# mini test



## bmgold (Oct 24, 2008)

As a mini test of the acid peroxide and acid clorox process I am attempting a tiny test batch to keep from risking my very limited supply of gold plated electronic scrap and to avoid producing a lot of waste. 

To start this test a few bits of gold plated foils from a smashed open processor chip were added to a test tube and some HCl was added to cover them. Then a little hydrogen peroxide was added. In about 5 minutes or so the color changed from yellow to green and then almost brown. This liquid was poured into another test tube and then more acid and peroxide was added to the materials being tested. The visible copper went into the two solutions and then this was added to the first liquids and the materials were washed a couple times with water which was also added to the copper containing solutions. Next some more acid was added to the materials to cover them and a little clorox was added which bubbled and turned the solution a yellow color. This was poured into a fresh test tube and the materials were washed with water and this wash was added to the yellow liquid. Now a small amount of SMB and water was mixed up and added to the solution which turned clear instantly. After several hours a tiny amount of light brown coating is stuck to the glass. I expect that this is the gold but am not sure since I didn't test the solution before adding the SMB but since the visible gold vanished it has to be either still in solution or it IS this coating. The PH of this solution is still at 1. The amount of gold in the few foils must be very little so I hope that if more material is extracted and before it is precipitated the liquid is added to this test tube the coating should dissolve and add to the new precipitant but this has not been tested. I hope to eventually get enough to melt or smelt into a piece big enough to touch. So far my experiments have resulted in small beads of silver colored metal that takes good light and possibly a magnifier to even see. I am working with small amounts of ore (crushed rocks) and some fingers and chips so I didn't expect any quantity of gold in the tiny samples being tested but hope to learn the processes from my experiments.

Has anyone else tried processing tiny amounts of materials? When I scale my extracting up to larger quantities I hope to recover the copper and other metals to add a bit more value to the effort as well as to keep it out of the wastes to be gotten rid of.


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## lazersteve (Oct 25, 2008)

You are not learning proper recovery or refining procedures by doing all the reactions in the same solution.

You likely used way too much AP for such a small amount of material and all of your material was put in solution in the first recovery operation (both base metals and precious metals). When you scale up this will change as the ratio of base metal to reactants will increase and the reaction will behave differently (the majority of the gold will not dissolve).

You certainly have a trace of gold powder in the residue you mentioned, but you have not removed the base metals from the solution. This step is vital in the refining of larger batches. You can not process everything (base metals and precious metals) together and expect to get fine gold.

I think you have proven to yourself that the reactions actually work. That is good. Now I would recommend that you preform the same test on a 50 gram sample of e-scrap material to see the difference. 

This time try to keep the gold in foil/flake form (don't dissolve the gold with the AP) and filter out the base metal AP solution. Any larger insoluble material will have to be removed by hand (ceramics, plastics, etc) and rinsed. Then the dirty rinsed foils ('mash') will need to be treated with HCl-Cl, filtered, and precipitated.

After you get the residue of brown powder from this reaction, incinerate to red heat (don't melt) then do the HCl-Cl (or AR) reaction a second time to get the gold purity up.

I also recommend testing with stannous often so that you can learn to identify pregnant and barren solutions.

Good initial ground work, now it's time to take the next step.

Steve


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## bmgold (Oct 25, 2008)

Maybe I wasn't clear enough in my explaining but my gold flake was attached to a bit of inner circuit board that stayed in the original test tube and is still in that test tube with a little water to try to keep it from sticking in there. It is mostly ?fiberglass?

The total amount of AP used for the first two soakings along with the wash water is, I would guess, a tablespoon and a half maybe two tablespoons and most of that is from the wash water because water is cheap and I wanted as much of the copper containing solution (green liquid) as possible removed from the material as possible. The gold was still visible on the original material and was not floating around in the solution but stayed in its original test tube. The green liquid was saved separate from everything else. 

Will the stannous test show up gold in a mostly copper containing (green) solution? I still have that liquid saved in a jar for future cleaning to remove the copper when the volume increases as well as recovering any gold that it might contain. 

Then, with the visible gold still attached to the thin sheet of material that I would guess is fiberglass, it was covered with, I would guess, about 1/8 teaspoon of HCl and say 10 drops of clorox bleach. This is the point where I noticed the visible gold go into solution and along with the wash water from this step only, it went into another clean test tube and the non-metal part still remained in the first test tube. This small amount of liquid (1/2 inch high in a test tube) and a solution of a pinch of SMB and almost the same volume of water as the liquid in the acid/clorox was mixed up and mixed together with the yellow liquid where I thought the gold was. It got clear but this may have been because of the doubling of the volume to an inch high in the test tube. 

Anyway, I still have all of the materials and liquids in separate containers so where ever the tiny bit of gold went I still have it. It is probably good that I didn't test this with much gold but more gold would be easier to notice precipitating and dissolving. 

Thanks for the help but I want to make sure we understand each other before I change things. Actually, for larger amounts I would have to change things like filtering instead of just carefully pouring out the liquids since the thin flakes would probably not settle out as easy as in the tiny test I did so far.


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## bmgold (Oct 25, 2008)

I thought of one more question. While rereading the forum handbook vol. 1, I see that it says if gold is present in the AP to drop with SMB. Will this also drop the copper combined with any gold or would it only drop the gold?


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## butcher (Oct 25, 2008)

SMB will drop gold first if in proper ratio, but will also drop copper,if you add more than just the exact amount needed to drop the gold, there are several other precipitant"s that can be used to drop the gold, some will not drop copper as easily or at all. most of the time we reuse or AP rejuvinating it, till we are done with it, and then drop any gold it might contain. you can test a solution of gold with copper with SnCl2 but it isnt as easy,with base metals to tell results, as it is in solution with lower base metal content,
you said you were doing very small amounts as test run, to me this would be difficult, as it is hard to drop gold without some still being left in the acid (unless very pure solution) (or without dropping some of the base metals), larger amounts also will cling together better and drop to bottom and not cling to sides of your glass as bad.


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## bmgold (Oct 25, 2008)

I guess I need to quit playing around and just do it as an all or nothing shot. I just don't have that much gold and wanted to be sure I could get it back once I start. Other than some chemicals I don't have much other than time invested since the stuff I have to extract is/was just scrap. 

I'll just have to set up a ventilation fume hood and just ah... Go for the gold. 

Thanks everyone. Great forum. I'll post my results once I get the scrap separated from the computers and circuit boards ready to refine. Sure wish gold coins were easier to come by but then I guess it wouldn't be worth doing if gold was cheap.


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## butcher (Oct 25, 2008)

just dont toss anything you can always get yer gold back, if I didnt have much scrap gold would probably concentrate on setting my lab up, studying processes, making tools and gathering supplys finding more scrap gold,reading forum, shoot then I would have a pile of scrap, and be prepared to handle it (almost) :lol:


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## lazersteve (Oct 25, 2008)

Bmgold,

With your new explanation it sounds more like what I'd expect. 

The only thing I notice is that you mentioned that the gold foils where still clinging to the fiberglass. The foils should be floating freely in the liquid before you pour of the AP. Sometimes the foils need a little coaxing to float free, so I use my spray bottle to knock them loose. Other than that, everything sounds right on.

Steve


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## bmgold (Oct 25, 2008)

That sounds like good advice. I will concentrate on setting up a safe lab and keep reading and collecting and preparing my scrap and the start extracting and refining the gold. 

Thanks for the advice. I guess I proved it will work.


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## bmgold (Nov 2, 2008)

I just couldn't wait so I tried a slightly larger test with the fingers from 1 circuit board (probably a dozen small fingers but didn't count them) and with a little SMB dumped in without predissolving it, I am now getting a definite precipitate that is black but has some white powder with it. Might be undissolved SMB. Probably should add some water to dilute the solution but might just let it sit overnight and see what happens. 

No luck with homemade stannous chloride test yet so I must not be making it right or it may need diluted before use. I have to do some more reading on it. I used an inch of lead free solder and HCl with heat but it didn't dissolve completely. Then a drop of the solution to be tested was put on a filter paper and a drop of the stannous was added. The paper only got wet with no darkening. 

I am ordering all of lazersteve's dvds so I can see the right way to do this before I use up all my scrap. I'm saving everything I've done so far to reclaim when I figure this thing out or for my retirement.


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## bmgold (Nov 2, 2008)

I think I found my problem with my stannous test. On page 95 (or 104 in pdf version) of Hoke's book it says "Sometimes the colors fail to appear. This may mean that the testing solution has lost its strength, or, more likely, too much strong acid is present. "

I did have a very strong HCl/clorox solution that the gold was dissolved in. I don't know if the answer to this problem is to use a more dilute acid solution to do the dissolving in or to neutralize the gold containing solution a little with baking soda or weak sodium hydroxide solution or if just adding a drop or two of water to the test drop might work. I already dropped the metals out so can't test it again. Maybe someone else can answer that question. 

Where did I hear READ HOKE'S BOOK before?

Thanks Harold_V for your standard newbie question answer. It is right.


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## Lou (Nov 3, 2008)

Try adding a drop or two of distilled water to the test drop.


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## bmgold (Jan 1, 2009)

I've had a mixture of crushed cpu chip and plated fingers in a container of HCl and H2O2 for a month or more and decided to filter the solution to get the gold out. As you can see from the picture, the result was a filter with a lot of dirt (crushed chip) and some gold foils. I didn't rinse the filtered result or do anything except filter some of the liquid out to collect the gold. My plan is to try to rinse this mess as well as some other filters into another container where I can continue the process. I might have to burn the filters if the gold will not rinse off but I expect the gold to just wash off and into another container. I also have a paper towel that I tried to use as a filter on another attempt. This was probably not such a good idea since the gold is stuck in/on the towel. This one will have to be burnt to release the gold. 

Would rinsing this dirty mess of gold and chip dust with water to get rid of the copper containing acid and then using some HCl/Bleach to dissolve the gold work to separate the gold from the dust?

Did I do this completely wrong or am I on the right track? If I did this wrong how should I have dealt with the powder from crushing the cpu and other gold containing flatpacks? Maybe decant the copper containing solution and rinse a couple times then dissolve the gold without using the filter until separating the garbage from the gold.

The materials I used were soaking in the AP solution in a shed with no heat and lots of cold days. The solution is very dark so must contain a lot of copper. I will eventually try bubbling air through it or maybe adding a little more peroxide to try to rejuvenate it so I can use it some more. If this don't work I guess I'll try to get the copper out with a piece of steel.

I may not get back to finishing this test until I have more material ripped out of the computers and other e-scrap so I end up with more than a speck of gold for my efforts. I'm really looking forward to getting that first bead of "pure" gold and want it to be big enough to touch. I've seen the tiny, almost microscopic beads from doing torch assay tests and they are nice but bigger would be better. I'm getting closer thanks to the information and help I've gotten from this forum. Thanks all.


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## SilverFox (Jan 1, 2009)

Having experience processing small amounts like this for my test batches i can tell you it would be a total waste of your time to go any further until you have something worth using the SMB on.

That small amount would barely be visible on the bottom of your beaker. Let alone something you could physically collect later.

Id store the foils up until you have a few grams at least.


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## bmgold (Jan 1, 2009)

> That small amount would barely be visible on the bottom of your beaker. Let alone something you could physically collect later.



That's what I figured. I have probably 3 times as much as is shown in the picture on separate filters just waiting for more to process before going any further. I tested some going as far as the smb and then dumped the whole thing into a jar to wait for a later time to process it. It was enough to barely see but I knew it wouldn't have made a bead big enough to see without magnification.

What should I do with the crushed residue from the chips? Should it all be processed with the HCl/Bleach? The picture just shows the stuff that ended up in the filter trying to pour off the AP with the floating gold foils. There is still a lot more material as well as some more gold with the more solid stuff (chip parts and stripped circuit board from the fingers). Still not enough to process the whole way to melting into a bead but maybe enough to go on to the next step (HCl/Bleach) to eliminate the majority of waste material. Will the HCl/Bleach with the dissolved gold in it store for later processing or should you precipitate soon after you dissolve it? I guess the volume of material isn't to much to save all of it and since some or most of the copper has already been removed, it should be easier to process later and maybe another pass through an AP leach along with more fresh material may not hurt anything other than taking more volume of acid to cover all the material. It might even help remove any copper that was missed the first time through.


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## butcher (Jan 2, 2009)

Warm HCl/bleach will leach your gold from crushed chips.
storing in solution would probably work as long as storage vessel was not glass with lid, which could build pressure and explode(chlorine will try to gass out).if thats your choice maybe dilute it and store in old plastic acid or peroxide bottle.
Would probably be better just to store them as broken chips till you get more to process.
As others have stated such small batches and losses in processing may be ok for expierimenting with, but not good for collecting gold.


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## bmgold (Jan 2, 2009)

Looks like I need to quit playing around and just get to work. Maybe it's time to finish my gold stripping cell and maybe "cheat" a little and process a bit of 10K scrap to add to the volume. 

I can easily get a bunch of flatpack chips to process but I've held off on even messing with them since there is little to no visible gold on them. I guess that since I have them here a large enough quantity of microscopic gold might just add up to a visible amount. 

I also have (still in the connectors) a hundred or more phone connectors that are gold plated to rip out and process as well as some other gold plated wires and connectors to tear out. 

Like I said, I really want to get that first bead of refined gold. 

Thanks again for all the encouragement and help. There's no way I could do it without the knowledge gained from this forum.


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## qst42know (Jan 2, 2009)

If you have some 10k scrap to process I would process it by itself. Karat scrap is such a clean simple straight forward process compared to e-scrap the experience is not to be missed. It really sheds some light on the complexity and difficulties of processing poor sources such as e-scrap.


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## bmgold (Jan 2, 2009)

I do have a little bit of 10K and 14K scrap that I got to try to refine. If my calculations are right and if I got 100% recovery I should have enough for around 1/4 troy ounce of refined gold. That should be enough to see and touch. 

The nitric acid is what is stopping me from processing this material. I have everything I need to make the poorman's nitric but the fumes still concern me and it is still to cold to work outside so I'll have to keep learning and dreaming for now. I might dig up some of my junk e-scrap and get some more materials together ready to extract and refine while I wait for some warmer weather.


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