# Dust on the bottom after adding SMB



## beneq1 (Nov 17, 2013)

Hello
It is my second try and again something is going wrong and I don't know what is happening that why i need your help. 

I was fallowing this guide and I have done every think step by step: http://www.goldnscrap.com/index.php/scrap-cpu-a-chips/91-gold-recovery-process-from-ceramic-cpus-part-1

As fist step I added 160 ml HCI and some water to 8 ceramic CPU's that slowly Nitric Acid (1-3 ml at the time). I stopped after about 2 hours, because there was no reaction and i have not seen any metal. After filtering I add 2-3 balls of urea to see if I need to neutralize Nitric Acid. Nothing happened with urea so i added a teaspoon of SMB and solution start to bubble. After 1 min I walked away to give it time and come back later. After about 30 min I came back and on the bottom of beaker settled white/yellowish dust. Please help me with it.


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## butcher (Nov 17, 2013)

beneq1,
Even if you have a good step by step process to follow, it is unlikely you will be able to complete the process without any problem, and thus unless you have a good understanding of the basics you do not know what to do next.

You have to understand the basics of recovery and refining.
this will take time to learn, begin with Hokes book and study of the forum.

I have not read the process you followed so I will not comment on it, although I am sure it is a working process, written by a person who understands the basics of recovery and refining, he can write the process, and it can be a good process, but unless a person who was working with the process understood the basics of recovery and refining was working with this process and had an understanding he would likely not have luck when things were a bit different in the chemistry throughout the process, a beginner may not have success with the process without this basic understanding 

I do not see where you de-NOxed the solution, although you added nitric in increments you could still have added more than needed, I see no mention of using your stannous chloride.


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## beneq1 (Nov 17, 2013)

Thanks for the advice.

For sure I will read that book and get stannous chloride, than try to finish process.


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## beneq1 (Dec 7, 2013)

Finally, I managed to get some free time and SnCl2 to do it. I bought SnCl2 in store and prepared as CM. Hoke said (page 93). I tested it 3 times, photos attached. It isn't black or purple (after first 2 sec it was black but then changed) so I'm not sure if it good. If it is good can you tell me what I should do if gold dosen't drop and I have dust on the bottom of the beaker after adding SMB.


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## butcher (Dec 7, 2013)

To me it looks like some purple of Cassius in the upper photo, the paper itself seems to have a slight violet color.

Have you tried to de-NOx the solution?


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## moose7802 (Dec 7, 2013)

What type of cpus did you run?

Tyler


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## beneq1 (Dec 7, 2013)

butcher said:


> To me it looks like some purple of Cassius in the upper photo, the paper itself seems to have a slight violet color.
> 
> Have you tried to de-NOx the solution?



No



moose7802 said:


> What type of cpus did you run?
> 
> Tyler


Ceramic Intel Pentium


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## moose7802 (Dec 7, 2013)

Honestly if you only ran 8 cpus you might be lucky to get .3 grams. That type of cpu averages between .9-1.1 grams per #. In that first picture where you see the colloidal Au floating on top might be half of the Au you will get out of those 8 cpus. I also don't see where you diluted your AR with at least 2 times the amount with h20. So there is a good possibility that the whitish yellow color at the bottom is Ag. The silver chloride sometimes look yellow in the AR from ceramics until you siphon and rinse the AgCl. 

Tyler


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## beneq1 (Dec 8, 2013)

So now I should filter it and dilute it more, then add SMB?


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## butcher (Dec 8, 2013)

Personally I would still suspect free HNO3.
I do not think you have eliminated it as a possibility.

I would add a bit of sulfamic acid, dilute and let it sit overnight, decant and filter clear solution, before precipitating.

Also I would de-nox a small sample in a test tube and retest the solution with stannous chloride, to see if the purple appears any better.

Or use one of the other methods to de-NOx your solution, if using the evaporation method I would do it before dilution of the solution.

Heating the solution with a gold button...

Sulfamic can be found at Home depot they sell it in the flooring section as grout cleaner.


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## moose7802 (Dec 8, 2013)

Follow exactly as Butcher has explained. You would be defeating the purpose if you filter first then dilute. You want to dilute to push out the AgCl and add sulfamic at the same time to kill the free nitric and drop the lead that may be in your solution. Sulfamic is the best way in my eyes to rid your solution of free nitric and dropping lead because it's like killing 2 birds with one stone.

Tyler


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## Geo (Dec 9, 2013)

i believe that Richard and Tyler are doing good a good job at helping but i feel i should comment. 8 CPU's will yield enough gold to barely cover that beaker with dust. what im trying to say is, you may have done everything and got most the gold the first time. if you test solution without heating it and waiting for it to cool, it could still have SO2 in solution causing a false positive. at least heat the solution and wait for it to cool. if you can, test your solutions by adding a drop of solution into a white plastic spoon (test sample). add a drop of stannous chloride to the test sample. a good solid purple color change is a good sign. if it doesn't show purple instantly, set the spoon down in a safe place. over the next few hours, you may see a color change. the longer you wait, the better. observe the color and then, with a spray bottle, rinse the solution from the spoon. don't touch it, just rinse it. if the stain remains after rinsing, there's a significant amount, enough to reclaim. 

i know that's long winded, and i apologize. i figured it wouldn't have helped you out much to tell you to retest your solutions.


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## moose7802 (Dec 9, 2013)

I totally agree with Jeff.

Tyler


moose7802 said:


> Honestly if you only ran 8 cpus you might be lucky to get .3 grams. That type of cpu averages between .9-1.1 grams per #. In that first picture where you see the colloidal Au floating on top might be half of the Au you will get out of those 8 cpus. I also don't see where you diluted your AR with at least 2 times the amount with h20. So there is a good possibility that the whitish yellow color at the bottom is Ag. The silver chloride sometimes look yellow in the AR from ceramics until you siphon and rinse the AgCl.
> 
> Tyler


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## beneq1 (Dec 13, 2013)

Geo said:


> i believe that Richard and Tyler are doing good a good job at helping but i feel i should comment. 8 CPU's will yield enough gold to barely cover that beaker with dust. what im trying to say is, you may have done everything and got most the gold the first time. if you test solution without heating it and waiting for it to cool, it could still have SO2 in solution causing a false positive. at least heat the solution and wait for it to cool. if you can, test your solutions by adding a drop of solution into a white plastic spoon (test sample). add a drop of stannous chloride to the test sample. a good solid purple color change is a good sign. if it doesn't show purple instantly, set the spoon down in a safe place. over the next few hours, you may see a color change. the longer you wait, the better. observe the color and then, with a spray bottle, rinse the solution from the spoon. don't touch it, just rinse it. if the stain remains after rinsing, there's a significant amount, enough to reclaim.
> 
> i know that's long winded, and i apologize. i figured it wouldn't have helped you out much to tell you to retest your solutions.



That explained a lot. So, tell me if I am correct. Now I should heat it, than wait it for cool. Take a test sample and test it. Than de-NOx it by adding a pinch of sulfamic adic until is stop fizzing (than on the bottom should not be any dust?). Solution is diluted already, it was around 150ml now it is 300ml, should i dilute it more? Yes I know 8 CPU's isn't much but now I am just learning and if I mess up it isn't going to be a big loss.


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## jeneje (Dec 13, 2013)

It could be my computer, but, it looks as through the solution is a grey/purple. If it is, that a sign of colloidal gold or silver caught in suspension. 
Ken


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## beneq1 (Dec 13, 2013)

jeneje said:


> It could be my computer, but, it looks as through the solution is a grey/purple. If it is, that a sign of colloidal gold or silver caught in suspension.
> Ken



No, it is only sediment that is gray. Solution is very, very dark yellow.


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## jeneje (Dec 13, 2013)

beheq1, 
The grey sediment is colloidal gold. You will need to filter the solution, catch all the sediment in a filter, incinerate and re-process to get the gold. For the solution you filter off, follow the advice already given.

Hopes this helps you out.
Ken


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## beneq1 (Dec 13, 2013)

jeneje said:


> beheq1,
> The grey sediment is colloidal gold. You will need to filter the solution, catch all the sediment in a filter, incinerate and re-process to get the gold. For the solution you filter off, follow the advice already given.
> 
> Hopes this helps you out.
> Ken



Sorry but I'm not sure if I understood it right. I need to filter and collect sediment from filters and burn or just dry it (should I use oven)? Than put in in AR and than add SMB to drop gold. 
For solution that left from filtering I need to de-NOx it by adding a pinch of sulfamic adic until is stop fizzing. Yes?


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## jeneje (Dec 13, 2013)

beneq1 said:


> jeneje said:
> 
> 
> > beheq1,
> ...


*Do not use an oven* Filter, let dry, incinerate in stainless steel bowl, re-process. *DO the incinerating* outside or inside a fume hood. You should research incineration on the forum to learn how.
Ken


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## butcher (Dec 13, 2013)

Gold that was dissolved in solution, and has begun the precipitation process, where gold ions begin to gain electrons and form atoms of gold metal particles which combine in solution to form particles of clusters of these invisible gold atoms, as these small gold atoms move in solution these gold atoms crash into each other, or collide they combine and coagulate into each larger particles, which grow in size, clusters of atoms clash to form larger particles,as these particle's grow towards forming larger particles and then crystals of gold large enough to be visible in solution these larger particles of gold are then pulled to the bottom of the vessel by gravity.
These gold atoms being neutral (no static charge are free to randomly crash into each other and combine and grow to form a precipitate of gold metal crystals.

colloidal gold is these gold particles which have stopped growing in solution, their growth stunted in the process, the invisible gold atom particles are neutral (no charge) but surrounding Ions in solution can hitch a ride onto the outer shell of these growing clusters, the outer shell of the gold cluster particle can then become electrostatically charged, as these ions that attach themselves can be either negative or positively charged Ions, this gives an electrostatic charge to the growing gold clusters, now with all of these invisible gold clusters being charged of the same polarity (by the ions attached to their outer shell), these gold clusters of atoms stop growing is size, they repel each other as like charges repel, for them to grow and precipitate they must be able to come into contact with each other, this being impossible now, as they have become electrostatically charged they cannot do this they push each other away, this also keeps them in solution and in movement so they will never settle.

The gold is reduced (full atoms of gold particle clusters of atoms) so we cannot test for them with our stannous chloride.
We cannot reduce them with the cementing process of using another metal like copper (they already have all their electrons and need none from copper).
we cannot see the colloids the particles are so small they are invisible, but we may be able to see a color.

The Tyndall effect of light is where a light shine through a solution and when colloids are in the solution the small gold particles reflect the light on the side, the color of the reflected light has a direct proportion to the size of the gold colloidal particles in solution, this color may be red, blue or violet, one test for a colloid is to shine a light beam through solution and view from the side. this reflected light the Tyndall effect is proof of colloidal particles.

Gold colloids are so small they will pass through most filters even a ceramic filters, so we cannot filter them out of solution.


The stannous chloride test where we purposely reduce gold forming a colloidal gold solution with colloids of gold of a certain size, so that we can see this Tyndall effect of the purple colored solution, to indicate gold was previously in solution (but now metal floating in a solution of colloidal gold giving a purple reflection of light).

Dirt, oils, organics, tin, solutions loaded with base metal ions,and other factors can promote the formation of colloidal gold, and can cause a refiner lose a tremendous amount of his gold if he is not careful, and learns to recover and refine the gold properly.

These colloids of gold can sometimes be broken (hard to do but can sometimes be done).

High heat which can also concentrate solution (bringing particles closer together) and moving particle faster in solution, giving them more chance to come into contact together, the heat also can help to increase acidity, can help to break the colloid, and help these particles to lose their static charge and come together as larger particles to form crystals of gold that will precipitate.

Changing PH can also help to break a colloid, strong acid (Heat can also help here).

Adding an ionic salt (electrolytes) of opposite polarity of colloids is one way to break a colloid (but here you would have to know the polarity of the gold colloid and you would also be introducing more salts to contaminate your solution (not something I would recommend in recovery or refining), we could make the situation worse if we added the wrong ionic salt to solution.

Electrolysis of a solution, where we create an electric field and push the colloid to one electrode or the other, depending on polarity of the colloid, which is actually the polarity of those attached ions on the outer shell of those colloidal gold particles, so here we can force the gold to the anode or the cathode depending on the ionic charge of the colloidal gold which can be either positive or negative depending on conditions that formed the colloidal situation (and the particles may have a better chance of collision)...

Then we can also break the colloid by evaporation under heat, crystallizing the powders, incineration of, or roasting them, to burn off organics which could have caused the problem, or oxidize and wash tin which could have also be the source of trouble, and caused the problem, or dissolve and remove some of the the base metal contaminates, before we put the gold back into solution in a much cleaner situation to avoid this problem again...

We can see where incineration to remove organics, keeping tin and certain metals out of solution with gold in solution, and removing base metals before dissolving gold, and other techniques we have been taught become very important, and helpful to prevent from forming colloidal gold. Or how these precautions can keep us from tossing out our gold with those baby gold colloids in that dirty old bath water.


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## beneq1 (Dec 14, 2013)

wow, thank you very much for explanation of what's going on. I never would have thought that it is so complex.

I was heating it for about 3h and after it has cooled down, I did that what Geo told me and it went black instantly. 
During the heating process, in better the light I noticed that the solution not only dark yellow but (I dont know how to explain it) inside it is brawn. grey/purple was only suspension on the walls of the beaker and dust on the bottom.

Now I need to filter it, collect and dry dust from filter and de-NOx solution?


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## beneq1 (Feb 12, 2014)

Thanks you very much for help guys. I got 0,27g gold from it ;/. But next time it will be better I hope.


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