# Properly botched job



## aga (Jan 8, 2017)

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.


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## jeneje (Jan 8, 2017)

aga said:


> 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.


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## aga (Jan 8, 2017)

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.


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## g_axelsson (Jan 8, 2017)

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...


aga said:


> 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.



aga said:


> 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


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## aga (Jan 8, 2017)

g_axelsson said:


> 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.


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## FrugalRefiner (Jan 8, 2017)

aga said:


> g_axelsson said:
> 
> 
> > For the gold in AR, I suggest denoxing by evaporation to get the volume down
> ...


Evaporate, do not boil.

Dave


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## g_axelsson (Jan 8, 2017)

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


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## aga (Jan 8, 2017)

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 NOx 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.


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## Geo (Jan 8, 2017)

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.


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## jeneje (Jan 8, 2017)

Geo said:


> 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:


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## justinhcase (Jan 8, 2017)

Geo said:


> 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.


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## UncleBenBen (Jan 8, 2017)

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!!


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## Geo (Jan 9, 2017)

jeneje said:


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


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


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## aga (Jan 9, 2017)

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.



g_axelsson said:


> 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%.


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## Geo (Jan 9, 2017)

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.


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## aga (Jan 9, 2017)

Geo said:


> 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.


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## Topher_osAUrus (Jan 9, 2017)

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.


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## aga (Jan 9, 2017)

Topher_osAUrus said:


> Well, when all else fails. Stock pot it.


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



Topher_osAUrus said:


> 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.



Topher_osAUrus said:


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


Now that is fascinating. Please explain what you mean.


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## Topher_osAUrus (Jan 9, 2017)

aga said:


> Topher_osAUrus said:
> 
> 
> > Well, when all else fails. Stock pot it.
> ...



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.


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## aga (Jan 9, 2017)

Topher_osAUrus said:


> 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.


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## Topher_osAUrus (Jan 9, 2017)

8) 

Copperas (ferrous sulphate) is actually a pretty good precipitant for dirty solutions. But, I would still say if its a really dirty solution just cement with copper... That way you arent increasing the bulk of the waste solution (copperas requires dissolving in water, then adding hcl to it, er'go adding to waste) but if you feel you need to ppt instead of cement from dirty solutions its good to use copperas for the first precipitation, then smb for the second. As each has their own unique contaminant possibilities. Using each one for each of the purification steps helps cut down the contaminants and end up with pure gold. 

You want to go the extra mile and be a try hard, do the third precipitation with oxalic acid and get it really beautiful!


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## jeneje (Jan 9, 2017)

There are a few things one needs before starting to refine. Let's take a look at them.

1). Your standardized test solutions.
(Gold standard, Platinum standard and of course Palladium standard).
2). Then, you need your test solution, Stannous Chloride and DMG at a bare minimum.
3). Then, one must have the never fail go to - A Copper bus bar for all those i had gold days and can't find it. :lol: 
4). And then, as been mentioned, the almighty stockpot for your retirement :shock: . 
5). When you are still lost and are scratching your head, saying where is my gold? Break out the old Hoke's book and start at chapter-one.
I am sure I missed a few finer points but, hell it's late and time for bed. :wink: 

Good luck,
Ken


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## Geo (Jan 9, 2017)

I agree with Ken. Obtain some 18K scrap and dissolve a gram in 30mls of solution. This will be your test standard. You use it to test your stannous chloride against it to make sure your stannous chloride is still good. Stannous chloride is very sensitive to precious metals in solution. It can detect minute amounts of gold in solution. When you do it enough, you can even gauge the amount of gold in the solution according to the test results. To acquaint your self with it, use your test standard and dilute small one drop samples with fresh HCl to test. That way you can see how much of a stain is left by a very diluted samples. 

Your test looks like a negative. If you are sure that all metal dissolved, look at what's left of the material to make sure, there is still too much solution to get a good, positive test. You may have to evaporate what you have again by half. And again and again until the gold shows with stannous chloride. Also, dissolve some known gold metal to test your stannous chloride against.


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## aga (Jan 10, 2017)

Thanks for the tips Topher, jeneje and Geo.

A Stock pot sounds like a good plan. 

Currently i'm 'processing' just this one old PC, so there will be no further wastes to be handled in the immediate future (sounds like everyone's famous last words !).

For precipitation there is SMB and iron (II) sulphate on hand, but no oxalic acid. There is some pure vitamin C which i understand can be used in some situations, but do not know which. Ditto fructose.

I guess having a Standardised test solution is the best/only way to test the stannous chloride.

If/when any metal gets coaxed out of this Mess, making a chart of the appearance of the SC test with increasing dilutions of some AR-dissolved bought/authenticated gold will be a good exercise.

DMG does not seem to be easily available as crystals (ebay).

I think everyone will agree that Hoke's refining book should be swapped from #5 to #1 :wink:


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## g_axelsson (Jan 10, 2017)

Since you like experimenting, doing the acquaintance tests in Hoke could be a good exercise. There also is a lot of similar experiments in her second book, Testing precious metals.

My acids are technical grade concentrated, HCl at 30-35% and nitric at 70% but I usually dilute the acids to save on them and cut down fumes. It means that reactions can take a longer time, but I'm seldom in a hurry.

Göran


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## anachronism (Jan 10, 2017)

As Goran said. FYI "not being in a hurry" really really works in this game.....


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## aga (Jan 10, 2017)

Thanks for the information guys - calculating the amount of nitric needed right now.

It's already been 2 full days of solid work to get to a position where all of the original metals (hopefully) are in 1 pot. Turned out that the pot is too small so had to go for 2 pots  

It's almost at the stage where the base metals can be removed and the gold extraction begins.

Should be able to get there sometime tomorrow morning.

If so, i'll proceed all the way to the melt - if there is anything to melt !

Full details tomorrow with any luck, including whether it ends a success or a failure, also photos of the whole sorry tale.

Oh ! Even if any gold happens, there's the refining to do, twice, if there's enough gold for that ...


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## upcyclist (Jan 10, 2017)

Speaking of patience, nitric, and stockpots/cementing: Be sure to use lots of agitation (an aquarium bubbler will work) and time when you're cementing. Cementing will be harder with metastannic acid and silver chloride mucking everything up.

Oh yeah, since you applied AR to everything, your silver is likely in the muck, too, as silver chloride. _Edit to add_: and silver chloride is essentially insoluble in nitric and hydrochloric acids.

--Eric


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## aga (Jan 16, 2017)

After many days of fruitless effort, i could not recover the gold.

Right now, all the liquids are in a 'stock pot' with some copper pipe and a bubbler.



Topher_osAUrus said:


> Well, when all else fails. Stock pot it.


Change that to "Before pointless efforts fail, Stock pot it."

The notes are long, tedious and depressing. A full write-up would be more so.

In brief, here's what i tried, and how i failed :-

1. Yellow liquid only :-
Evaporate down to 15%. Metastanic goop. Add water, heat/stir to re-dissolve. Drop gold with SMB. 
Fizzed too much due to xs acid. Added sulphamic. Pot fizzed over. Lost 50% of volume.

2. Blue/green liquids :-
Neutralise acids with sodium bicarbonate. Filter, saving filtrate. Put all papers/solids in a stainless steel pot and pyrolyse, then incinerate.
Pot contents ended up a solid block. Break up, wash out, dry, weigh, add calculated 650g nitric to remove more copper. More fizzing, overspill (again).
Days of just filtering/drying/evaporating 3 litres of liquid.
Resulting solids dried, weighed, calculated volume AR added, HNO3 in portions, left overnight/all next day, stirring/warming.
Filtrate very dark green.
Accept failure, rig up a stock pot and dump the lot in there.


The Lesson is basically to do what more experienced people tell you do.
Saves a lot of wasted time and effort.


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## jeneje (Jan 16, 2017)

It is always better to deal with Metastannic acid (goop) as you call it early on in the process. Once you have created it, the best way I have found is to incinerate the Metastannic acid using red heat and then dissolve in HCl to remove it, leaving your gold foils or ? ever. 

Hope this helps you next time you run into it.

Ken


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## g_axelsson (Jan 16, 2017)

Told you so! :mrgreen: 

Göran


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## aga (Jan 16, 2017)

g_axelsson said:


> Told you so! :mrgreen:


Yep, and you were Right because you Knew !

Having wasted so much time & effort, i'll never ever go down a random path to try to recover/refine any PMs.

It hasn't be a lot of fun, but it has been a Lesson well and truly learned :
No messing about, just follow a tried and trusted procedure if a good result is required.

Next up is to recover any gold from the stock pot as-per Hoke's instructions in chapter XIII.

I was thinking a week should be enough time to leave it bubbling.

If anyone recommends longer, then it will be left for a longer time.


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## aga (Jan 16, 2017)

Some photos of the whole sorry business :-


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## Topher_osAUrus (Jan 16, 2017)

aga said:


> A
> Evaporate down to 15%. Metastanic goop. Add water, heat/stir to re-dissolve. Drop gold with SMB.
> Fizzed too much due to xs acid. Added sulphamic. Pot fizzed over. Lost 50% of volume.
> 
> ...



Don't feel too bad, I think everyone here has tried to cut a corner or two at one point in time. I was cutting corners left and right when I started "refining"...but the school of youtube wasn't the best place to find out the best practices ....eventually I found the GRF and was dumbfounded by how much I didn't know...

edit to add: disregard that neutralize to 7 question. I realize now, that you were speaking of the material that you pyrolized and incinerated not the solution you threw in the stockpot.


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## aga (Jan 17, 2017)

Topher_osAUrus said:


> Was the solution still hot when you added the smb?


Umm, yes  

Lots of fizzing when adding SMB, plus some NOx fumes. Adding less than a pea-sized amount of sulphamic acid fizzed it out of the pot. Shame, as that pot was the only one concentrated enough to give a result with SC.



Topher_osAUrus said:


> Did you neutralize to 7? or..? the stock pot needs to be acidic..Hoke says to just add a bit of HCl


I will check the pH today, also re-read the 'Stock Pot' chapter and make notes before touching anything !


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## upcyclist (Jan 23, 2017)

jeneje said:


> It is always better to deal with Metastannic acid (goop) as you call it early on in the process. Once you have created it, the best way I have found is to incinerate the Metastannic acid using red heat and then dissolve in HCl to remove it, leaving your gold foils or ? ever.
> 
> Hope this helps you next time you run into it.


I caught early on that I don't need to run HCl-only solutions through my stockpot, but I got some metastannic acid in my stockpot even earlier than that. I also realized a little too late that I should run a separate stockpot for silver nitrate.--now I have both metastannic acid (some) and silver chloride (lots) in my stockpot.

Should I try to convert the AgCl before I incinerate for metastannic? There's still a fair amount of copper solids in there, but we're talking about a liter of solids at the bottom of the stockpot. It's mostly silver, and I don't want to find out that incineration is a good way to lose *all* the silver. Thoughts?


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## Topher_osAUrus (Jan 23, 2017)

upcyclist said:


> I caught early on that I don't need to run HCl-only solutions through my stockpot, but I got some metastannic acid in my stockpot even earlier than that. I also realized a little too late that I should run a separate stockpot for silver nitrate.--now I have both metastannic acid (some) and silver chloride (lots) in my stockpot.
> 
> Should I try to convert the AgCl before I incinerate for metastannic? There's still a fair amount of copper solids in there, but we're talking about a liter of solids at the bottom of the stockpot. It's mostly silver, and I don't want to find out that incineration is a good way to lose *all* the silver. Thoughts?


I stockpot my HCl solutions that i rinse powder gold with, or if they arent "dirty" after that, I use it for the recovery AR dissolution of gold, then fresh HCl for the refining stages.
It is suggested to keep AgCl wet since it becomes difficult to get a full conversion when its dry -especially if its chunky.
If its just a wee bit of tin sludge, you may just want to go ahead and convert the AgCl. Accepting the small amount of impurity the tin will add, removing it at a later refining stage.
...i think that would be better than drying out and crusting up your AgCl
Hoke says that metastannic is soluble in sulfuric, and of course AgCl is not... But, my experiments with that have shown the tin sludge isnt *truly* soluble in it, it just becomes colloidal almost, and will settle out if given ample time.

So maybe it's just best to convert it with dilute sulfuric and iron and go from there.. 

Or maybe convert with NaOH then rinse and dissolve in nitric. Leaving the tin sludge behind. Of course your copper bits would go in solution with it, but the tin would be able to be filtered off.(slowly!)


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## upcyclist (Jan 23, 2017)

Thanks--I needed a sanity check on that. I didn't mention it earlier, but yeah, I'd pull out the copper first as well as re-refine the silver (depending on how clean it looks, save it for a cell or run through nitric again). I'll incinerate whatever's left after the conversion (I too prefer sulfuric & iron), since there should also be gold in there. 

I didn't mean gold-rinsing HCl, btw--I was referring to HCl soaks & polluted CuCl2/__Clx used for removing base metals.


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## Topher_osAUrus (Jan 23, 2017)

upcyclist said:


> Thanks--I needed a sanity check on that. I didn't mention it earlier, but yeah, I'd pull out the copper first as well as re-refine the silver (depending on how clean it looks, save it for a cell or run through nitric again). I'll incinerate whatever's left after the conversion (I too prefer sulfuric & iron), since there should also be gold in there.
> 
> I didn't mean gold-rinsing HCl, btw--I was referring to HCl soaks & polluted CuCl2/__Clx used for removing base metals.



Im with you now, and agree. Sulfuric/iron is quick and easy... But, i like hcl/zinc for agcl crust on goldfilled material.. I had very good luck recovering silver and gold with that method. (I had it caught in filter papers, so i didn't want the sulfuric to make a mess of them)


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