IC chips gold recovery

[orvi]

Recovery of Precious metals :

1. Mechanical Separation of all metallics from non metallics
2 Separation of metallics (Iron /Al and Cu plus Precious Metals)
3. Melting of Cu+PM - Anodes
4. Cu refining and collecting PM Anode slime
5. Recovery PM by Hydrometallurgy

Most Economical, Portable, Feasible and high accountability

You skipped that part where you prepare the copper to be electrorefined. In other words, eg pins are never pure copper. So aren´t the PCB´s, which contain awful lot of tin and lead. If you melt this into anode bars and start to electrorefine... it won´t be nice.

 

[J.Najam]

My bad I see it’s coal now, cut a hole in the bottom of that container get 3-4” inch duct and a blower fan and install to induce a better draft. Then you can melt iron with that “

Ah yes, it was a coal burner. I used the small oak-meal tin/steel can for this purpose. The burner was fine, I put my graphite crucible for a temperature check and the colour turned bright orange within 15 minutes. But I really don't know why it didn't work out for the process I intended to carry

 

[J.Najam]

It looks cold to me. For natural air circulation, not forced oxygen. Not even red hot.

I didn't use the forced oxygen technique here as I feared it may enforce the sediment out of the vessel. Prior to my procedure, I gently blew some air into it to check if it would've been ok. But after my observation, I used the open air for circulation, at first I used a larger pan, an hour later no result, it was all the same. Then I used this bowl that can be seen for another hour and a half. How long is it supposed to be given?

 

[orvi]

I didn't use the forced oxygen technique here as I feared it may enforce the sediment out of the vessel. Prior to my procedure, I gently blew some air into it to check if it would've been ok. But after my observation, I used the open air for circulation, at first I used a larger pan, an hour later no result, it was all the same. Then I used this bowl that can be seen for another hour and a half. How long is it supposed to be given?

It need to be at least red hot. Visibly at least red glowing from the top of the layer. To burn carbon at sane rate with just air. Frequently stirring with some piece of metal or graphite rod. Best is to do it in the evening or when there is not that much light, as changes in color are very nicely visible. Then you can blow air through some metal tubing onto the material (gently) and watch that response - if it retain the colour, go brighter or go darker. If it go darker (air does not combust anything, just cool off the surface), this layer is done. If it retain similar colour or start to glow brighter, it need more cooking.
--------------------------------------------------
That is why oxygen line is handy. As it is much quicker, easier and also informative. Oxygen concentrator is nearly a must-have for small scale refiner for reactions, oxidations, efficient burning but most importantly for sustained small oxy/propane burner for easy and quick melting. No more carrying the oxygen pressure tanks
5L/min 90+% O2 is the minimum to be purchased for small oxy/propane melting. Buy used stuff, look for hours of runtime and negotiate the price depending on the hour number Now is the good time to buy these machines, as people are getting rid of them after COVID era. New DeVilbiss machines cost around 1000 euros here, but 1500h runtime ones (even still in 2 or 3 year warranty) go easily below 500 euros. Anything with less than 2500h and below 400 is very reasonably priced. You can easily hook up two of them parallel to get 10L/min of oxygen, which is enough for more serious torch melting. Or even buy one dedicated for two patients, that can alone deliver 10L/min.

 

[venkym]

Hydrometallurgy isn´t the only way to do this, and yes, it is the worst option here. One of the fastest ways to process IC´s is thorough incineration, where you benefit from combustion heat to sustain the burning in nicely isolated furnance, only then aid with some heatgun hot air to continue incinerating till carbon free. Separate the magnetic legs and powder. Smelt the powder with some collector of your choice, lead/bismuth molten dip the magnetics.
Your final product will be enriched metallic bead from ashes and lead/bismuth blob, which can be easily cupelled. Eventually you combine these two together and cupell at once. Some people just pyrolyze the chips, then sluice the powder and treat legs with AP. There is many possibilities how to do this.

But with incineration/smelt/molten Pb/Bi dip - no AP leaching, no gallons of greenish-black acidic junk you need to treat and dispose. Molten lead/bismuth dip isn´t 100% efficient, but you can always bath the legs the second time and save this Pb/Bi wash for next batch. All in all, hydro in this case also isn´t 100 % efficient

i agree technically but commercial scale and economic viability will be at risk!

 

[Yggdrasil]

i agree technically but commercial scale and economic viability will be at risk!

Welcome!
I see you managed to sneak by the welcome committee
Anyway if you are going to stay or even worse mess with chemistry
We want you to study these topics:

1. Read C.M. Hokes book on refining jewelers scrap, it gives an easy introduction to the most important chemistry regarding refining.
It is free here on the forum: Screen Readable Copy of Hoke's Book
2. Then read the safety section of the forum: Safety
3. And then read about "Dealing with waste" in the forum: Dealing with Waste

Suggested reading: The Library

Forum rules : https://goldrefiningforum.com/threads/gold-refining-forum-rules.31182/post-327766

 

[orvi]

i agree technically but commercial scale and economic viability will be at risk!

That is what I try to imply the most. The simplest (not always the best) way how to catch on production scale is to know what big guys are doing. In the meantime, it is probably the most efficient and economical way of doing things
And yes, every bigger player process whole boards and e-scrap by means of pyrometallurgy and electrochemistry. Hydrometallurgy still has it´s place in separating complicated ore concentrates and mainly precious metals recovery, but it is not as big as we may mistakenly see through our narrow lens of PM refining here

PS: There can´t be economic viability if the process does not work. Waste treatment is expensive. Workforce is expensive. Heating stuff and melting stuff is still relatively cheap in bulk. So is the disposal of relatively harmless slag materials, opposed to leachates with heavy metals.
That mean, what you can possibly do by pyrometallurgy, you do by pyrometallurgy.

 

[J.Najam]

It need to be at least red hot. Visibly at least red glowing from the top of the layer. To burn carbon at sane rate with just air. Frequently stirring with some piece of metal or graphite rod. Best is to do it in the evening or when there is not that much light, as changes in color are very nicely visible. Then you can blow air through some metal tubing onto the material (gently) and watch that response - if it retain the colour, go brighter or go darker. If it go darker (air does not combust anything, just cool off the surface), this layer is done. If it retain similar colour or start to glow brighter, it need more cooking.
--------------------------------------------------
That is why oxygen line is handy. As it is much quicker, easier and also informative. Oxygen concentrator is nearly a must-have for small scale refiner for reactions, oxidations, efficient burning but most importantly for sustained small oxy/propane burner for easy and quick melting. No more carrying the oxygen pressure tanks
5L/min 90+% O2 is the minimum to be purchased for small oxy/propane melting. Buy used stuff, look for hours of runtime and negotiate the price depending on the hour number Now is the good time to buy these machines, as people are getting rid of them after COVID era. New DeVilbiss machines cost around 1000 euros here, but 1500h runtime ones (even still in 2 or 3 year warranty) go easily below 500 euros. Anything with less than 2500h and below 400 is very reasonably priced. You can easily hook up two of them parallel to get 10L/min of oxygen, which is enough for more serious torch melting. Or even buy one dedicated for two patients, that can alone deliver 10L/min.
View attachment 56982

Thankyou for this wonderful piece of information @orvi , really appreciate it.

It may not be feasible for me to buy at this point in time. Maybe in the future InshaALLAH. One thing I wanted to know, it may sound like a baby question given the requirement, but will a bubbler work through the same concept as this? Like we use the same as an oxygen source to assist the HCl in the CuCl2 etching process, so would it be feasible to perform? It may not have the same strength and may take much longer compared to the one you have shared, but it could act as a source of oxygen to at least initiate and get things going.

 

[J.Najam]

Recovery of Precious metals :

1. Mechanical Separation of all metallics from non metallics
2 Separation of metallics (Iron /Al and Cu plus Precious Metals)
3. Melting of Cu+PM - Anodes
4. Cu refining and collecting PM Anode slime
5. Recovery PM by Hydrometallurgy

Most Economical, Portable, Feasible and high accountability

Thanks for your information but I'm trying to start with the very basics. I may look into it later and we still have to perform some chemistry in the end. So for the time being I'll stick to the processes I'm learning right now. Thanks

 

[Yggdrasil]

Thankyou for this wonderful piece of information @orvi , really appreciate it.

It may not be feasible for me to buy at this point in time. Maybe in the future InshaALLAH. One thing I wanted to know, it may sound like a baby question given the requirement, but will a bubbler work through the same concept as this? Like we use the same as an oxygen source to assist the HCl in the CuCl2 etching process, so would it be feasible to perform? It may not have the same strength and may take much longer compared to the one you have shared, but it could act as a source of oxygen to at least initiate and get things going.

I'm a bit confused now.
Are you talking about using the air pump while incinerating, then it is not bubbling.
In that case, any small extra circulation of air will be good as long as it don't blow any dust away.
A small fan or similar will be even easier.

 

[J.Najam]

Are you talking about using the air pump while incinerating

Yes an air pump, but not the same as Orvi mentioned in his posts above. With a bubbler I was going with the concept of an air throw, so I thought maybe it could be used for the same, ofcourse bearing other factors such as using a non combustible pipe for air blowing into the incineration dish

A small fan or similar will be even easier.

This seems like do-able at the moment. Will try working my way around this.

Thanks

 

[Martijn]

Recovery of Precious metals :

1. Mechanical Separation of all metallics from non metallics
2 Separation of metallics (Iron /Al and Cu plus Precious Metals)
3. Melting of Cu+PM - Anodes
4. Cu refining and collecting PM Anode slime
5. Recovery PM by Hydrometallurgy

Most Economical, Portable, Feasible and high accountability

For which types of material are these detailled steps applicable? Ceramic cpu's? Whole pcb's? How is the proccess highly accountable? How do you deal with waste?

I find this a bit too simple explanation of recovery of precious metals. There may a much better way for most material.

 

[orvi]

For which types of material are these detailled steps applicable? Ceramic cpu's? Whole pcb's? How is the proccess highly accountable? How do you deal with waste?

I find this a bit too simple explanation of recovery of precious metals. There may a much better way for most material.

All in all, these steps are in fact the ones used industrially. But it isn´t one sentence, but whole book chapter each and some key points are excluded here, like treatment of the mixed metal melt to eliminate problematic elements like lead and tin before electrorefining can even be planned. This pyrometallurgical (or hydrometallurgical) cleaning stage is probably the most difficult step, and because of proprietary methods, not very much is known publically. There are some general reactive pyrometallurgy techniques, but all in all it is very similar to PGM refining

 

[Ayham Hafez]

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)

https://goldrefiningforum.com/threa...ic-types-of-ic-chips-flatpacks-and-bga.22951/
That said ------


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

Some big companies using pyrometallurgy process don't incinerate ic chips or any other PCBs components, they just shredding then crushing to very small particles, then concentrating using shaking table then smelting and make copper anodes then use copper electrolysis system to collect PGM's, is this process ok for ic chips or incineration is a must?

 

[AustAuScrap]

Hi, I am not sure if this Question is in the right section, and if not please feel free to move if needed. The Basic question is would a Ozone generator and then bubbling the ozone through the HCL in a bath to dissolve base metals be viable and or any quicker than bubbling "Air".
secondly- also from left field,
after the shred and pulverizing process (From above regards commercial processing) -is any one using a liquefaction and centrifuge type process to separate the anode materials (metals) instead of shaker table concentrating?
Just asking because I have a ozone generator - water treatment purification type and also a centrifuge from a Lube oil regen/cleaning plant among my collection of assorted "junque"
Thanks in Advance

 

[Yggdrasil]

Hi, I am not sure if this Question is in the right section, and if not please feel free to move if needed. The Basic question is would a Ozone generator and then bubbling the ozone through the HCL in a bath to dissolve base metals be viable and or any quicker than bubbling "Air".
secondly- also from left field,
after the shred and pulverizing process (From above regards commercial processing) -is any one using a liquefaction and centrifuge type process to separate the anode materials (metals) instead of shaker table concentrating?
Just asking because I have a ozone generator - water treatment purification type and also a centrifuge from a Lube oil regen/cleaning plant among my collection of assorted "junque"
Thanks in Advance

Ozone in HCl might dissolve the Gold, as Ozone is a much more powerful Oxidizer than plain air.
I do not understand your second part, please elaborate.

 

[AustAuScrap]

Reference to "Some big companies using pyrometallurgy process don't incinerate ic chips or any other PCBs components, they just shredding then crushing to very small particles, then concentrating using shaking table" is what I was referring to, -
specifically adding water (or other liquid)to the pulverized product and then using a centrifuge to separate out content of different weights.
Supposedly by controlling RPM it is possible to separate what will rise up the cones of the centrifuge to a outlet, while other other other out of spec goes to drain.

MY first language was not English either so language errors may occur as I tend to use note form rather than grammatically correct, or "Oxford" or "American" speaking levels of language.. Apologies

 

[Yggdrasil]

Reference to "Some big companies using pyrometallurgy process don't incinerate ic chips or any other PCBs components, they just shredding then crushing to very small particles, then concentrating using shaking table" is what I was referring to, -
specifically adding water (or other liquid)to the pulverized product and then using a centrifuge to separate out content of different weights.
Supposedly by controlling RPM it is possible to separate what will rise up the cones of the centrifuge to a outlet, while other other other out of spec goes to drain.

MY first language was not English either so language errors may occur as I tend to use note form rather than grammatically correct, or "Oxford" or "American" speaking levels of language.. Apologies

Ok, I was confused by the use of the term "Anode material" in stead of metal concentrate or similar.
It was too similar to "Anode Slimes", so I just wanted that cleared up.

Shredded materials are usually smelted, and no acids are used, hence no need for bubbling anything.

Bubbling air is used in the Cupric Chloride leach (AP) for dissolving Copper behind Gold plated pins or "fingers" and such release the plating from the substrate.

 

[AustAuScrap]

Thank you for your answer re the Ozone, so on to the next question, would increasing the volume of air put into the bath also risk dissolving gold ?
or
Could the physical agitation effect of extra air be useful in the process so that a greater area is available for the chemical reaction to happen.
Thanks For your next reply Too,
Dealing with Electro-refining slime's is a lot further down the process than these stages I am talking about. At this stage I am dabbling with the design of process for collecting the basic metals from leaching, and then Electro winning/refining the copper out before proceeding to the slime's treatment progressively through to the gold.
In fact looking at it deeper, because I would end up processing slime's eventually extra gold dissolved because of the ozone (if it was substantial) would not matter, as long as it was not lost during my other process steps.

I am trying to achieve a happy mix of using what I have available Free as my method.
And now a extra question if I can, a Safety related one, do you know of any one having problem with getting polonium as a by product when using Ewaste as the feed stock?
When I was employed every now and again because of the original ore. polonium levels could rise high enough that refined copper had to be rested until level fell to accepted standards. Does this ever occur when Ewaste is processed ?

Takk skal du ha ( I think it means thank You)​

 

[Yggdrasil]

Thank you for your answer re the Ozone, so on to the next question, would increasing the volume of air put into the bath also risk dissolving gold ?
or
Could the physical agitation effect of extra air be useful in the process so that a greater area is available for the chemical reaction to happen.
Thanks For your next reply Too,
Dealing with Electro-refining slime's is a lot further down the process than these stages I am talking about. At this stage I am dabbling with the design of process for collecting the basic metals from leaching, and then Electro winning/refining the copper out before proceeding to the slime's treatment progressively through to the gold.
In fact looking at it deeper, because I would end up processing slime's eventually extra gold dissolved because of the ozone (if it was substantial) would not matter, as long as it was not lost during my other process steps.

I am trying to achieve a happy mix of using what I have available Free as my method.
And now a extra question if I can, a Safety related one, do you know of any one having problem with getting polonium as a by product when using Ewaste as the feed stock?
When I was employed every now and again because of the original ore. polonium levels could rise high enough that refined copper had to be rested until level fell to accepted standards. Does this ever occur when Ewaste is processed ?

Takk skal du ha ( I think it means thank You)​

Correct