# In the beginning, working with green fiber cpu pins!



## awgv001 (Apr 7, 2013)

*Hello refiners of new and old!* :mrgreen: 

Before I begin, I assure you, I have read Hoke and have a digital copy, and through trial and error, will be working forward to produce results both good and messy :shock: .

My inventory for this project:
150g of clean gold-plated pins from green fiber CPUs
3000ml beaker w/ Glass stirring rod
950ml HCl (32%)
950ml H2O
damp cloth or filter to minimize fumes (this project is done in a shed with air vents at the top, and with the double doors wide open.)

I started off my process using the "goldnscrap" method of removing Kovar materials from fiber CPU pins in a HCl bath, 150g of pins (with no MCC's mixed in)
H2O and HCl were mixed to a 50/50 dilute (total 1900ml solution for 150g of pins without peroxide)
It's been in the bath for a couple days now, and it was initially heated with a hotplate, however, I have left it undisturbed for the last couple days to perform my regular job.
I don't have peroxide handy at the moment, but it's on my to-do list. My overall goal with this small batch is to recover the gold, remove BMs from the leftover HCl, and to do it in a neat, timely, safe, and organized manner.

Now, from the details on the website. The majority of all BMs should be dissolved leaving nothing but gold foils in the mixture.
Could I add peroxide to the mixture after I've put the H2O, HCl, and pins together and get identical results, or is that only during the portion in which the pins are originally having the Kovar removed?
I'll add more to this upon my next evolution in this phase, along with some pictures of the different phases. 8)

If I posted this in the wrong place, I offer my sincerest apology, still learning my way around.


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## butcher (Apr 8, 2013)

You can put in the 3% hydrogen peroxide in most any time, or bubble in air, the color of the solution is a clue, if it is very dark green/brown it needs oxygen, if it is light green you have enough oxygen, if dark brown and you see white powders (copper I Chloride) you need a little more HCl.

Have you read the document on Laser Steve's web site that explains how the copper II chloride leach works?


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## auction_junkie89 (Apr 10, 2013)

Enjoy! 
These are photographs of gold-plated CPU pins 3 hours from beginning to dissolved in 32% HCl.
(1 part HCl 950ml, 1 part h20 950ml)


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## butcher (Apr 11, 2013)

Laser Steve is a member and moderator here on the forum (look for his name and he has links to his web site).

Your solution is very dilute with water, You do not need all of that water, you can heat it and the water will evaporate concentrating back the acid, as the acid concentrates it will dissolve more metal.

you should also go to the general chat section and take the guided tour of the forum.


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## AUH-R (Apr 13, 2013)

Hi, I have been doing a similar project and you may find this thread very useful: http://goldrefiningforum.com/phpBB3/viewtopic.php?f=39&t=9693

Best wishes,


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## auction_junkie89 (Apr 17, 2013)

For my next step, I will filter out everything in the solution, including the material at the bottom and the gold foils at the top, which I assume are the undissolved PM's with the BM's removed?
Then, in drying the filtered goods, weight them out, and then add AR based on the weight of the undissolved material.
If I'm missing anything, I thank you all sincerely, and appreciate all your help. I hope that this post will help to cover some of the finer details with the processing of specific gathered materials.
I'll also add a final tally, and picture of my first baby button with the completion of this exercise!


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## auction_junkie89 (Apr 17, 2013)

Also, does anyone know what the rectangular silver-ish pieces I noted may have been amongst the CPU pins in this batch? 
They seem to have been floating around in the batch well before the solution had time to change color and react.


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## nickvc (Apr 18, 2013)

While not directly related to this topic can I suggest you do not put your beakers directly on a hot plate, there are several alternatives but a corningware casserole dish is one good one as it will also act as a catch dish should any mishaps occur saving your hot plate, solutions and values.


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## auction_junkie89 (Apr 19, 2013)

That's a genuine idea right there, thank you very much!


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## auction_junkie89 (Apr 24, 2013)

*Alright*, the wait for the next step of photos and questions are here. 
Been working a new job, so I had to set the experiment aside.

*The steps I performed to make these photos:*

*~~~* So the HCl and pins solution seems to have come to a stopping point.
I brought the solution to a near boil again to evaporate some of the water, and dropped the volume of the solution to about 1650-1700ml with little golden flakes and foils floating around inside. 
A beautiful sight I'll add, for it being my first time seeing this in person.
I then decanted to a filter, and made sure to spray any leftover matter off the walls and base of the beaker, again, to the filter, and allowed the filter to drain and collect the foils and leftovers.

*~~~*This is the part that makes me a bit nervous to move forward, so I approach this with much patience and caution.~~~
*~~*Ask, before you make more of a mess, right? :wink: 

I'm pretty sure that the next step would be:

To allow the filter to drain, and dry the leftover pins and foils caught in the filter and process this dry matter in AR.
The issue is that there's a lot of black/powdery material, and what looks to be like dirty not-completely-dissolved pins within this mixture, however I'm not sure if what's there is comprised of PCMs that won't dissolve in HCl alone.
I want to move forward, but I don't know if these pieces introduce too much base metal into the AR in the state they are in.

Enjoy the pictures, and if you can help out, I'd greatly appreciate it. 
I have a lot of material to process, and I have the time to work on them at a comfortable speed.
I'd like to be confident on how these stages look when they are performed, as I'm sure many other people are too. 
Also, it would be great for any in between steps that aren't typically covered or mentioned, if needed, for the occasional/inevitable accidents.


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## auction_junkie89 (Apr 29, 2013)

The pins and their foils were not finished dissolving, even after a couple sessions of boiling, I noticed that many still had much further to go, and it wasn't for the lack of acid, it's because i hadn't read up about the Copper II process, so I'm going to add the pins and foils back to the solution, gently spraying them off with a spray water bottle, and then I'm going to go look for something that will bubble my solution.


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## auction_junkie89 (Apr 29, 2013)

I have an air compressor nearby, which can be regulated down to small bubbles, would that work? Any suggestions?


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## Geo (Apr 30, 2013)

you can dissolve the Kovar base metal in processor pins using hot hcl but it is a slow process if you are processing them in any quantity over a few grams at a time. after the solution turns dark blue/black, it is an indication that it has dissolved all the iron it can hold. in my experience, 1 gallon of hcl will only dissolve about 2 pounds of Kovar.


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## auction_junkie89 (Apr 30, 2013)

Geo said:


> you can dissolve the Kovar base metal in processor pins using hot hcl but it is a slow process if you are processing them in any quantity over a few grams at a time. after the solution turns dark blue/black, it is an indication that it has dissolved all the iron it can hold. in my experience, 1 gallon of hcl will only dissolve about 2 pounds of Kovar.



So, I used a fairly small 950ml bottle of HCl figuring that the max I could dissolve was close to 150 grams of pins, but, as mentioned earlier by butcher, I didn't have to make my solution 50/50 of H20 and HCl.

My plan at this point is to put the pins back into the solution, and boil it down to about 1200ml that way the HCl is back to a stronger concentration.


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## stardust18 (May 26, 2013)

auction_junkie89 said:


> Geo said:
> 
> 
> 
> ...



Greetings. I think it will not work because the water boils at 100 degrees Celsius, and hydrochloric acid at 76. So that the acid will evaporate first. If I'm wrong - please correct.


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## Geo (May 26, 2013)

hydrochloric acid boils at 84 C. 84° Celsius = 183.2° Fahrenheit. water boils at 100 C but it will evaporate at a much cooler temperature. you can evaporate a solution until it reaches 32% hcl and then you will start losing acid. you can evaporate liquids without heat. ever notice that the ice cubes get smaller in your self defrosting refrigerator? the water is pulled out by the much colder condenser which is defrosted and drains out the back into a pan. the same effect happens in a desiccator or de-humidifier.


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## auction_junkie89 (Jun 14, 2013)

Well, I'd overheard that I could also use 50/50 of sulphuric acid, and that it works better than using the HCL, however I don't know the pro's and con's of using this method, or the ratios of the solutions vs amount of material being processed.


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## auction_junkie89 (Oct 26, 2013)

So, still working with this same batch, not going to give up trying! I heated the solution to just before boiling, and evaporated about half of the solution, and the reaction seems to be working a lot better at this point.

The solution sits at 1200ml, and has been a couple weeks since I checked on it :-/ been too busy lately to keep up with it all.

Now, with the leftover solids in this solution, what should I do?


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## patnor1011 (Oct 26, 2013)

The only leftover solids from 150g of pins should be few (1-2) pinches of black powder and few pinches of foils.
Use more HCl, give it a time to do the job.


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## kkmonte (Oct 26, 2013)

Your compressor idea might work but I'd avoid it. All i can imagine is having a hose from my compressor in the beaker and someone opening up the valve all the way and it blowing the solution everywhere. I'd suggest spending the $8 and getting one of these:

http://www.amazon.com/Tetra-77851-Whisper-Pump-10-Gallon/dp/B0009YJ4N6/ref=sr_1_1?ie=UTF8&qid=1382831885&sr=8-1&keywords=aquarium+aerator

or something similar at the aquarium store. Also buy the tubing that you need and also spend a few bucks and buy a check-valve, if the tube was to come off the air pump, the check valve will prevent it from creating a suction and sucking all your acid out of your container all over the place.


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## auction_junkie89 (Nov 12, 2013)

butcher said:


> Laser Steve is a member and moderator here on the forum (look for his name and he has links to his web site).
> 
> Your solution is very dilute with water, You do not need all of that water, you can heat it and the water will evaporate concentrating back the acid, as the acid concentrates it will dissolve more metal.
> 
> you should also go to the general chat section and take the guided tour of the forum.



Thank you, Butcher,

I evaporated the solution down to 1200ml so far, and now i have many more foils blissfully floating around


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## auction_junkie89 (Nov 12, 2013)

To my best understanding, using the a sulfuric cell method would be the most (cost) effective (and less time consuming) method of stripping the gold foils from the pins.
I currently have about 1800G of gold pins from fiber CPU's, so perhaps using gallons of HCl isn't the way to go when processing Kovar pins, but it has been a fun learning experience this far, and I will continue to process this batch until I retrieve my little golden pea. ^_^


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## butcher (Nov 12, 2013)

When you get that gold be sure to show it off in the gallery section.


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## auction_junkie89 (Nov 12, 2013)

butcher said:


> When you get that gold be sure to show it off in the gallery section.



Absolutely!


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## auction_junkie89 (Nov 12, 2013)

Hey Butcher, by the way

Once all of the pins have dissolved, then I can treat the black sand and foils in AR and drop with SMB for the final product, correct?


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## butcher (Nov 12, 2013)

auction_junkie89,
I would wash the powders and foil, but if the foils do not float around easily and still have some base metal inside sitting a little while in a small jar of HCl with a little peroxide can help to finish base metal removal in the pins (sometimes it is hard for the acid to get to the base metal deep into a tube where bubbles are trying to come out and block the acids entry, after base metals removed, you can wash the powders and foils in a boil of HCl and then with hot water washes, before dissolving them, let foils and powders settle well before decanting the wash solutions, usually you will need to lower heat for them to settle, and give them time, but I like to decant the wash while it is still as warm as I can.

If you are not familiar with aqua regia, you will be better off dissolving them in HCl with small additions of sodium hypochlorite NaClO (household bleach), taking care not to add to much NaClO, as the chlorine it generates to dissolve the gold is much easier to remove with heat, if you do not over use it to begin with, This is normally easier for someone who is not familiar with aqua regia, and the common problems with it like boil-overs, and de-NOxing the solution. This material you are working with thin foils and powders will dissolve into the HCl/NaClO just fine, so you do not need to use aqua regia, which is more aggressive and will dissolve thicker pieces of gold.

After you have the gold dissolved, and have given the solution a good heat treatment.
No need to concentrate the solution to remove the free chlorine in solution. 
No need to dilute the solution.
If you let this sit overnight the solution will clear, and normally any insoluble lead, silver salts or other materials will be on the bottom of the jar, carefully decant or transfer the solution, suction bulb and pipette, works better than pouring solution, so you do not disturb settled powders, filter your gold solution, into a very clean vessel to precipitate gold in.

Then you can precipitate the gold with the reagent of choice, if you use SMB dissolved in water, mix up a solution with just a little more SMB that you have in gold weight, use this solution freshly after mixing it up, it would be best not to add all of the solution at once, add a good portion of it and give the gold solution a good stir, when you get to the point that you have added almost have added enough SMB the solution will begin to change colors from yellow to brown gold forming in solution, using your stannous chloride to determine when you have used enough SMB and no longer have dissolved gold in solution, let this gold sit overnight, recheck with stannous again, if all of the gold stays precipitated decant the gold barren solution from the gold powders.

Now we need to wash the gold powders, you can do this in the same beaker (if the vessel can handle being heated), I normally transfer the gold powder to a 50ml beaker and do my gold washing in it,
http://goldrefiningforum.com/phpBB3/viewtopic.php?f=49&t=325&hilit=getting+gold+pure+shining


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