My results of specific types of IC chips, flatpacks and BGA

[Rreyes097]

So the legs that you cut off with scalpel , you save those and process those by themselves using nitric? The AR?

 

[Rreyes097]

This is my little contribution to the site, I have tested various types of chips for gold content using these steps:
1. Separation of the specific type of chips, removing paper stickers if any, removing wires from the edges of the chips with scalpel (*some types of chips are processed along with these wires and that will be indicated), weight them, and count the pieces of chips included.
2. Pyrolizing chips with butane torch.
3. Turning chips to ash on a hotplate
4. Shaking the chips inside of the glass jar and sieving the ashes
5. Repeating steps 3-5 until all of the white/grey powder goes through the sieve, and the resin consists of wires, silicon dies and heat spreaders
6. Washing with hot water until water is clear
7. Removing magnetic wires with neodymium magnet while still inside in water (*these wires are processed separately, I remove the basic metals with nitric acid and process them with aqua regia, for every 5kg of all kind of chips I recover 2-3 grams of gold only from these wires, so all of my results are not including gold from these wires, and not including the gold from the resins-wires, silicon dies and heat spreaders, it only relates to sieved ash).
8. Remove the basic metals from concentrate with nitric acid and washing again with water
9. Aqua regia, neutralizing excess nitric with urea, dropping the gold with SMB.
10. washing the gold powder 3xdistilled water 3xHCl, 3xdistilled water.
11. Weighting the gold and calculating the percentage of gold yields by kg of specific chips and even the gold yield of one piece of specific chip.

I will post one by one type of chips. This is a first type - SMALL VARIOUS CHIPS. You can see on the pictures shapes and the size of these chips. They have at least 6 wires, some of them are thinner then the others, also some of them are square and have wires of all 4 sides. Since their size are similar and very small, I decided to classify them as small various chips and process them together. Because they are very small I have not removed the wires.
View attachment 30247
View attachment 30246
The total weight is 747g, there are 6317 of chips, and the gold recovered was 1.0g.
Conclusion is:
1kg of small various chips contains 1.338688g of gold. (only from ash, not including magnetic wires with gold bonding wires trapped inside of them and resins-wires, silicon dies and heat spreaders)
Average weight of one chip is 0.118252335g.
Average gold content by one chip is 0.000158303.

So how do you process the metal you take out?

 

[Martijn]

So the legs that you cut off with scalpel , you save those and process those by themselves using nitric? The AR?

The wires are the basemetal legs. Scrap.

 

[Rreyes097]

The wires are the basemetal legs. Scrap.

Doesn't it say that the wires that are taken out are processed separately? Please read#7

 

[Rreyes097]

So the legs that you cut off with scalpel , you save those and process those by themselves using nitric? The AR?

Didn't realize I posted about that already my apologies. I guess I'm just reading it wrong.

 

[Rreyes097]

I figured it out. I had to go back and read some posts over again a few times more. Thanks

 

[Martijn]

I figured it out. I had to go back and read some posts over again a few times more. Thanks

Happens to all of us.
He describes how the by neodynium magnet separated wires are processed in step 7: nitric bath followed by an AR bath. He does the same on the resin concentrates which contain the bulk of the gold in step 8 and 9.
He gets 2-3 grams of gold per 5 kilo of pins from the magnetic wires.

Here is something to consider though: To dissolve 5kg of basemetals in nitric to yield 3 grams of gold is creating a lot of waste and using nitric.
As far as i understood: For one gram of copper to dissolve takes about 4ml of nitric. How that ratio is with (kovar?) wires, no idea. But if you take that number, and my calculation is correct, for 5kg that would mean 20 liters of HNO3 is needed to get about 3 grams of gold. Diluted with eaqual parts water.
Depending on what nitric costs you, profit gone?
And buckets full of carcinogenic nickel salts. About 40 Liters.
Decide if thats worth chasing for you first.
And that us his number of recovery, with his processes. Yours could be lower or higher.

I would try AP, the slow and cheaper method, on some of the wires to see if that dissolves the pins. Still a lot of toxic waste to deal with. There are other ways to get the gold. Some leave the base metals intact.
Most is discussed somewhere in this thread, but its has become a very long read of 500 posts.

Martijn.

 

[Rreyes097]

Yes extremely large post. Thanks to me, for I didn't understand for so long. I now understand that the point of the ball mill wasn't simply to break open the chip but to also get the gold wires free of the basemetal and silicon dies. I just kept noticing what looks like gold plating on some of this metal. And so I wasn't sure. But I think I've got it now. Thanks!

 

[orvi]

Not worth the acid treatment, only in a way of stripping the gold selectively over the base metal.
More viable would be lead-dip gold stripping. Or bismuth-dip, if you feel more "eco"

Iron or nickel has poor solubility in aforementioned metals at low temperatures, whereas gold is nicely soluble. Hot tumbler is the thing you want - operating at some 300-400°C, in reducing atmosphere or with addition of some reducer to combat surface oxidation of molten Pb/Bi.

Yeah, you does not get all of the gold. Some will stick to the legs of course, but you can minimize that by good shaking through stainless steel mesh with simultaneous heating. It is a big difference to get 80% of gold ending up in few hundred grams of lead/bismuth, than to treat these 5kg of legs with AP or AR to produce 20+L aqueous waste - which is relatively toxic due to nickel. Not to mention the cost of that ammount of acids.

Cupel the Bi/Pb away to be left with the PM bead. Of course, some deposition of NiO and Fe2O3 would be seen, but overall, if you keep temperature below 400°C during the stripping, co-dissolution of Fe/Ni wouldn´t be that significant. Alternatively, if you somehow screw this up, you can cupel that away to the point it will go, and then dissolve the residue directly in AR (if not much lead will be left). In case of higher silver content, inquart it right away and part in nitric.

 

[Rreyes097]

Not worth the acid treatment, only in a way of stripping the gold selectively over the base metal.
More viable would be lead-dip gold stripping. Or bismuth-dip, if you feel more "eco"

Iron or nickel has poor solubility in aforementioned metals at low temperatures, whereas gold is nicely soluble. Hot tumbler is the thing you want - operating at some 300-400°C, in reducing atmosphere or with addition of some reducer to combat surface oxidation of molten Pb/Bi.

Yeah, you does not get all of the gold. Some will stick to the legs of course, but you can minimize that by good shaking through stainless steel mesh with simultaneous heating. It is a big difference to get 80% of gold ending up in few hundred grams of lead/bismuth, than to treat these 5kg of legs with AP or AR to produce 20+L aqueous waste - which is relatively toxic due to nickel. Not to mention the cost of that ammount of acids.

Cupel the Bi/Pb away to be left with the PM bead. Of course, some deposition of NiO and Fe2O3 would be seen, but overall, if you keep temperature below 400°C during the stripping, co-dissolution of Fe/Ni wouldn´t be that significant. Alternatively, if you somehow screw this up, you can cupel that away to the point it will go, and then dissolve the residue directly in AR (if not much lead will be left). In case of higher silver content, inquart it right away and part in nitric.

I have no idea how to do any of that. I don't have 5kg of the stuff but perhaps a pound of it so far. But I understand that I won't get the gold off of it. I accept that

 

[Yggdrasil]

I have no idea how to do any of that. I don't have 5kg of the stuff but perhaps a pound of it so far. But I understand that I won't get the gold off of it. I accept that

Somebody in here said they just put it outside in the Weather and let it rust, after a few years most is gone by mother nature.
Clean it and check it from time to time.

 

[Rreyes097]

Somebody in here said they just put it outside in the Weather and let it rust, after a few years most is gone by mother nature.
Clean it and check it from time to time.

I guess that's one way of doing it. It is hard for me to know that there's gold in there but not able to get to it.

 

[BlackLabel]

Bucket, AP solution, waiting?

 

[gfusc]

Any results from the telecom boards posted earlier?

 

[Yggdrasil]

Any results from the telecom boards posted earlier?

There should not be any telecom boards here. This thread is about ICs
Did you see telecom boards in this thread?

 

[Yggdrasil]

Any results from the telecom boards posted earlier?

I see now there is mention of telecom boards by the OP.
But he process only the ICs here if I understand it correctly so the numbers will not be representative for the whole board.

 

[Nickperl]

Nickperl, thank you for sharing your results. There could be many reasons why the results are varying, some of them are:
1. If you have a pile of all kind of BGA chips (only PLASTIC tops, there are no ceramic BGA chips as i know) there is a big difference between the ones with and without internal heatsink, the more of chips with internal heatsinks you have - the less gold per weight there will be. I am intending to test them separately one day.
2. When you sieve the chips, the longer gold bonding wires will get tangled together and will not go through the sieve, on the first picture there is that residue that didn't gone through sieve, the tangled gold bonding wires are visible with naked eyes, on the second picture are the same gold bonding wires - magnified. Make sure to when processing BGA chips, all of that residue mix together with your concentrate (previously washed with water) and then continue with nitric acid or whatever process you are using, Before everything, when chips are burned i am only remove the internal heatsinks, everything else goes to process, and this steps only relates to BGA chips since they do not have any magnetic metals, they also have very little basic metals.
View attachment 30560
View attachment 30561
3. The results may varying because the chips are not burned to ash as well, i do not use mortar and pestle, i just shake them in jar and the parts that stays hard, i burn them again until they all becomes white and soft, that way there is less risk that gold bonding wires stays trapped inside of unburned clumps of plastic chips.
4. maybe you processed everything well and that is a true yield for that chips, there are many types of BGA chips and the yield is depending of type, where are they built, when are they built, etc.

I don't know the exact yield of green fiber bases, i tried once to process them, and obtained a very little of gold, about 0.1g for a bunch of them.

"PROBLEM. Any time I use the AR the solution always has GREEN in it. The only yellow AR I get is when I'm processing gold soaked from china and dishware using Acid-peroxide process)."
That means you still have the basic metals inside of solution, when you (before AR) properly process the material with nitric acid (and washed with dist. water) there should be no green/blue color or very little in your AR solution.

Hi Tzoax! I hope you're still active after the eight years since you responded to my project. Looks like I never thanked you. Thank you! Now, here in April, 2023, I'm again processing ic chips, regular this time. And I have a dirty green Auric Chloride - again. So I'm going to again refine my refining process and re-learn the proper ways of processing. Thanks, again. I do appreciate the work you took to respond. Nick

 

[Yggdrasil]

Hi Tzoax! I hope you're still active after the eight years since you responded to my project. Looks like I never thanked you. Thank you! Now, here in April, 2023, I'm again processing ic chips, regular this time. And I have a dirty green Auric Chloride - again. So I'm going to again refine my refining process and re-learn the proper ways of processing. Thanks, again. I do appreciate the work you took to respond. Nick

Tzoax was here the last time 29th of June 2021.
I hope he will turn up again.

 

[Nickperl]

Tzoax was here the last time 29th of June 2021.
I hope he will turn up again.

Thanks Ygg for responding. His advice is again coming in handy.

 

[J.Najam]

Hello again everyone,

First of all I'd like to thank the OP @Tzoax for your tremendous work and contribution in correlation to this thread. Your time, effort, energy and the intricate detailed information posted by you to enhance our knowledge here is priceless and I along with others hope to see you back soon.

I do have many questions but I'll save them for later on, for the time being, below mentioned is a type of chip that I'm about to acquire but the seller wants me to give him the best price. I went through this post for processing IC chip clarification ( after patnor, kurtak remaining) and found the chip encircled in red close to what I am being given. I haven't ever done these but unfortunately I couldn't quite find the correct data for recovery in the pdf that I've attached with this post too. As far as I understand and please correct me if I'm wrong, based on the earlier experiments by the OP, that I can quote a price based on the average as mentioned? Or if someone out there has actually done these can provide a direct number for a better yield prospect hence giving a fair quote up ahead.

From left,

XILINX 1 and 2 are being sold, seller asks for price.
XILINX 3 is what I found in of the posts.

PS. does the speed mean anything in recovery? The speed mentioned on his chip is 15 C and the one I've posted is 7 C.

Thanks in advance.