# IC chips gold recovery



## sayf (Sep 26, 2022)

Hello dear refiners, i hope you are all fine.
I have a good source for E-waste so i can collect good amounts of ic chips.
most of the E boards i usually get are communication boards.
The first patch of ic chips i did was about 20 kg 
I incenerated the chips, powdered them then i carefully washed the powder to get rid of epoxy, then i get rid of the basic metals using 1-1 diluted nitric acid 
I precipitated the silver from the nitric using nacl solution and got good amount of silver exceeding 100 grams 
For the rest of the process, i washed the leftovers using distilled water and added aqua regia to the leftovers, i made sure that the amount of aqua regia is enough to dissolve all the metals and i wated until the reaction is completely done
I nutrelized the nitric with sulphamic acid and precipitated gold using ferrous sulphate
And got only 4 grams of gold, duh i was shocked because i expected more than 40 grams of gold.
the second patch was also 20 kg and was done using same procedure and got similar result 
Do you think this result is logical dear experts?
The electronics i deal with are old and mostly simens and alcatel 
What i am missing here ?
REGARDS


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## Yggdrasil (Sep 26, 2022)

sayf said:


> Hello dear refiners, i hope you are all fine.
> I have a good source for E-waste so i can collect good amounts of ic chips.
> most of the E boards i usually get are communication boards.
> The first patch of ic chips i did was about 20 kg
> ...



First of all it is *NOT NEUTRALIZING THE NITRIC*, it is decomposing, out gassing, destroying or similar.
Because what you do is to change the Nitric and NOx to other harmless (for the coming reactions) substances.
We have replied to you in this matter several times.

Why did you have to get rid of epoxy, was it not completely incinerated?
Was ALL the metals dissolved after AR?
Did you test the solution after Copperas?


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## kurtak (Sep 26, 2022)

First off - if you are processing "a good mix" (all types) of ICs you should most certainly get MUCH more the 4 grams gold from 20 kg chips

To put it in perspective - if you processed NOTHING BUT 20 kg of PROMS (the very lowest grade of chips) then yes you would only get (about) 4 grams 

But a true "mix" of chips should give you better (much better) results

This thread should give you "an idea" of what to expect from "each type" of chip(s)









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


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...




goldrefiningforum.com





That said ------


sayf said:


> I incenerated the chips, powdered them then *i carefully washed the powder* to get rid of epoxy, *then* i get rid of the basic metals using 1-1 diluted nitric acid



Per the bold print - this IMO (In My Opinion) is your first mistake !!!

You *first* NEED to get rid of the base metals BEFORE washing of the ash/carbon (after incinerating & milling/crushing) --- as well as larger pieces of broken silicon dies

If you don't get rid of the Kovar &/or copper legs/wires (as well as silicon dies) in the carbon/ash BEFORE trying to wash off the carbon/ash - those Kovar/copper legs/wires & large pieces of silicon dies will cause interference in the washing process which will in turn cause the *VERY fine* gold bonding wires to wash off along with the carbon/ash

So the proper steps are as follows ------

1) incinerate to turn the epoxy to carbon/ash

2) mill/crush the carbon/ash (incinerated chips) to fine powder

3) sift the milled chips (carbon/ash) through (at least) 80 mesh (or 100 mesh) screen which will remove the "larger" Kover/copper & larger pieces of silicon dies --- smaller Kovar/copper wires (& fine crushed silicon) will go through the sifting screen - so -----

4) spread out the (fine milled) carbon/ash in a *very thin* layer & run a "weak" magnet over it to remove any Kovar that made it through the sifting screen --- there will still be fine copper in the carbon/ash which you need to get rid of

Depending on how much copper is in carbon/ash you may have to ---------

1) leach/dissolve the copper out of the carbon/ash BEFORE washing the carbon/ash off to collect/concentrate the gold bond wires --- or ------

2) you MAY get away with doing a "pre-wash" of the carbon ash - to "reduce" the amount of carbon/ash before leaching/dissolving the copper - then a second wash to collect/concentrate the bond wires

There are a couple different method to the above step 2 depending on the amount of copper in the carbon ash

Bottom line - you want to get rid of as much "junk" from the carbon/ash BEFORE washing the carbon/ash to concentrate the bond wires for final leaching or smelting

The trick is leaving the gold in the carbon/ash during the process of removing the junk

if you don't remove the junk (at least the LARGE Kovar/copper/silicon) you will most certainly wash gold (bond wires) out with the carbon/ash

Kurt


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## Martijn (Sep 26, 2022)

sayf said:


> Hello dear refiners, i hope you are all fine.
> I have a good source for E-waste so i can collect good amounts of ic chips.
> most of the E boards i usually get are communication boards.
> The first patch of ic chips i did was about 20 kg
> ...


Aluminum bonding wires in most of them in stead of gold maybe? Did you sort any of the IC's or did you process everything together? 
Incinerate a couple and inspect with a jewelers loupe or microscope. Saves a lot on burning waste, and consuming base metals with nitric to get 'worthless' aluminum wires. 
How did you minimize the NO2 emissions? 

20kg's of chips burned. Can you share pictures of your pyrolyzing and incinerating setup? 
Did you have different results with these types of chips before or with any chips?
I'm trying to asses your level of experience in keeping the toxic stuff out of your lungs and our environment.

Edited for spelling.
And:
I know you tube is by-passing us in this but i really must warn you for the dangers of burning epoxy, PVC, and other plastics. 

To me it sounds like you don't fully grasp the whole process yet, but felt confortable enough processing a bucket full of mixed stuff you've never done before. 

Experiment small, you'll have small mistakes to clean up with big experience steps. 
Once you have it down, scale up. Slowly. 

Martijn.


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## kurtak (Sep 26, 2022)

Martijn said:


> Experiment small, you'll have small mistakes to clean up with big experience steps.
> Once you have it down, scale up. Slowly.


I agree !!!!



Martijn said:


> Can you share pictures of your pyrolyzing and incinerating setup?


It would also be good to see pics of the actual chips (at least a small sample of the "types" of chips) & as well pics of your washing set up

Kurt


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## Martijn (Sep 26, 2022)

kurtak said:


> It would also be good to see pics of the actual chips (at least a small sample of the "types" of chips) & as well pics of your washing set up
> 
> Kurt


Yes. I agree. 

But he may have lost gold due to inexperience, and mistakes in processing.

Then I would like to encourage him to maximize the efficiency of his entire process, by looking at what is worth processing and what simply is a waste of 
time and resources. 
It's like finding a rich ore and mixing it with workshop grindings before recovering values. 
Junk in, junk out, so don't add any more junk. 
It's like inquarting gold plated copper with more copper just to dissolve the whole thing... 

First stip that 100 feet of overburden before you sluice. Saves on


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## kurtak (Sep 26, 2022)

Martijn said:


> Then I would like to encourage him to maximize the efficiency of his entire process, by looking at what is worth processing and what simply is a waste of
> time and resources.


I agree - which is why pictures of the different stages/step of his process would be good to see

Pics off -----

1) the chips them selves

2) incineration set up

3) milling/crushing set up

4) sifting/magnetic separation process

5) washing setup/process

6) leaching process

Kurt


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## orvi (Sep 26, 2022)

If leaching is applied on large bulk of fine ground ash/silica powder, great care should be taken to burn ALL of the carbon from it. Carbon has quite concerning loading capacity for adsorption of dissolved metals, particularly gold. 
I like to take red hot pyrolyzed/half-incinerated remains of ICs out of the furnance and spread them onto some plate (old baking pan etc.) which is insulated to retain heat from the bottom. Then I take heatgun and blow hot air on them to properly burn out all of the carbon to be left with only slightly greyish material which easily crumbles to the powder when simply shaken in some container.

Thing is, inside the furnance when heating with burner, there is always low oxygen atmosphere due to this obvious fact. Taking them out and spreading them into some thin layer assures air (not combusted gasses) will reach them properly and finish the incineration relatively quickly. 

Alternatively, you can do whole incineration with heat gun instead of the burner, if it can get to like 600°C. Air isn´t deprived of oxygen (like with torch), so when the temperature rise and burning kicks in, it is burning much much cleaner than with torch heating. But also afterburner should be installed anyway to deal with some remains of uncombusted material. Of course, I am speaking about incineration inside gas furnance.

With bulk of the ashes, sifting and careful panning/sluicing is an option. But if it isn´t very big volume, I like to briefly remove magnetics out and smelt it all down. Powder is practically plain silica, so CaO flux, induction furnance, 1300-1400 °C and it is done conveniently and quantitatively.


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## sayf (Sep 26, 2022)

kurtak said:


> First off - if you are processing "a good mix" (all types) of ICs you should most certainly get MUCH more the 4 grams gold from 20 kg chips
> 
> To put it in perspective - if you processed NOTHING BUT 20 kg of PROMS (the very lowest grade of chips) then yes you would only get (about) 4 grams
> 
> ...





kurtak said:


> First off - if you are processing "a good mix" (all types) of ICs you should most certainly get MUCH more the 4 grams gold from 20 kg chips
> 
> To put it in perspective - if you processed NOTHING BUT 20 kg of PROMS (the very lowest grade of chips) then yes you would only get (about) 4 grams
> 
> ...


Thank you very much kurt, you are alright and most likely i lost the gold bonding wires during the wash step.

Because i just finished a patch of 10 kg ic chips of almost same type as the above 20 kg patch using chemical wet ashing method and got 19 grams of gold


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## kurtak (Sep 27, 2022)

orvi said:


> If leaching is applied on large bulk of fine ground ash/silica powder, great care should be taken to burn ALL of the carbon from it. Carbon has quite concerning loading capacity for adsorption of dissolved metals, particularly gold.



This is correct - dissolved metal ions like to "load" (absorb) on fine particles of carbon which will lead to lost gold in the leaching process if the fine carbon is not turned to actual ash *before* leaching the gold from the concentrates

In fact "carbon loading" is one way to recover dissolved metal ions from a solution - but that is a whole different process for a whole different discussion


orvi said:


> I like to take red hot pyrolyzed/half-incinerated remains of ICs out of the furnance and spread them onto some plate (old baking pan etc.) which is insulated to retain heat from the bottom. Then I take heatgun and blow hot air on them to properly burn out all of the carbon



As the saying goes --- there is more then one way to skin a cat  

That said - you do not need to be concerned with turning *the whole chips* to ash - you only need to be sure that the chips are *completely carbonized* so that they can be milled to a fine powder (80 - 100 mesh)

Once the carbon is milled to a fine powder & after sifting & magnetic separation (as described yesterday) to remove the "large" pieces of Kovar/copper & broken silicon dies you can then go to the washing process to get you concentrates

Carbon that is milled to 80 (minus) mesh is very light weight & will wash off just fine - to give you the concentrates you are after

Yes - the concentrates are going to have carbon in them (as well as fine silicon & fillers used in the epoxy) but that is as simple as re-incinerating those concentrates to turn that *small amount* of carbon to ash before leaching the concentrates 

IMO - it is much easier to just get the chips completely carbonized - milling the carbon - do the concentration process - then re-incinerate the concentrates to insure the carbon is turned to ash --- rather then trying to incinerate whole chips to complete ash before milling & concentrating

In fact - it is next to imposable to completely ash whole chips - especially if you are doing larger batches (20 - 30 kg) & or if you have thick chips (like PROMs &/or thick quads) in the mix --- you are likely going to end up with carbon in the concentrates anyway which means the concentrates will need re-incineration anyway

This is based on my doing 25 - 35 kg batches at a time with doing 200 - 300 kg of chips per year 

Carbonize (completely) mill carbon to fine powder - sift/magnetic separation - concentrate - re-incinerate concentrates - leach (or smelt) concentrates

In other words - there is no need to be concerned about carbon when processing IC chips --- until you get to the point of leaching (or smelting) the concentrates

IMO 

Kurt


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## kurtak (Sep 27, 2022)

sayf said:


> Because i just finished a patch of 10 kg ic chips of almost same type as the above 20 kg patch using chemical *wet ashing method* and got 19 grams of gold


Per the bold print - IMO - *only a fool would use that process* - especially when trying to process chips in large batches with the wet ashing process 

Yes I have used that process - *one time *- & I will *NEVER* do it again because I am not a fool

Learn to do it through the proper incineration process

Kurt


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## kurtak (Sep 27, 2022)

orvi said:


> With bulk of the ashes, sifting and careful panning/sluicing is an option. But if it isn´t very big volume, I like to briefly remove magnetics out and smelt it all down. *Powder is practically plain silica*, so CaO flux, induction furnance, 1300-1400 °C and it is done conveniently and quantitatively.


Per the bold print - after milling the IC chips you end up with (at least some) *silicon* in the ash - silicon will in fact alloy with gold - so yes - if you are going to smelt you need to have lime in the flux to insure the silicon slags off & does not alloy with the gold --- it (lime) of course helps with the silica as well - the silica comes from the fillers used in the epoxy

Kurt


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## kurtak (Sep 27, 2022)

Some pics of when I was processing larger batches of IC chips - notice that the fine powder after milling is very near entirely fine carbon - which I did not concern myself with until after washing to get my concentrates


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## kurtak (Sep 27, 2022)

Magnetic separation - note the carbon is spread very thin on a non magnetic SS sheet (sorry no pics of sifting)

I wrap a plastic bag around the magnet to make it easier to remove the Kovar that is stuck to the magnet by simply pulling the plastic away from the magnet when the magnet is loaded with Kovar


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## Shark (Sep 27, 2022)

Please note Kurt’s use of gloves while using the magnet.


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## kurtak (Sep 27, 2022)

After sifting & magnetic separation I run the fine carbon on my concentrator table to wash off most of the fine carbon

Most of the gold bond wires collect at the top of the table

Some carbon along with fine ground silicon & fillers from the epoxy as well what very few bond wires make it past the top of the table collect further down the table --- what collects on the table is your concentrates

20 - 25 kg of starting chips should give you (about) 1/2 to 2/3 of a 20 liter bucket full of fine milled carbon

when you are done concentrating you should end up with 3 - 4 cups (5 cups at most) of concentrates - which then need to be re-incinerated to ash the carbon

Sorry I only have pics of the bonding wires colleting at the top of the table but no pics of the silicon/filler/carbon that collects further down the table


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## kurtak (Sep 27, 2022)

Shark said:


> Please note Kurt’s use of gloves while using the magnet.


Yes - there is all kinds of nasties in that fine ash/carbon

Edit to add; - in fact I wear gloves in *EVERY step* of the process from incineration to the end product of the recovered/refined gold

Edit again to add; - when milling & handling the dry carbon you MUST also wear a good dust mask

There is ultra fine silica in the fine carbon powder & if you breath that ultra fine silica into you lungs it will more then likely result you getting silicosis - which you will not even know you have until years later 









Silicosis - Wikipedia







en.wikipedia.org





Kurt


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## kurtak (Sep 27, 2022)

Finished product after all is said & done


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## MicheleM (Sep 27, 2022)

Thank you for sharing your work @kurtak. 
i have not more IC to have fun with so I can only appreciate this kind of pictures: good moments come back in my mind


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## sayf (Sep 27, 2022)

kurtak said:


> Finished product after all is said & done


Just a curious question, after milling the ic chips to a very fine powder and incinerating the black powder again to make sure that all carbon is gone, can i use aqua regia directly to dissolve all metals and after making sure that all metals are dissolved ill filter the solution and drop dirty gold with ferrous sulfate then ill purify the gold again using a second aqua regia dissolve and drop it with ferrous sulphate .
Is this possible ?


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## kurtak (Sep 28, 2022)

sayf said:


> Just a curious question, after milling the ic chips to a very fine powder and incinerating the black powder again to make sure that all carbon is gone, *can i use aqua regia directly to dissolve all metals *and after making sure that all metals are dissolved ill filter the solution and drop dirty gold with ferrous sulfate then ill purify the gold again using a second aqua regia dissolve and drop it with ferrous sulphate .
> *Is this possible ?*



Per the bold print - short answer = yes (it's "possible")

Longer answer = it is *NOT* a good idea - in fact it is a *VERY* bad idea !!!

Why?

1) it will create a *LOT* of chemical waste *!!!* --- chemical waste that you absolutely DO NOT need to create *!!!*

2) Kovar - which is what most of the base metal in IC chip ash is - is *VERY* acid resistant & requires LOTS of heat for the acid to dissolve the Kovar

3) Even with HOT acid it will take longer (a LOT longer) to dissolve the Kovar out of the ash then the time it takes to pull the Kovar out of the ash with a magnet

Kurt


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## sayf (Sep 28, 2022)

kurtak said:


> Per the bold print - short answer = yes (it's "possible")
> 
> Longer answer = it is *NOT* a good idea - in fact it is a *VERY* bad idea !!!
> 
> ...


Thank you very much kurt, Here are the IC chips i mostly work with


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## jphayesjr (Sep 28, 2022)

sayf said:


> Just a curious question, after milling the ic chips to a very fine powder and incinerating the black powder again to make sure that all carbon is gone, can i use aqua regia directly to dissolve all metals and after making sure that all metals are dissolved ill filter the solution and drop dirty gold with ferrous sulfate then ill purify the gold again using a second aqua regia dissolve and drop it with ferrous sulphate .
> Is this possible ?


Read Hoke's book


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## goldeelox (Sep 28, 2022)

kurtak said:


> After sifting & magnetic separation I run the fine carbon on my concentrator table to wash off most of the fine carbon
> 
> Most of the gold bond wires collect at the top of the table
> 
> ...


You using a Freddy dodge table


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## BlackLabel (Sep 28, 2022)

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From Keene Engineering:








Gold Magnet: Keene Engineering Online


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www.keene.store














The Big Orange Gold Magnet: Keene Engineering Online


SEO: META DESCRIPTION



www.keene.store





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## snoman701 (Sep 28, 2022)

Hope you saved your ash. Your gold is still there. Just do what Orvi suggested. Put it all out in a thin layer and put it in a furnace at 650 deg C util your ash is a whitish purple. 

However, if you used aqua regia on it, you should first wet it all with water that has a pH of 11 or so. This will keep your vaporization losses lower. 

Once ashed out, you can use HCl with stepwise additions of nitric or peroxide to dissolve your gold. You'll lose some gold to the ash, just because you can never actually rinse it clean of values...but it's saveable. 

Your gold is going to be too finely divided to be gravity separated at this point. That's the only reason I suggest going straight to chemical leaching.


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## Rreyes097 (Oct 1, 2022)

orvi said:


> If leaching is applied on large bulk of fine ground ash/silica powder, great care should be taken to burn ALL of the carbon from it. Carbon has quite concerning loading capacity for adsorption of dissolved metals, particularly gold.
> I like to take red hot pyrolyzed/half-incinerated remains of ICs out of the furnance and spread them onto some plate (old baking pan etc.) which is insulated to retain heat from the bottom. Then I take heatgun and blow hot air on them to properly burn out all of the carbon to be left with only slightly greyish material which easily crumbles to the powder when simply shaken in some container.
> 
> Thing is, inside the furnance when heating with burner, there is always low oxygen atmosphere due to this obvious fact. Taking them out and spreading them into some thin layer assures air (not combusted gasses) will reach them properly and finish the incineration relatively quickly.
> ...


Would an electric furnace work in a crucible?


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## Yggdrasil (Oct 2, 2022)

Rreyes097 said:


> Would an electric furnace work in a crucible?


I guess you mean the opposite?
Would a crucible work in an electric furnace?
Yes most small ones will come with a graphite crucible.


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## Rreyes097 (Oct 2, 2022)

Yggdrasil said:


> I guess you mean the opposite?
> Would a crucible work in an electric furnace?
> Yes most small ones will come with a graphite crucible.


What I meant was can I put ic chips in the electric furnace crucible and paralyzing like that instead of torching them because the stank and the smoke is too much for the area I live in.


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## Yggdrasil (Oct 2, 2022)

Rreyes097 said:


> What I meant was can I put ic chips in the electric furnace crucible and *paralyzing* (*pyrolizing*) like that instead of torching them because the stank and the smoke is too much for the area I live in.


That is not *pyrolizing, *it is incineration. 
Pyrolizing is heating it up without access to air until all volatile elements has evaporated and burnt up in a afterburner.
Usually this is done in an coal/gas furnace where the gases are lead into the heating burner, 
this reduces the needs for fuel and will burn all gases completely eliminating smoke and smell.
The left overs has to be incinerated/roasted in air after to completely burn off the carbon residue.


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## Rreyes097 (Oct 2, 2022)

So i have those Ic chips that came off of the ram sticks. These chips (forgive me because I don't know the actual nes for these) so I have no real base metals to worry about. I have already washed them I'm hot HCl 3 times, then rinsed with water until my rinses were pretty clear. So which process do I need to do? Pyrolyzation or incineration? I tried to just burn a pan of them with a torch.
It let off far too much smoke of nasty smell. So what are my options at this point? Because I have quite a bit of them. About 900. Grams


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## Yggdrasil (Oct 2, 2022)

Rreyes097 said:


> So i have those Ic chips that came off of the ram sticks. These chips (forgive me because I don't know the actual nes for these) so I have no real base metals to worry about. I have already washed them I'm hot HCl 3 times, then rinsed with water until my rinses were pretty clear. So which process do I need to do? Pyrolyzation or incineration? I tried to just burn a pan of them with a torch.
> It let off far too much smoke of nasty smell. So what are my options at this point? Because I have quite a bit of them. About 900. Grams


Both.
Pyrolizing to get out the volatiles, then incineration to burn off the carbon.
There are several threads dealing with this, even the hardware to do so.
Just search and read.


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## DJPGold (Oct 2, 2022)

kurtak said:


> First off - if you are processing "a good mix" (all types) of ICs you should most certainly get MUCH more the 4 grams gold from 20 kg chips
> 
> To put it in perspective - if you processed NOTHING BUT 20 kg of PROMS (the very lowest grade of chips) then yes you would only get (about) 4 grams
> 
> ...


Can you please clear up why we need to remove the magnetic materials before washing/rinsing off the carbon after milking?
A process that I’ve used quite a lot in the past is Incineration>milling>sieving>wetting,let settle for 30ish minutes>siphon and repeat>dry cleaned material in a stainless pot>magnetic separation>refining

I’ve always gotten a good yield from this.
Just having trouble wrapping my head around why the magnetics need to be removed before washing


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## orvi (Oct 3, 2022)

Rreyes097 said:


> So i have those Ic chips that came off of the ram sticks. These chips (forgive me because I don't know the actual nes for these) so I have no real base metals to worry about. I have already washed them I'm hot HCl 3 times, then rinsed with water until my rinses were pretty clear. So which process do I need to do? Pyrolyzation or incineration? I tried to just burn a pan of them with a torch.
> It let off far too much smoke of nasty smell. So what are my options at this point? Because I have quite a bit of them. About 900. Grams


That is the thing. Any half-baked open air burning is incomplete. You need to do this in furnance, where you can maintain at least 700-800°C to maintain steady and complete burning. This was discussed so many times... Dig it up here on the forum, kurtak has a lot of experience with this.
In electric furnance you don´t have nice flow of air, so if you put chips inside, you will effectively create smoking bomb 
Thing is, if you have plenty of oxygen, long retention time in furnance and high temperature inside = good insulation of the furnance- you can take practically any organic material and burn it that completely, that no particle of unburnt harmful carbon residue will escape.
Don´t use torch, but heat gun. One that can go up to 600°C or better more. And has temperature regulation, so when burning kicks in, you can lower the temperature to catch the air influx sufficient to burn completely. And avoid melting of the ashes, as carbon can get insanely hot.


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## snoman701 (Oct 3, 2022)

Actually, a proper incineration is to heat to 450 degrees C in a reducing environment effectively pyrolizing all of the volatile ingredients, then 650 degrees C in an oxidizing environment. You do not want to go above the melting temperature of aluminum. 

The smoke from the 450 degree pyrolisis is to be fed into an appropriate afterburner to fully oxidize the volatile agents.


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## kurtak (Oct 3, 2022)

Things I have posted about proper incineration









Separating all metals from carbon and organics


Hi All, Was wondering if someone with a little more knowledge - and who may have tried it - would be able to advise. I have stacks of PCB boards, cell phone boards, IC chips etc etc and each has it's own "best practice" way of extracting the precious metals from it. Many topics like that on...




goldrefiningforum.com













What about beryllium in IC chips


I've yet to see one person on this forum or other forums who can demonstrate a safe way of burning this stuff in practise. i.e. as they are doing it, not just "here's a design for xxx." Yeah sure there's ways it can be done but nobody has demonstrated they are doing it. 4metals had a great pot...




goldrefiningforum.com





And this is a good "general info" thread about pyro (incineration/smelting) processes for e-scrap 

Edit; - Opps - forgot to post the link









Pyrolysis reactor


All, Since I have been manually depopulating boards, and have accumulated lbs of ICs, SMD capacitor and Ta capacitors. I designed the following prototype as a pyrolysis reactor to rid of fumes, then incinerate them following ball mill, and finally smelting. This design is from NoIdea's post as...




goldrefiningforum.com





Kurt


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## Yggdrasil (Oct 3, 2022)

kurtak said:


> Things I have posted about proper incineration
> 
> 
> 
> ...


Excellent, these deserves being read again, a lot of good information in here.


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## kurtak (Oct 3, 2022)

snoman701 said:


> You do not want to go above the melting temperature of aluminum.



Based on my experience - going above the melt temp of aluminum is actually not a concern (during pyrolizing/incineration) 

Why ?

because the aluminum that is in some IC chips is usually the heat spreader that the *underside* of the silicon die sits on (if they are aluminum bond wires it doesn't matter anyway)

the gold bond wires come into & attach to the *top side* of the die

so there is a thin layer of epoxy between the bond wires & the heat spreader

when the epoxy turns to carbon it leave a thin carbon insulation layer between the bond wires & aluminum heat spreader

Because of the huge difference in the melt temp between aluminum & gold - when the aluminum gets molten the carbon at the bottom of the chip will crack allowing the aluminum to ooze out the bottom of the chip leaving the bond wires embedded in the carbon layer between the heat spreader & the bond wires

At least that has been my experience & having run several tests to see if that held true

I can post those test results - if need be --- (& time allows - if you ask)

Kurt


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## kurtak (Oct 3, 2022)

DJPGold said:


> Can you please clear up why we need to remove the magnetic materials before washing/rinsing off the carbon after *milking*?



First of all - per the bold print - I assume you mean milling & not milking  

That said - anytime you are washing material to concentrate the values (in this case gold bonding wires) you want the size of the material to be relatively "uniform" in size

Why ?

Because in the washing process - lager material will cause a turbulence in the wash water & that turbulence will cause smaller material to lift & wash over the top of what is collecting/loading in your concentrator device (whether it be a sluice box, blue bowl, gold pan or fine gold concentration table)

Example; - say you are running a 4 or 6 inch gold dredge - once the riffles in the sluice box becomes loaded with larger rocks - the turbulence caused by those larger rocks is going to start to cause smaller/finer gold to lift & wash over the top of the material loaded in the riffles

That does not mean that you won't also collect smaller/finer gold in the sluice box - because you most certainly will --- it only means that once the riffles are loaded with larger rocks - the turbulence caused by the larger rocks start lifting some of the smaller/finer gold washing some of that gold out the sluice box

Like wise - the Kovar wires & or heat spreaders - which are much larger then the bond wires - will cause this same kind of turbulence in your concentrator device & though you will certainly collect bond wires - some will most certainly lift & washout

So you need to remove those lager Kovar wires/heat spreaders with sifting &/or magnet before running your milled carbon/ash through your concentrator device --- if you don't - though you will collect bond wires - gold will most certainly be lost

Even with relatively uniform material size you can wash gold away if - (1) water flow is not adjusted according to material size &/or (2) the rate at which you feed the material to the device is not done right --- & that is a discussion all it's own

AND - for what it is worth - IMO - a blue bowl is one of the worst devices you can use for concentrating chip ash/carbon - worse than that is using a piece of ribbed drain pipe

Kurt


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## Shark (Oct 3, 2022)

kurtak said:


> AND - for what it is worth - IMO - a blue bowl is one of the worst devices you can use for concentrating chip ash/carbon - worse than that is using a piece of ribbed drain pipe


I agree, been through that disaster before.


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## Liquidau (Oct 4, 2022)

Please elaborate Kurt. Why is the blue bowl so bad? BTW I have not had success with it either, but I’d love to know the pitfalls you have experienced….Thanks.
Len


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## kurtak (Oct 5, 2022)

Liquidau said:


> Please elaborate Kurt. Why is the blue bowl so bad? BTW I have not had success with it either, but I’d love to know the pitfalls you have experienced….Thanks.
> Len


First of all & right out the gate you have to feed a blue bowl extremely slow - you can actually pan with a regular gold pan faster then a blue bowl - by a lot

With a gold pan (depending on the size of the pan & how good you are with a pan you can pan about 1/2 cup to 1 cup of starting material to a concentrate in about 10 or 15 minutes

Thats because with a pan you can shake the pan back & forth &/or tap the side of the pan (hard tapping) with your hand causing the heavies (gold) to move down in the material - leaving you with a gold free layer on top of the material which can then be washed off relatively quick &/or aggressively - it is of course a repeat shake down wash off process but can be done relatively quick

now then - before moving on to the blue bowl - it is important to understand that in fine milled chip ash/carbon that besides the bond wires there are other heavies in the carbon/ash --- fillers used in the epoxy & & fine bits of the silicon die (created during milling) --- in panning those heavies going to the bottom of the pan along with the bond wires (due to the shaking & tapping) making up you concentrates

How a blue bowl works (at least in theory) is with an incoming flow of water - from the outside of bowl - that swirl's around the bowl - moving to the center of the bowl (where the cone is) - BUT - the water flow has to be adjusted (in theory) such that it will leave the heavies deposited across the bottom of the bowl &/or at the bottom of the cone while lifting the lighter material up the side of the cone & out the hole at the top of the cone

As a side note; - this may work well with "fine" placer gold &/or fine milled ore - I don't know because I have only used it for chip ash/carbon - which acts different then placer/ore --- (to be explained)

So - with chip ash/carbon (milled & sifted to 80/100 mesh minus) in a blue bowl this is what happens

First of all - you can not just put a 1/2 cup to 1 cup ash/carbon in the bowl - that because it will "load" the bowl with material (both heavy & light) & at first just the light stuff will go across the bowl & up & out the cone - but then a layer of heavies will develop on top of the material preventing the flow from washing the light material under that layer of heavies basically stopping the washing process --- if you turn the flow up to move the top layer so the flow can get to lighter material under it - then the flow is strong enough to push those heavies up & out the cone --- & there goes your gold

So - first you have to have a flow set that will move the light material without moving the heavy material AND you have to feed that material very slowly - like a teaspoon or less at a time so the flow has time to wash the light material way --- which is all fine & dandy at first BUT as more material is added (slowly) the heavier material slowly moves across the bowl to the cone & a few thing start happening 

the build up of the heavies start creating a resistance to the lighter stuff moving across the bowl & that resistance starts causing the heavies to push across to the cone along with the lighter stuff - which will cause the small surface area round the cone to become "loaded"

Once loading at the cone happens it will start to cause heavies to go across to top of the "loaded" material & up & out the cone along with the light stuff --- you can sit there & watch bond wires go up & out the top of the cone once you get loading at the bottom of the cone 

Loading will start happening after about 1/2 cup to 2/3 cup material & because of slow feed speed that will take an hour or more - at which time you have to shut it down to clean the bowl & start again

To clarify --- to much water flow & heavies go out the bowl right out the gate with the light stuff --- to little flow the bowl loads with both heavy & light causing above problems - get the flow just right & it is still just a matter of time to loading & clean out

Now then why are bond wires (chip ash/carbon) different the placer/ore ?

Because when milling chips - the wires tend to twist & bend - being twisted & bent allows water to get under them & lift them allowing them to roll & tumble across a slick surface (like a blue bowl) &/or the surface of built up heavies (which is why wires start going with the light stuff once the bowl is loaded)

With a pan the wires shake/tap down giving you a gold free layer/zone to wash off

on a concentrator table you have ribs in the mat the wires come up against to stop the roll/tumble of the wires

even with a table - once it is loaded - you have to stop for clean out - or gold (wires) will roll/tumble across the top & out the end - BUT - you can build (or buy) a table with a *much* larger surface area then a blue bowl & therefore feed *much* fast & run *much* more material before clean out

IMO - the blue bowl I bought when I first started was one of the worst investments I ever made --- it only took about 3 - 4 days of *trying* to use the blue bowl to figure out that I could pan more material faster by going back to my good old gold pan - & building a table was a big step up from that

IMO - & based on my personal experience when it comes to concentrating chip ash/carbon - listed from worst to best the list is as follows

ribbed drain pipe (cut in half) don't even think about it 

blue bowl - just not worth it

gold pan - good for 5 - 10 pound batches

concentrator table with good surface area (not shaker) - really want/need it for over 10 pound batches

actual shaker table - the best

Kurt


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## sayf (Oct 5, 2022)

kurtak said:


> First of all & right out the gate you have to feed a blue bowl extremely slow - you can actually pan with a regular gold pan faster then a blue bowl - by a lot
> 
> With a gold pan (depending on the size of the pan & how good you are with a pan you can pan about 1/2 cup to 1 cup of starting material to a concentrate in about 10 or 15 minutes
> 
> ...


thank you very much kurt, i carefully used your instructions step by a step and this time i got 14 grams of gold out of 10 kilo grams of IC chips , i incinerated the ic chips in a furnace and powdered them using a small ball mill then i sieved powder and collected the ash , i run a weak magnet on the ash to get rid of the kovar and gave the powder a wash in nitric acid before washing it with water , every thing went great and 1.4 grams of gold per kilogram of ic chips is an expected outcome .
can you give us some information about your concentrator table i think am gonna make one as it looks very great for big patches ?


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## snoman701 (Oct 5, 2022)

sayf said:


> i run a weak magnet on the ash to get rid of the kovar and gave the powder a wash in nitric acid before washing it with water , every thing went great and 1.4 grams of gold per kilogram of ic chips is an expected outcome .


You are processing the kovar legs as well right?


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## sayf (Oct 5, 2022)

snoman701 said:


> You are processing the kovar legs as well right?


i processed the silicon dies with the concentrate in the final aqua regia step , and ill of course process the kovar legs when i get a big quantity.


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## snoman701 (Oct 5, 2022)

Just put the kovar legs in your waste acid.


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## Liquidau (Oct 5, 2022)

Thanks Kurt. Terrific explanation as usual. Back in the box it goes.
Do you have an opinion/experience on the Gold Cube? Supposed to manage a quite large volume of material, that’s not necessarily classified to 80 mesh (although that should help)?


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## sayf (Oct 7, 2022)

snoman701 said:


> Just put the kovar legs in your waste acid.


Great idea


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## FriscoDad (Oct 12, 2022)

kurtak said:


> ribbed drain pipe (cut in half) don't even think about it
> 
> blue bowl - just not worth it


Hi @kurtak
Thank you for your detailed explanation of the deficiencies of the blue bowl when recovering gold from IC chips.
Can you provide some background as to why you dismiss the ribbed drain pipe? Is it similar to the limitations of the blue bowl, too slow and labor intensive? I saw a youtube where a guy created an automatic system to feed the concentrate into the water flow so he didn't have to sit there and feed it in manually teaspoon by teaspoon.
Or are there other reasons?

Edited for a typo.


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## kurtak (Oct 12, 2022)

FriscoDad said:


> Can you provide some background as to why you dismiss the ribbed drain pipe?


Because a pipe (whether ribbed or not) has a very narrow surface area (1/2 to 1 inch wide) once that narrow surface area becomes "loaded" EVERYTHING (including bond wires) just starts washing over the top & past the sides - that loading - on a very narrow surface area happens very quickly

There is a reason sluice boxes & concentrator tables are made with a wide *flat* surface & NOT a round surface

Kurt


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## Rreyes097 (Dec 24, 2022)

kurtak said:


> First off - if you are processing "a good mix" (all types) of ICs you should most certainly get MUCH more the 4 grams gold from 20 kg chips
> 
> To put it in perspective - if you processed NOTHING BUT 20 kg of PROMS (the very lowest grade of chips) then yes you would only get (about) 4 grams
> 
> ...


Kurt I could really use your help. Going back and forth on these threads are not helping me understand all of the information. I just incinerated a few BGA chips and a lot of RAM DDR 2 chips. Also there were a few chips that did contain legs. I didn't process a lot because I'm still trying to figure out the whole process and do it correctly thus far I have incinerated them and then used a coffee grinder to grind them down. Then I sifted them through a basic sifter kitchen sifter? Now I'm not sure what I'm doing for next. I'm sitting over the fine sifted Ash and stuff pulling out visible wires but some of them look to have gold on them aren't they supposed to stay in? The only other time I did Ic chips was a bunch of the same ddr2 no legs on the chips style. The problem then was my incineration, it wasn't good enough but when I did incinerate them enough I was able to pull out all the gold and things are great but this has some of that the same chips along with a couple mixed ones with legs in it. I started to run a weak magnet over it but was afraid that I was pulling up gold bonding wires that were attached in the mix so I stopped that and I just started pulling out visible wires. But like I said these wires don't look to be just copper some of them look to have gold on them or maybe it's the trick of the light I don't know I've read a bunch of threads on how to do this and I thought I didn't know how to do it but I don't know what's wrong I think I'm just confused if you can offer any help one-on-one that would be great if not I understand thank you very much.


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