any kind of heating will take gold out of the pot entrained with the water.

 

[Geo]

Sorry. I just can't see the trying to fail thing as being realistic. I like to look at things as possibilities and probabilities. Is it possible? Yes Is it probable? Probably not. There's nothing wrong with saying, hey, I messed up and followed some shady information and messed the whole thing up. It was months after joining the forum before I even tried AP. I didn't dissolve gold until a year after I joined. I'm not saying that testing isn't a good thing because it is. The problem is, how can you tell whether or not you failed unless you already know what to expect? If you have no idea what it's suppose to look like or how it's suppose to react, how do you know whether something worked or not. Be sure to study the process you want to try. Find out what is needed and how each thing is used. Study to see what each chemical is and how it reacts with the other chemicals and reagents. You should have a clear picture of the end result and what your expectations are. You can't throw a pile of electronics in a pot and gold bars come out the other side.

 

[jeneje]

You can't throw a pile of electronics in a pot and gold bars come out the other side.

Ummmmmmmm,,,, :shock: Are you sure about that?

Ken :mrgreen:

 

[Justincase]

Sorry. I just can't see the trying to fail thing as being realistic..

It could be a hole new form of Tax evasion.
Instead of the supper rich having to go to the trouble of finding Business to invest in that they hope will loos money.
We can offer to just put value into solution and combine it with so much junk as to render a large loss.
Sounds like a plan to me.

 

[UncleBenBen]

I can see value in setting up a bad reaction. But not quite the way you are going about it aga.

I've done countless small scale reactions and processes while learning this stuff in the past year or so. Quite the many of the small tests I've done have involved trying to recreate the problems I've seen posted in the Help Needed section. Like too much oxidizer, or leaving base metal undissolved. Then practicing overcoming those problems.

But while I found doing this invaluable to my education in refining, I never did it quite like that. I guess because I spent enough time reading before hand. And wanted to keep the waste from said experiments to a minimum.

You can still recover the tiny amount of gold from that motherboard. But I would use it as an opportunity to go ahead and learn to treat your waste. Which, let's face it. It's a large part of refining in itself.


Although I really like the tax evasion idea Justin!!

 

[Geo]

You can't throw a pile of electronics in a pot and gold bars come out the other side.

Ummmmmmmm,,,, :shock: Are you sure about that?

Ken :mrgreen:

Well, about as sure as I am that the sun will come up tomorrow. It's possible that it wont but highly probable that it will. :-D

 

[aga]

Spent the whole day today working out/experimenting what to do next with the Mess i made.

Ended up back with neutralising the acids with sodium bicarbonate, as the basic copper carbonate that (mostly) results will drop out of solution, killing 3 of the 100 birds with 1 stone, but only as a first step, not as a magic bullet.

Further processing planned for tomorrow. Results and entire details posted when i got the data - i.e. after it works or fails.

Unfortunately i cannot try to neutralise the nitric in any of the pots with sulphamic acid as i have less than 50g of that. A quick calculation says i'd use it at least All of it on one pot, which seems too much of a waste.

On a brighter note, the more properly treated finger solution has been evaporated down to 50% by holding it at 85 C which seems to be the point at which water vapour can be seen leaving the pot, yet there are very few bubbles of gas breaking the surface. Even so, likely some gold was lost at the same time.

Much better colour now and tests more obviously positive with SC in 30 seconds.
Tempted to precipitate and try melting or reducing the volume further, but feel it best to see if it gets a companion from the other Mess.

I did try dipping/drying the test paper before the volume was reduced and saw no perceptible differences between that and a freshly dipped paper.

Pondered for a while about refluxing while evaporating water, and fail to understand how that could work.
Something like distillation with a vigreux column might work, as the B.P.s of water and chloroauric acid are so widely separated, but i did not dare try, seeing as this is an attempt to recover from a Botched Job, and i know so little about the practicalities of gold extraction/refining.

usual rule of thumb is 1 ml nitric for each gram of gold and excess HCl

Could i ask what the concentrations of your nitric and hydrochloric acids are please ?

Knowing the concentrations of your acids will allow the calculation of how much '1ml' contains, therefore how much of what i have is needed for whatever the starting weight turns out to be tomorrow.

The HNO₃ i have here says 56% on the container, the HCl label says 20%.

 

[Geo]

Do you have stannous chloride? Don't do anything else until you have some and have tested the solution with it. A positive test means there is gold in solution and a negative means you have misplaced the gold to somewhere else. Not using stannous chloride in refining is like trying to bake a cake with your eyes closed. Test the solution with stannous chloride and come back and tell us what the test results are and if you can, a picture of the test results. Any advice you may have gotten or think you have gotten is useless without this test. If you get a positive test for gold, you will get more help on how to get the gold back.

 

[aga]

Do you have stannous chloride?

Umm, as per my statement in the vinegar/salt thread, Yes, i do.

"Made some Stannous Chloride test solution, as per lazersteve's post here :-"
viewtopic.php?f=41&t=5271#p45030

Without a Test, and knowing what the Test means, the rest is pretty much pointless.

As you clearly know that already, could you please give an idea as to What is the lowest concentration of gold that formulation of lazersteve's responds to, and/or how it degrades with time ?

I did not come here as a total noob to chemistry, so ppm, w% or molar fraction would all be equally useful.

Edit: Forgot the photo of the stannous test:

This is the way-over acidified fingers AR solution after evaporating down by 50%.
The one on the right was dipped and allowed to dry before testing. The one on the left is 'fresh'.

The papers are held in plastic clothes pegs and supported on a clean teflon stirring rod to make sure that the paper below has no effect on the test.

 

[Topher_osAUrus]

Well, when all else fails. Stock pot it.

Shouldn't ever be your "go to" method...because there is always a better way (mainly just removing all the base metals first before putting gold in solution) But, really, sometimes gold is in far too dirty of a solution, and precipitating wouldn't really do you any good. Whether it just wont drop the gold, or it would drag down too much junk. Cementing on copper is ALWAYS an option.
But now, with the acid neutralized...literally neutralized with baking soda.. You would have to reacidify it before more copper would be your saving grace.

 

[aga]

Well, when all else fails. Stock pot it.

Not an option : there is no stock pot, no easy way out.

there is always a better way (mainly just removing all the base metals first before putting gold in solution)

I agree completely with no hesitation at all, having spent/wasted at least 1 day already.

But, really, sometimes gold is in far too dirty of a solution

Now that is fascinating. Please explain what you mean.

 

[Topher_osAUrus]

Well, when all else fails. Stock pot it.

Not an option : there is no stock pot, no easy way out.

there is always a better way (mainly just removing all the base metals first before putting gold in solution)

I agree completely with no hesitation at all, having spent/wasted at least 1 day already.

But, really, sometimes gold is in far too dirty of a solution

Now that is fascinating. Please explain what you mean.

You MUST have a stock pot.. Its easy... Its the first step in waste treatment. Just get a 5 gallon bucket, have copious amounts of copper in it.. Now get another 5 gallon bucket, in this one have lots of scrap iron in it... Every solution that has the potential to dissolve gold (even HCl washes of powdered gold, if they arent reused for the next dissolution) go in the stock pot. It's how you catch all the minute amounts of gold that dont ppt, or little bits of pgm's that are in solution but aren't worth immediately chasing after. After the waste has been cementing on copper a few days (less if you have a bubbler running) then decant the solution to the iron bucket. Its best to keep up with the waste as quickly as you can so it doesnt build up and become overwhelming.

If you have alot of base metals in solution with gold, the precipitant can mechanically drag down the other metals besides gold in solution. Copper being one of them. SMB is "selective" in that it (usually) only drops gold.. But, it can precipitate copper as copper I chloride.. It can also ppt Pd.. And I'm sure if there were a myriad of other elements in solution with gold, some others would be dragged down too. Its really best to hold off on putting gold into solution, until its the ONLY element going into solution. Sometimes this isn't possible, but if it is at all avoidable, its in your best interest to do such.

But, if you have a really dirty solution that has gold in it, some here really advocate just cementing the PMs on copper to get a good clean shot at them.

I know I didn't explain that too elegantly, but, I hope I got the main jist of it across.

 

[aga]

I know I didn't explain that too elegantly, but, I hope I got the main jist of it across.

You did and very well.

Thank you for the detailed reply.