# I got robbed, but i got pictures!



## Palladium (Oct 3, 2011)

Got a question and a few observations. I found a jug of gold that I had left over from my experiments with way to much air and ap. I have about a half gallon of gold that I assume is trapped with tin. I took about 500 ml and dissolved in hcl Clorox. I filtered and precipitated with smb, no problem! I wound up with about 17 grams of gold, still no problem considering I didn’t know what to expect. The source materials were pins, fingers, circuit board traces and there should have been some pd in there to if I remember right. It had been sitting in the shed for about a year and a half and I had just forgotten about it. This stuff was so fine it looked black just like the tin so the only way to really see it was with a 600 X microscope. It was like oil like in water or silt it was so fine if you know what I mean. I sat around and though back and said humm I remember higher numbers coming from the other samples. I started with about a 5 gallon bucket of the material and won’t go into where the other 4 gallons went. So I never got to process any large quantity of the material. Now my dilemma. I dumped the solids from the filter into my Pyroceram dish and started drying the solids for residual recovery later. Let me stop and say if you ain’t using Pyroceram you ain’t using jack. This stuff has saved my ass and helped me more that I can say. You wouldn’t believe the abuse it has taken. Thanks Chris for the great tip. Pyroceram and Borosilicate glass, you can’t go wrong baby!!! They are cheaper if you buy more. I think I got 4 for like $150. http://www.shopworldkitchen.com/corningware/stovetop-just-white-casserole-jw-5c-b

As the water evaporated off and the hcl residuals started vaporizing i noticed the layer of water above the residue developed a oil slick or film of gold crystals. That was cool !!!! I have seen it do that when smb is added to a beaker without stirring. As it dried more it started to ooze what looked like amber tree sap from the now drying and crusty surface. Probably about the size of a pin head. That was pretty cool to. I also noticed gold crystals starting to form on the surface of these miniature mushrooms and the crust was turning the prettiest purple I have ever seen. I love purple. I just don’t like seeing it like that. That wasn’t cool. Lol After it dried I broke some open and it was purple all the way through to the purple stain on the bottom. Now what would be the best way to get this gold out of this tin? I thought incineration, but wouldn’t the gold vaporize off in this condition?


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## Anonymous (Oct 3, 2011)

(Scratches head) Geeees Palladium,what the heck?!? You have me stumped.My first instinctive answer was wet seperation.But then I thought you could try a very low temp heat.I have to admit...you have me a little stumped here.Maybe a melt.Someone speak up if they disagree,but I am suggesting to melt it with a tiny bit of powdered borax on the top,and a little flourspar mixed in.The flourspar should thin it enough to allow for a good agglomeration in the bottom,and the borax on top should assist in stopping any gold from going up.I am just shooting from the hip,so if someone sees something wrong with this,or has a better idea....speak up.I can ship you a couple of extra crucibles to sacrifice,if you need me to.


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## eeTHr (Oct 3, 2011)

Palladium said:


> The source materials were pins, fingers, circuit board traces and there should have been some pd in there to if I remember right.




It sounds like you are assuming that all the grey stuff is tin. Which sounds reasonable, because with HCl, when all the chlorine was gone, it would make stannous chloride, resulting in all that purple colloidal gold, plus some regular metalic gold from the SMB.

My question is, where would all that tin have come from? By "circuit board traces," do you mean entire circuit boards, with solder on them?

Can you redissolve and cement just the PMs with copper?

:?:



P.S. I had to reread to figure out that the 17 grams of gold was from the solution that you poured _*through*_ the filter, and this is the stuff that was left in that filter (residue). So the gold shown here is some that _*didn't*_ get dissolved in that solution. Do I understand that part right now?


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## Geo (Oct 3, 2011)

that would be a good candidate for that microwave furnace by the way it looks. naw. but really, what i would try is a quick boil in tap water then fresh hcl and some heat. let the liquid saturate and filter hot collecting all solids. dry the filter and contents and repeat. include the used filter. tin(II) chloride is water soluble and you should be able to wash most of it out that way. another way would be to add an excess of hcl and heat, add CL slowly till the gold dissolves and then evaporate as much moisture out as you can on low heat. after you have reduced the volume by at least half remove from the heat and let the solution cool. this will create salt that you can filter out. precipitate your gold without adding water with dry smb. you may get a few more crystals after the drop but a quick wash with hcl and the water will remove that.


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## Palladium (Oct 3, 2011)

That's the strange mystery about the tin. All the material that was recovered was from pin's, fingers, whole boards with gold traces, whatever, that was leached with hcl to remove the tin. After that ap. Then i run the recovered material through ap again the other day when all this started. After that i did a good hot hcl wash. All that was in this material by that time was gold and this black grey dust that won’t go away. I know it shouldn't be tin, but what else would react with the hcl residuals and the gold to form purple of Cassius?

When i dissolved it in hcl clorox i know the foils dissolved. It had to have gotten trapped the there during the time i was letting it settle so i could decant, 2 hours. I then drawed the top layer off and filtered that leaving the black powder in the beaker which i then poured the black powder in a filter to wash clean of any gold chloride. The reason i did this is because this stuff is a real pain in the butt to filter. So i precipitated my gold which wasn't a problem.

I waited 2 days for all the black powder to drain completely. But their probably wasn't 50 ml of liquid left trapped in the black besides the water i added to flush it. Of course here i was a couple of days later and was going to dry the residuals out for treatment later and you can see the results. I’m up for suggestions on what this gold robbing material is. If it’s not working as a cementation process then is it a catalyst reaction? I know that gold shouldn’t be in there but it is. I remember when I was adding the Clorox and generating chlorine gas that it seemed to take a long time for something that fine to go into solution. I thought then that the black powder was robbing the solution of free chlorine or tying it up in some way. Ain’t making good sense.


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## seawolf (Oct 3, 2011)

What about an incineration of the black powder then a trip through a 50/50 nitric at or just below a boil. If this dissolves the black partials test for PGMs and silver.
Mark


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## Palladium (Oct 3, 2011)

I just thought of something and i might be totally wrong, don't know. IF some of the residue was… i think i'm saying this right, palladium black, then couldn’t it be acting like a catalyst? I do know I have some pd floating around somewhere and it wasn’t in the gold drop. Could it be what trapped my gold and screwed with the cl reaction while I was trying to dissolve the foils? I didn't heat anything because i like to keep the cl in solution as long as possible. Only heat was from the reaction. Just shooting from the hip here. I don't have enough experience with the chemistry involved.


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## Geo (Oct 3, 2011)

unless you have a boat load of foils most of the dissolution happens in the first couple of seconds. now thats foils, gold powder on the other hand takes a little longer. no need to stretch it out any farther than you need to. i heat my solution a little because bleach is cheap and it dissolves powder faster.


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## Anonymous (Oct 3, 2011)

You could always put HCl in it and see if it absorbs any tin......if it does then you know you would be on the right path to eliminate it.


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## eeTHr (Oct 3, 2011)

I would recommend testing only very small amounts of the powders, with various acids.

HCl should dissolve out the tin, but it would leave the purple gold, possibly in suspension, making it difficult to decant.

Doesn't tin make a "gell" in nitric? That could be an indicator, right?


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## Geo (Oct 3, 2011)

eeTHr said:


> I would recommend testing only very small amounts of the powders, with various acids.
> 
> HCl should dissolve out the tin, but it would leave the purple gold, possibly in suspension, making it difficult to decant.
> 
> Doesn't tin make a "gell" in nitric? That could be an indicator, right?


metastannic acid. horrid stuff. avoid if at all possible. of coarse for testing purposes anything is possible. if you dissolve all in the filter with hcl/cl you can get the gold. it will be messy and you will have to be patient. heat the solution and dissolve, as it cools tin crystals will form, filter and precipitate, more crystals will form with the gold but not as much. dissolve again in hot solution and evaporate then let cool, more crystals will form, filter and repeat till no more crystals form then when you precipitate you have nothing but gold. messy but it will work.


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## artart47 (Oct 3, 2011)

Hi!
I'm a beginer but i had an idea! I remember hearing someplace here in the forum about the purple plauge in electronics industry AuAl alloy. I did a little experimenting to see if i could use aluminum as a test for the presents of gold in a solution. I put drops of my ap solution that i know has disolved gold in it,(it's the bucket that i've been doing cell board in and i belive the thin Au plating disolved) also drops from the lye solution for solder mask removal that took some gold from the boards and put the drops on Al foils to see if i could get a purple color.
You said that you had run board pieces.... could you have gotten some aluminum that's holding onto your gold and could explain the purple?
I'd be interested in what you think of my idea using Al as ...like a stanis test.
Hope It halps! good luck!


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## eeTHr (Oct 3, 2011)

Geo said:


> heat the solution and dissolve, as it cools tin crystals will form,...





Would diluting that solution prevent the formation of crystals when cool?

If so, then cementing the PMs with copper would work.


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## Geo (Oct 3, 2011)

even diluted the crystals will form, it just takes longer. copper will cement the gold but it will cement everything else with it. if he has already invested this much time and effort i feel he should just go for the gold and worry about what ever is left afterwards. but thats just my opinion.


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## Harold_V (Oct 4, 2011)

Geo said:


> copper will cement the gold but it will cement everything else with it.


Only those of value, although not silver. 

Were this mess mine, I'd be inclined to incinerate, then do a prolonged boil in HCl, after crushing and screening. I would then process the remains with AR, to recover values. 

Silver, as chloride, is likely to remain, assuming there was any in the beginning. Assuming there was, I'd be inclined to send the wastes to the furnace after extracting the values with AR. 

Harold


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## butcher (Oct 8, 2011)

I agree with Harold (of coarse he is right).

But before incinerating I would wash with caustic soda (sodium hydroxide) this would take the chloride from materials and form sodium chlorides this salt (table salt) would rinse from powders, this would lower chloride content and possible losses in the incineration process of gold or silver chloride salts, it can also help to oxidize some base metals in solution, sometimes I also use a peroxide rinse as well.

if you suspect tin is involved the dryer the product the better, as this gooyish tin material seems to hold liquid and not settle easily, and you can forget filtering.


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## Palladium (Oct 8, 2011)

Yeah Harold is right. In my small scale test it didn't seem to make that much of a difference, but when scaled up it should have been my first step. Just goes to show you can't reinvent the wheel. I knew better! :|

I’m taking note of everyone’s suggestions. I just haven’t had time to get back to the puzzle at hand. There is something weird about the whole deal and I’m trying to figure out what it is. It’s not so much that I have lost any gold as much as it is the fact I want to know what is going on and why. I have the materials in solution form, dry form, and the gold that was left over. I will be doing test on all of them to narrow it down. It’s the not knowing that bugs me.


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## butcher (Oct 9, 2011)

The purple color indicates tin and gold (cassius of purple) similar to the stannous test reaction, (and if it is), then the tin (and other base metals)may be cementing the gold, back to elemental metals.


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## Palladium (Apr 15, 2012)

Well i finally got around to figuring this out this weekend. Not refining has been killing me. I took all the powder and incinerated it this weekend and run it through hcl and then ar. The result was 5.6 grams. That was like a $250 robbery.


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## Palladium (Apr 18, 2012)

Well the mystery continues. After getting another 5 grams from this material I laid it to the side. Then I thought I was done but the plot thickens. I look on the filter paper that I removed from filtering the solution and saw tiny specks of gold. This was like microscopic size stuff. The process I was using to remove the copper used a lot of air and would blow the gold partices into fine dust that was almost to small to see. I thought hummmm……. Got my 600X microscope out and went to looking again and sure enough it was gold. A good bit at that! So I incinerated and run it again and so far I have a total of 26 grams I have pulled from this material and I’m still finding gold after that. Talk about a robbery!!!! Dam if this ain’t turned into an enigma of sorts. The material with the gold came from whole boards I was experimenting with a year of so ago. I ran them through hcl first to remove any solder, steel, or anything other that copper. This was after I of course removed any plastics or anything else I could before the treatment. After that all the materials that came off the boards where ran through ap to remove the copper and break down the monolithic capacitors and such. This material was then dissolved using hcl/chlorox. This is the 3rd go around and each time I have to incinerate once the solution quits leaching gold before it will start to leach again. The powders are always fine as dust at the beginning but once I have run them through ar the materials start to form little clumps about ½ in around and ball up into what looks like well worn river rock that is smooth and worn on the surface and has a silver gray texture. I know there is palladium in there some where and some silver also. I’m wondering if that could be it. Don’t know im not experienced with palladium yet. I’ve tried leaching the palladium and silver with nitric and nothing seems to be going into solution from my test. The black tin is gone now and I’m wondering what this is that’s left and why it won’t let go of my gold.The gold is in flake form and that’s what is puzzling me.


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## nickvc (Apr 19, 2012)

If this was my problem, I have even bigger one, and I was sure I'd removed all the tin I'd convert all the metals with zinc dust wash and filter and then dissolve the silver and palladium out with nitric, rinse well and then dissolve the gold with AR.
The reasoning been that your sure you have both silver and palladium in there so let's remove them and hopefully have just gold left as a value to worry about, stannous is going to be needed as you know, others might not, just in case any PGMs are left after the nitric to be dissolved in the AR solution.


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