# Unknown precipitate



## maynman1751 (Nov 17, 2011)

I incinerated some computer flat packs and SMD's and crushed them to powder. Then processed them in AP solution for several days with aeration and heat, filtered, rinsed several times and put the material in HCL/CL for 2days, filtered and diluted by 3X. Everything went fine to that point although the AuCl was still slightly greenish. I then added 2 tblsp SMB dissolved in hot water to the solution in several portions with a minute in between additions. When finished adding SMB I stirred the solution and it immediately turned the color of red wine!!??? This was very unexpected. I let the solution settle overnight. At first there was a whitish chessy looking fluff in the bottom with a reddish somewhat crusty material on the surface of the liquid and caked to the sides of the pot. I stirred the solution and the pictures show what I ended up with. In all my readings in the forums and all the pictures, I've not seen anything like this. Any ideas.....HELP!!!!


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## lazersteve (Nov 17, 2011)

Have you tested with stannous?


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## maynman1751 (Nov 17, 2011)

Yes Steve and it turns the Q-tip dark brown like gold should....right?


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## Geo (Nov 17, 2011)

brown can be a false positive.a positive will range from light purple to black with brown being a couple of different things.copper shows brown and even too much SMB will give a brown test.


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## goldsilverpro (Nov 17, 2011)

I agree. Purple or black is what I always see for gold. The black is just very dark purple.


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## maynman1751 (Nov 17, 2011)

Geo, I've done about 6 or 7 different 'batches' and they always test brown!!!??? What am I doing wrong? Not getting all the copper out?


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## Claudie (Nov 17, 2011)

Did you let the Chlorine evaporate before you added the SMB? 
Did you remove the magnetic material before you put the material in the solution?

EDIT: Never mind that first question, I misread your post. :|


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## maynman1751 (Nov 17, 2011)

I let the solution set overnight before dropping and picked out any metal that was visible... I'm not experienced enough to know to check for magnetics. I didn't realize they were used in this application.


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## maynman1751 (Nov 17, 2011)

I just went out to check on my SNAFU and did another stannous test. The test showed deep orange!!!! Platinum-NO WAY!!!! Also, the white material has again separated from the red.


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## Geo (Nov 17, 2011)

test with DMG to assure PT. you dont want get too excited for another false positive. and besides orange is a positive for palladium not PT.


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## Geo (Nov 17, 2011)

remove all the solids you have so far and redissolve them in hcl/cl. this time the solution should be more yellow,be sure to test with stannous.anything that doesnt dissolve is something to further test.if its flatpacks there could be AgCl that might make up some of the white pasty substance.if anything doesnt dissolve in hcl/cl use some ammonium hydroxide as this will dissolve small amounts of AgCl.


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## maynman1751 (Nov 17, 2011)

I hate like heck to correct you but, Orange is Pt and not Pd, according to what I just checked.


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## maynman1751 (Nov 17, 2011)

I thought that the white might be AgCl but I wasn't sure since I have not run across that yet. Also, there is a considerable amount of the white 'cheese', 1/4 to 3/8" thick. Will the white dissolve in Hcl/Cl? or do you know yet until I try it?


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## philddreamer (Nov 17, 2011)

If I may share Steve's pic.
Purple/Black color is Gold in solution, the darker the spot the more Gold.

Yellow/Brown that turns to Blue-Green after 30 seconds indicates Palladium in solution, the darker the spot the more Palladium. 

Orange/Brown color is Platinum in solution, the darker the spot the more Platinum. 

http://goldrefiningforum.com/phpBB3/viewtopic.php?t=562#p4766

Phil


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## butcher (Nov 17, 2011)

maynman1751,
Just some things for you to think about.

You have dissolved a wide variety of metals, and may even have other things in this from the ash or plastic materials, so the colors and how the soup reacts may not be the same as if you are dissolving just copper and gold pins.

You tried to rid most of the base metals with acid peroxide solution before trying to dissolve the gold. A wise step now let me ask a couple of questions just to make you think.

Did all of these base metals dissolve in the acid peroxide process, if they did not my values may be plated back onto the metals that did not dissolve, then my values may not be in this solution, or maybe only a portion of them?

Could I have metals like iron making this red color, or who knows what other metal involved here would give funny colors to my solution.

Could I have maybe some organic, plastic, or ash or other, giving me some reaction I do not recognize? 

I could Have a wide Varity of metals here base metals, and valuable metals, maybe even PGM metals, how do I find out if I have values here, testing of course, but could one metal in my solution effect the color of the stannous test for another metal?

maynman1751, I am not sure I will be much help but I will try.

The white powders can be many things like table salt NaCl from the bleach and acid, it could be lead chloride from the solder, or silver chloride if silver was there, could maybe be ash or some other nonmetal,
If you can separate the white powder try some of these, salt NaCl will dissolve in water easily, lead chloride is insoluble in cold water, but lead chloride will dissolve in boiling hot water. Silver chloride will not dissolve in hot or cold water, but silver chloride will make a complex with ammonia and dissolve (Caution do not let this solution dry it can be very dangerous), (adding HCl to the silver dissolved in ammonia solution will form white silver chloride (milk or powder) silver powder, and also make the solution safe again).

If the stannous chloride test looks black you may try and dilute it to see if it changes purple.

You could have other metals that react with stannous chloride test for gold like some platinum group giving you colors that are hard to read.

Make sure chlorine or other oxidizer like nitric if used is gone from the solution you are testing.

Try a spot plate, white tea cup or white spoon, add some of your solution few drops, add a crystal of ferrous sulfate look for a brown ring around the iron salt crystal (gold test) if brown ring there is gold, now let the gold precipitate in your spot plate or cup, take eye dropper and move solution to another cup, white spoon, or spot on spot plate, now that we removed the gold we will test this with stannous chloride to see if we get reaction for platinum or palladium, 

I will not go into details but you can use this same method by separating say platinum from the palladium using a few crystals of ammonium chloride to precipitate the platinum (or sodium chlorate to remove palladium),

DMG would be a better test for Pd.

If all else fails cement values on copper and redo it.

Take a break from it and reading Hoke's book you may find your answer.

I hope this gives you some Idea’s


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## Claudie (Nov 17, 2011)

When you say "flatpacks" are you referring to the Gold corner packages that are often found on motherboards and have a green fiber bottom, or the packages that have legs on all four sides?


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## Geo (Nov 17, 2011)

i may be color blind. :shock: my wife and i both see different color on that Q-tip she said it was red,i thought it was deep yellow.i might need someone to double check my test. oh well,i can see purple well enough. :lol:


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## Harold_V (Nov 18, 2011)

Geo said:


> test with DMG to assure PT. you dont want get too excited for another false positive. and besides orange is a positive for palladium not PT.


No good. The reaction to a test for platinum with stannous chloride is, indeed, orange. It can be as dark as coffee, depending on the concentration. Palladium, tested with stannous, can give a myriad of reactions, but blue/green are common. I've had it respond as if it's gold (dark blackish brown), and differentiated by the lack of a purple stain in the spot plate, or a positive test with DMG. DMG does not test platinum---it is a test for palladium.

Upon edit----I see that others responded to this as well. You folks are coming along admirably. 

Harold


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## maynman1751 (Nov 18, 2011)

Claudie said:


> When you say "flatpacks" are you referring to the Gold corner packages that are often found on motherboards and have a green fiber bottom, or the packages that have legs on all four sides?



It is a mixture of both but mostly the the four legged variety.


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## maynman1751 (Nov 18, 2011)

[


> quote="butcher"]maynman1751,
> Just some things for you to think about.
> 
> You have dissolved a wide variety of metals, and may even have other things in this from the ash or plastic materials, so the colors and how the soup reacts may not be the same as if you are dissolving just copper and gold pins.
> ...




These and other questions have been spinning around in my mind! I am very new to this and have been basicly trying small batches to try and get the formulas and procedures done correctly. Most things have worked out quite nicely and when they didn't further searches and reading within the forums have explained my results. But man, this one really blind-sided me! That is why I have posted this result. I have some, but not all, of the testing chems that I need to check for or to react with all of the situations that I may encounter.

I will try the suggestions given to me and see what I am able to discern with what I have available. Because of the weather conditions setting in, my refining days are numbered (I'm doing my work in an un-heated area outside of the house) safety first!!!!! I will report my findings as they come. I may have to just wrap things up until Spring. This will give me more time to study and READ,READ,READ!!! :wink: 

Thank You (Butcher) and all for your wonderful responses to my dilema.


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## maynman1751 (Nov 18, 2011)

I know other members have processed this same kind of material the same way that I have. What elements do these components *usually *consist of? What were they able to reap from *their* processing?


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## samuel-a (Nov 18, 2011)

maynman1751 

This kind of material is somewhat complex to process, especially if you are not sure what to expect.
This raise even bigger difficulties for the inexperienced refiner.

If you read spec sheets of said chips you will learn alot about their possible metalic composition.

Proper incineration is key for effective recovery. If you don't have a fancy industrial incinerator (which most of us don't) you will find that you need to grind and incinrate again. 
The organics in those chip package (plastics, epoxy resines etc'...) are packed in layers or one thick layer, your initial incinration may only combust the outer shell of the chip's package and leaving loose carbon inside.
The 1st incineration will eliminate some carbon and all the volatiles, the 2nd grind/incineration will handle the rest of the carbon.
In my mind, it will also be wise to set a fly ash scrubbing, though, in RI 7683 it is reported that no sugnificant amounts of metals were found, let alone PM's.

From my experience, Iron presence is negligible, where the majority of the base metals are copper or copper alloys, Lead and Tin. Pins maybe coated with Ni or Au over Ni which gives them magnetic capabilities and therefore making life easy in terms of seperation by strong magnet.
Those pins are better processed separately from the ground ashes. IMHO.

In terms of PM's presence:
Ag and Au, that much you know.
It is not suprising to find presence of PGM's as well, such as Pd and Pt and even Ru (IV)


Here are the colors of SnCl tests:
















False due to Sulfurous acid (exsess SMB):






Take note, that Gold stain is the only one that will not fade after several hours.
testing very dirty (lot's of dissolved base metals) solutions will produce sometimes strange color reactions.


Pd(HDMG)2 drop looks like that:



(Note: it is floating due to the stirrer)

Hope this helps you in some way...
Good luck.


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## butcher (Nov 18, 2011)

samuel-a, 
very well done.


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## maynman1751 (Nov 18, 2011)

Thanks Sam, nice explanation. I incinerated mine ( maybe improperly) with an oxy/acet torch. Even after completely turning cherry red, I continued to heat them hopefully burning out all of the contaminates. I then did indeed crush them and re-incinerate. I remember reading about carbon being trapped or not being eliminated (I think). The little bits of info that I have found about processing these devices never explained their complexities or perhaps I would have waited until I had more experience. Sam, do you have any input on where to go from here? Thanks, John.


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## philddreamer (Nov 18, 2011)

I was going to make a comment on "incineration", but first, I did a search to find the correct definition before writing & I found the different reasons & ends for WHY we, (who recover & refine PM's), apply heat:

"BURNING - burning, combustion - the act of burning something."

"INCINERATE - (ɪnˈsɪnəˌreɪt) 
— vb to burn up COMPLETELY; reduce to ashes. 
[C16: from Medieval Latin incinerāre, from Latin in- ² + cinis ashes] 
inciner'ation 

"PYROLYS is a thermochemical decomposition of organic material at elevated temperatures WITHOUT THE PARTICIPATION OF OXIGEN. It involves the simultaneous change of chemical composition and physical phase, and is irreversible. The word is coined from the Greek-derived elements pyr "fire" and lysis "separating".

"CALCINATION - (kăl'sənā'shən), in metallurgy, process of heating solid material to drive off volatile chemically combined components, e.g., carbon dioxide. It is sometimes a step in the extraction of metals from ores. Calcination is distinguished from drying, in which mechanically held water is driven off by heating, and from roasting, in which a material is heated in the presence of air to oxidize impurities. Originally calcination meant the method of obtaining lime (calcium oxide) from limestone by heating it to drive off carbon dioxide."

"ROAST - In metallurgy, To heat (example: ores) in a furnace in order to dehydrate, purify, or oxidize before smelting, (or digesting, dissolving).

So, I learned something new from this search, & will try to use the proper terminology for the different reasons WHY I apply heat, before or after any given process of material, & the end result for which I used any of the above methods.
(I hope I"m making sense.) 

Phil


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## samuel-a (Nov 18, 2011)

maynman1751 said:


> Thanks Sam, nice explanation. I incinerated mine ( maybe improperly) with an oxy/acet torch. Even after completely turning cherry red, I continued to heat them hopefully burning out all of the contaminates. I then did indeed crush them and re-incinerate. I remember reading about carbon being trapped or not being eliminated (I think). The little bits of info that I have found about processing these devices never explained their complexities or perhaps I would have waited until I had more experience. Sam, do you have any input on where to go from here? Thanks, John.




I think you should first seperate solids from liquids. Dry the solids and incinirate them.
Then, run them in dilute hot nitric, wash and run them in AR.

With the liquids, try and cement out every thing with Cu slab for few days, notice color changes of solution and SnCl tests until negative.
Remember, you need to provide large surface area of copper when cementing. I'm using a radiator fins made of copper.


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## maynman1751 (Nov 18, 2011)

This is the result of the stannous test that I just took.


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## patnor1011 (Nov 22, 2011)

First of all is to define what did you burned. crushed, dissolved - I have no idea what is "four legged variety" and what you meant by "smd"
It will be extremely useful if you put here few pictures of material - you can use google image search to show us material you included and you cant photograph because it is crushed...

You did not dissolved much of basic metals by letting them sit in AP for 2 days only. This process need much more time it depend on volume of material involved. 
If I will be in your situation I would incinerate everything and use diluted Nitric.


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