Gold inside chips (black, flatpacks - not CPU)

[patnor1011]

Depending on type of chip it can be a lot of copper and I would go for nitric leach first. That do have some other advantages, some chips contain Ag/Pd brazing, Ag will be dissolved in this leach along with copper.

 

[Phillip Barrett]

Does anyone know what temperature it takes to burn the chips to a good ash? I have an old pottery kiln and was thinking of running a couple of pounds in it but i dont know what temp. to set it for. Do you think about 1000 to 1200 degrees F. would cook them enough or is that too hot?

 

[GotTheBug]

You might run into a lack of oxygen to properly incinerate in the kiln. I'm using a small, home built foundry, lid off, with a steel container to contain the chips. There are holes drilled into the container to allow flame and air to pass over the chips, which sit on a steel screen inside the container. At approximately 1200 degrees, it takes 5 minutes to completely incinerate 300 or so grams of chips. Next time I do a run I'll take some pics.

 

[g_axelsson]

Temperature should be enough to get the chips red glowing and then enough time and air that the center turns into ash and loses the black coal. The more packed together the chip are the harder oxygen have to reach the center.

Göran

 

[Phillip Barrett]

Thanks a bunch guys for the fast answer !!! I just joined the forum less than a week ago and all i want to do is get on and read, read,read, I thought i knew a little about this but find out i know nothing !!! Just love it, so much to learn. I just ran across a bunch (lucient 1674ct48 chips). Is there any way of finding out from the number if they have any gold content without running a sample first? Again, Thanks for answers !!! Pillip

 

[solar_plasma]

Can you post a picture?

 

[Geo]

Thanks a bunch guys for the fast answer !!! I just joined the forum less than a week ago and all i want to do is get on and read, read,read, I thought i knew a little about this but find out i know nothing !!! Just love it, so much to learn. I just ran across a bunch (lucient 1674ct48 chips). Is there any way of finding out from the number if they have any gold content without running a sample first? Again, Thanks for answers !!! Pillip

Trying to chase down part numbers from mixed scrap is a huge waste of time. Unless it's for a collection or you have a large lot of the same part number to do. A more useful data is by testing a good cross section of what you will be working with. If you ask someone that has already put in the time, "how much gold can you get from this many of this type chip", the answer would be meaningless to you.

 

[Stowmaster]

My experiment with 500 g of chips of mobile phones.
Procedure:
1) removed all the solder.
2) chip burned and milled in a coffee grinder.
3) dissolved base metals and held flotation
Under magnification gold threads I dont see. Only yellow sand and a slightly fragments of crystals. Weight 1.7 g

https://www.dropbox.com/s/ieftb5kmpspyka3/3.1.jpg

4)Burned chips without base metals sent to aqua regia. Result of the third part of the experiment delayed.

 

[Geo]

After milling the chips, the gold bonding wires will not look like wires. It will look more like what you have. The picture is very fuzzy but the yellow is unmistakable.

 

[patnor1011]

Coffee grinder will do quick job with gold wires. It will turn them to gold powder.

 

[Stowmaster]

I made a better quality photo
https://www.dropbox.com/s/ji17gur5rv6935f/3.1.1.JPG

 

[g_axelsson]

I made a better quality photo
https://www.dropbox.com/s/ji17gur5rv6935f/3.1.1.JPG

Obviously that isn't gold, just a lot of trash. It could have some gold hidden though.

I would add some AR (Cover it in HCl and add a few drops of HNO₃) and then test the solution with stannous. 1.7g of material wouldn't need any more than 1.7 ml HNO₃ at the most if it was pure gold. If you get gold in solution, then filter it and either save it or drop it with a little bit of SMB.

What do you mean with "3) dissolved base metals and held flotation"? Gold can easily float on surface tension. What acid did you use for dissolving base metals?

Göran

 

[patnor1011]

It may be gold. I have seen it many times that gold got dirty look with this process. All he need to do to be sure is just to wash that material in straight nitric first. Then use AR and proceed from there.

But Goran is asking some valid questions.

 

[Stowmaster]

I made a better quality photo
https://www.dropbox.com/s/ji17gur5rv6935f/3.1.1.JPG

Obviously that isn't gold, just a lot of trash. It could have some gold hidden though.

I would add some AR (Cover it in HCl and add a few drops of HNO₃) and then test the solution with stannous. 1.7g of material wouldn't need any more than 1.7 ml HNO₃ at the most if it was pure gold. If you get gold in solution, then filter it and either save it or drop it with a little bit of SMB.

What do you mean with "3) dissolved base metals and held flotation"? Gold can easily float on surface tension. What acid did you use for dissolving base metals?

Göran

I used about 23% nitric acid solution. I dilute 70% nitric acid rainwater.
This powder is precipitate at bottom of the jar.
In aqua regia (more precisely - in SSN), I put all, except this powder.

updated: Only considering density, I can confidently say that there more than 1 gram of gold.
updated2 added foto https://www.dropbox.com/s/hh9kp5lxqhvbxii/3.2.JPG

 

[patnor1011]

I dont understand if you just washed it in nitric how come that you have any precipitate at bottom. Perhaps you used wrong term. I am no expert in SSN and never did that so I cant be of any help there.

 

[Stowmaster]

Maybe I'm incorrectly to use the term flotation. Maybe somewhere error interpreter.
Sequence of my actions:
1) 500 grams of chips I filled 23% nitric acid for 2 days.
2) Brushing I cleaned the remains of tin acid.
3) I manually separated useless phragments of chips.
4) Chips I burned. Chips burned very well.
5) I burned chip grind in a coffee grinder.
6) I milled chip on 2 days filled 23% nitric acid. Several times a day mixed. Purpose - the dissolution of base metals.
7) I poured the contents of the jar onto the filter. Powder on the photo stayed at the bottom jar. I do not know how it happened. I did not plan this event. But I remember the technique of mixing in paragraph 6. I made ​​a circular motion relatively the plane of the earth, holding the jar in hand. I think that there was a natural gravity separation.
8. The filtrate is washed with water and i added SSN - 30 ml of 70% nitric acid, 60 g of crystalline NaCl for 2 days. Several times a day mixed.
9) I added water, dissolved salt residue and the mixture was filtered. Then I washed several times with the filtrate.

 

[Geo]

Maybe I'm incorrectly to use the term flotation. Maybe somewhere error interpreter.
Sequence of my actions:
1) 500 grams of chips I filled 23% nitric acid for 2 days.
2) Brushing I cleaned the remains of tin acid.
3) I manually separated useless phragments of chips.
4) Chips I burned. Chips burned very well.
5) I burned chip grind in a coffee grinder.
6) I milled chip on 2 days filled 23% nitric acid. Several times a day mixed. Purpose - the dissolution of base metals.
7) I poured the contents of the jar onto the filter. Powder on the photo stayed at the bottom jar. I do not know how it happened. I did not plan this event. But I remember the technique of mixing in paragraph 6. I made ​​a circular motion relatively the plane of the earth, holding the jar in hand. I think that there was a natural gravity separation.
8. The filtrate is washed with water and i added SSN - 30 ml of 70% nitric acid, 60 g of crystalline NaCl for 2 days. Several times a day mixed.
9) I added water, dissolved salt residue and the mixture was filtered. Then I washed several times with the filtrate.

8. The filtrate is washed with water and i added SSN - 30 ml of 70% nitric acid, 60 g of crystalline NaCl for 2 days. Several times a day mixed. Here is where your gold is hidden. Do you still have the SSN from step 8? Did you test the SSN with stannous chloride for the presence of gold?

Everything solid after step 8 should be trash and there should be no solid gold after step 8.

 

[Stowmaster]

Here is where your gold is hidden. Do you still have the SSN from step 8? Did you test the SSN with stannous chloride for the presence of gold?
Everything solid after step 8 should be trash and there should be no solid gold after step 8.

Sand, which remained at the bottom of jar (step 7) on the picture 3.1. https://www.dropbox.com/s/ji17gur5rv6935f/3.1.1.JPG I left "as is." At this moment I did not process it. Maybe I'll leave it as a souvenir. Maybe melted without processing. In step 8 was sent to all, except the sand
The result of processing in the steps 8-9 on the photo 3.2 https://www.dropbox.com/s/hh9kp5lxqhvbxii/3.2.JPG in jars (currently precipitated SMB).
That's not all. Burned chips the second time I burn and filled SSN...

Added photo 3.3 https://www.dropbox.com/s/dvxlc38l0asd98w/3.3.JPG First fraction after SMB. Precipitation time about 150 minutes. Сolor is not very good.

 

[Geo]

Ok, so the yellow solids is more than likely gold and you successfully leeched the remainder. It was successful because you dropped the gold with SMB. So basically, you are outlining the process you used to get what you have. I thought you were asking a question. Try refining the dark powder again so that it resembles clean gold powder.

 

[jason_recliner]

Hi Pat
I've just found this thread and downloaded your PDF from page 3. (I've not gone through all 28 pages of this thread.) It's very nicely documented.

I just want to slap myself.

About eight months ago, before I found this forum, I went through a couple of kilograms of old RAM sticks (as old as 30 pin, 72pin), ISA cards, 386 motherboards and the like. I'd been hanging onto them at work since 1988 in case we needed to service a machine that only ran on a 386 and 387 and finally we were done with it. I collected everything gold coloured, trimmed the fingers nicely and went about my first recovery. The rest went in the bin.

I'll bet that old stuff was loaded with much thicker gold than we find now...