Non-Chemical Scaling up IC chip processing

[orvi]

I've considered using tin metal as a collector and then electro-refine the tin in an electrolytic cell. HCl would be the electrolyte.

Tin is very stubborn metal for electrolysis. Growing crystals are very much resembling whiskers, as kurtak said. With that i dont say that it couldn´t be done. Mechanical scraper would be the best option here, or rotating electrode that wil crush the growing crystals against the wall of the cell continually.



Once, i did electrolysis of molten tin in molten SnCl2 electrolyte. Funky stuff, certainly nothing healthy (SnCl2 vaporizing in white smoke clouds) and probably just as interesting thing without of value for this refining need. But there, whiskers will not be an issue
It would be easier to melt it, but reclamation of gold from tin could be a nightmare. Maybe the thing will be dissolving it in hydrochloric acid directly, but also not the optimal setup, tin oxides formation from hydrolysis etc...

Another option with tin will be to switch into organic solvent. Classical preparation in inorganic chemistry class: making SnI4 from tin and iodine, in the chloroform as solvent.
There will be numerous issues with gold reclamation tho. Firstly, gold will dissolve too iodine could be substitued with cheap chlorine, but i dont think this approach will be of any benefit. Chlorine with organics often result in runaway chlorinations (extremely exothermic), that is why chloroform is used as solvent (nasty stuff also).

Bismuth is in other hand relatively easy to melt (271 °C), readily cupell out, leaving the gold button. Also, after a while with more used cupells, they could be easily crushed and smelted with carbon to reclaim bismuth back. Purity of reclaimed metal will be questionable tho, as other base metals (tin, lead, copper...) involved will reduce too.

 

[Geo]

The problems (there are two) with running tin in a parting cell (like a silver or copper cell) is tin whiskers

the reason they are called whiskers is that they grow VERY long & VERY fast like whiskers on a cat

because of the short distance between anode & cathode (about 4 inches) the whiskers will grow very quickly between anode & cathode & short the cell out --- so you have to knock the whiskers down VERY OFTEN

I watched a video (like 6 or 7 years ago) where some students played with the idea (tin cell) --- in order to overcome the FAST whisker growth problem they set up a roller that would automatically roll over the cathode to knock down the whiskers - the roller would have to knock the whiskers down about every 10 minutes

In other words - unless you have something set up to knock the whiskers down automatically & often - unlike a silver or copper cell - you can't just turn on the power supply & walk away - you have to stay on top of the cell to knock the whiskers down OFTEN

The other problem is the anode slimes --- as you know - with a copper or silver cell the "other" PMs (gold &/or PGMs) end up in the slimes which then need to be treated to recover those "other" PMs

in a copper or silver cell those slimes will be MOSTLY copper or silver (plus/minus 80%) so you still need to part the copper/silver from the "other" PMs --- that in it's self is not an easy task --- there is a reason Nick "often" refers to them as swine's (instead of slims) they are a pig to deal with

You would/will have the same problem with a tin cell - tin slimes to part your gold/PGMs from

Slime can be a real pain in the butt especially if other metals are involved (like lead, iron etc. etc. etc.)

If/when "other" metals are involved it can/will take "multiple" treatments to part the PMs from the slimes

Generally speaking - anodes from a smelt have other metals involved - other then the "target" metals (silver/gold - copper/gold or in this case tin/gold) which is why processing slimes are OFTEN a pain in the butt (or swine's)

There is the old saying --- tin is a refiners nightmare - IMO - cleaning up the slimes from a tin cell would be nothing short of a nightmare

If your dore metal (from the smelt) was ONLY tin & gold - then why not just dissolve the tin away with HCl & let the gold settle --- if other metals are involved the tin is going to be a problem whether you run it in a cell or run it through otherwise normal processes

Not saying a tin cell wouldn't work --- just that you will have the same problem with the slimes as you would have processing dore metal (with tin from a smelt) by other normal processes --- parting PMs from other metals including tin

It might be a fun experiment but a don't think there would be any advantage over already proven methods - more likely additional problems

IMO

Kurt

A salt bridge would effectively stop the problem of short circuit in the cell. I built a small copper parting cell and was using nitric acid as the electrolyte and had to use a salt bridge because there was some material that tended to float and stay suspended.

 

[speed]

The lead/bismouth method will absorb copper too wont it? Will it absorb all of the gold and then some copper until it becomes saturated or is there a danger it wont absorb all of the gold if too much copper is present?

I also understand it will produce a copper/gold alloy after the cupulation unless there is a large excess of lead as the copper doesnt readily oxidize and get pulled away into the cupel? I have been warned off using cupelation to refine copper containing scrap before for this reason. Do you think it would make an alloy pure enough to simply treat like karat gold and move to wet refining?

I think from my point of view im looking for a process that doesn't involve as many steps as traditional IC recovery does. Its the labour that makes it uneconomical. If it was possible to pyrolise and crush then grade out all the larger pins and legs before moving straight on to smelting with Lead/Bismuth i can see some potential to cut out a lot of work..

 

[Geo]

The lead/bismouth method will absorb copper too wont it? Will it absorb all of the gold and then some copper until it becomes saturated or is there a danger it wont absorb all of the gold if too much copper is present?

I also understand it will produce a copper/gold alloy after the cupulation unless there is a large excess of lead as the copper doesnt readily oxidize and get pulled away into the cupel? I have been warned off using cupelation to refine copper containing scrap before for this reason. Do you think it would make an alloy pure enough to simply treat like karat gold and move to wet refining?

I think from my point of view im looking for a process that doesn't involve as many steps as traditional IC recovery does. Its the labour that makes it uneconomical. If it was possible to pyrolise and crush then grade out all the larger pins and legs before moving straight on to smelting with Lead/Bismuth i can see some potential to cut out a lot of work..

When I am processing chips in amounts of 100 pounds or more, I incinerate, mill and use a strong magnet to pull the iron parts. I pass the material through 100# screen. This removes most or the copper. Leads are normally larger than 100#. This whole process takes about an hour. Then sluice the solids and run it through the gold wheel. This concentrates the remaining metals nicely. The remaining metals will be copper, silver and gold and small amount of palladium. A nitric acid leach will remove copper, silver and palladium. Now you are left with just gold, some carbon and silica. AR will dissolve the gold.

 

[Liquidau]

Great summary, thanks Geo. Are you concerned that any gold remains behind with the iron? Do you do anything with the remaining sluice stuff?

 

[speed]

Yeh thats basically the method i use already. Too many steps and too much labour time tho.

After some thought I'm fairly sure I'm going to build a bigger furnace and move to smelting. (and copper cell)

That way theres no washing or sifting nessicary. It's just a case of incineration - ball mill - pull out magnetics- smelt with air sparge - copper cell the resulting pour.

I already have copper cell going for other copper based ewaste.

Theres going to be more cost in gas and flux but you can just sit back and let it do its thing so lots of labour time saved.

Lead/bismouth doesnt seem sensible unless your working with predominantly 'non copper'

 

[Geo]

Great summary, thanks Geo. Are you concerned that any gold remains behind with the iron? Do you do anything with the remaining sluice stuff?

There will always be "some" left behind in every process. You do what you can to minimize the amount left behind. Eventually, it will be so little that you will collect it from the waste stream. Even solid gold objects leaves a little behind every time it's touched or moved. I learned from old prospectors a long time ago that amount is called the angels part. If you go chasing after the angels part, you will lose more than you gain.
I ran some chips for lazersteve some years back. The return was less than what was anticipated. I went through the process that I used with him with pictures. He asked for a sample of the ash to see if I was leaching all of the gold. I sent him a nice sample from the bottom. The assay reported a small amount of silver but not enough to chase after. The chips were factory rejects and was only a couple different types of chips for the couple hundred pounds that he sent. The only thing I could figure was that some of the chips had gold bond wires and some of them didn't. Random chips from all the different sources will not have that problem.

 

[Geo]

The iron and magnetic parts are placed in a plastic tray open to the air and moisture. In a years time it's mostly a pile of rust. It dissolves almost instantly in dilute HCl. Of coarse any gold left will be untouched. Or you could dissolve it with any number of acids or combinations of acids to dissolve it faster. Just don't use something that will dissolve gold.

 

[kurtak]

After some thought I'm fairly sure I'm going to build a bigger furnace and move to smelting. (and copper cell)

That way theres no washing or sifting nessicary. It's just a case of incineration - ball mill - pull out magnetics- smelt with air sparge - copper cell the resulting pour.

As the saying goes - there is more then one way to skin cat --- & that is certainly one way

However - I do not believe it is going to be anywhere near as simple as you think

LOTS of problems if you don't FULLY understand it (all of which can be overcome) --- BUT !!!

Don't have time right now to explain but will do my best to explain when I get time --- may not be until this weekend though

Kurt

 

[Liquidau]

The iron and magnetic parts are placed in a plastic tray open to the air and moisture. In a years time it's mostly a pile of rust. It dissolves almost instantly in dilute HCl. Of coarse any gold left will be untouched. Or you could dissolve it with any number of acids or combinations of acids to dissolve it faster. Just don't use something that will dissolve gold.

Great stuff, merci!

 

[Ayham Hafez]

I have one question regard the IC Chips gold recovery process discussed in this thread.

Regardless recovering silver and palladium since most ic chips have very little amount of them، why to make magnetic separation while we can use direct AR and dissolve gold wires plus gold plated on magnetic materials and get optimum recovering results? I mean what's the point of processing the magnetic materials separately?

 

[Yggdrasil]

I have one question regard the IC Chips gold recovery process discussed in this thread.

Regardless recovering silver and palladium since most ic chips have very little amount of them، why to make magnetic separation while we can use direct AR and dissolve gold wires plus gold plated on magnetic materials and get optimum recovering results? I mean what's the point of processing the magnetic materials separately?

The shear volume of magnetic material increases the cost for Chemicals and waste processing.
I know one of the members said he dumped the magnetics in a container outside
with some water and salt and let it sit until the rust had eaten all the Iron.
There might be some minute Gold adhering to the end of some of these parts,
but not enough to be cost effective to process it.

 

[Ayham Hafez]

The shear volume of magnetic material increases the cost for Chemicals and waste processing.
I know one of the members said he dumped the magnetics in a container outside
with some water and salt and let it sit until the rust had eaten all the Iron.
There might be some minute Gold adhering to the end of some of these parts,
but not enough to be cost effective to process it.

While panning ic chips ash will make lose in gold, so we will process a bunch of mud,so how we can know how much AR we should use? If we can know exactly how much AR we need then maybe magnetic separation will make sense.

Yesterday I processed 8 kg of mixed ic chips,I divided them into two equal parts after milling and incineration for second time, first part I did magnetic separation for it, I got 1.4 gram of gold, and when I processed the magnetic materials I got no gold precipitation at all I think because it was very little amount of gold plated on the magnetic materials.

Second part I processed without magnetic separation,I got almost 1.8 grams of pure gold, I think shortcutting process some times save time and increase value!

BTW, I used same amount of AR for both, I think HCL dissolve the magnetic materials without consuming nitric acid because I used same amount of bad urea to denox nitric for both samples, but when I processed the magnetic materials from first sample separately I used more chemicals.

 

[Tanjiro]

Efficiently ramping up IC chip processing is pivotal for meeting growing demands. This requires strategic integration of advanced fabrication techniques, streamlined workflows, and optimized equipment utilization. With meticulous planning and innovation, we can scale up production while maintaining high-quality standards and cost-effectiveness.

 

[Martijn]

Efficiently ramping up IC chip processing is pivotal for meeting growing demands. This requires strategic integration of advanced fabrication techniques, streamlined workflows, and optimized equipment utilization. With meticulous planning and innovation, we can scale up production while maintaining high-quality standards and cost-effectiveness.

Inspected the link but have not read it:
You are not talking recovery, but production correct? Are you a bot?

 

[Martijn]

While panning ic chips ash will make lose in gold, so we will process a bunch of mud,so how we can know how much AR we should use? If we can know exactly how much AR we need then maybe magnetic separation will make sense.

Yesterday I processed 8 kg of mixed ic chips,I divided them into two equal parts after milling and incineration for second time, first part I did magnetic separation for it, I got 1.4 gram of gold, and when I processed the magnetic materials I got no gold precipitation at all I think because it was very little amount of gold plated on the magnetic materials.

Second part I processed without magnetic separation,I got almost 1.8 grams of pure gold, I think shortcutting process some times save time and increase value!

BTW, I used same amount of AR for both, I think HCL dissolve the magnetic materials without consuming nitric acid because I used same amount of bad urea to denox nitric for both samples, but when I processed the magnetic materials from first sample separately I used more chemicals.

I think there may be other factors at play here, were the IC batches identical or mixed?

 

[Tanjiro]

Scaling up IC chip processing involves optimizing manufacturing processes, enhancing equipment capabilities, and refining design techniques spamming link removed to accommodate higher chip densities and complexities. Advancements in lithography, material science, and semiconductor architecture are pivotal. Additionally, improving yield rates and minimizing defects through precise control measures are essential for meeting the demands of increasingly powerful electronic devices.

 

[Yggdrasil]

Scaling up IC chip processing involves optimizing manufacturing processes, enhancing equipment capabilities, and refining design techniques spamming link removed to accommodate higher chip densities and complexities. Advancements in lithography, material science, and semiconductor architecture are pivotal. Additionally, improving yield rates and minimizing defects through precise control measures are essential for meeting the demands of increasingly powerful electronic devices.

Careful now or your stay will be short.
No spamming or links there to is allowed.
Your posts do not make much sense either.

 

[Darkthirty]

Inspected the link but have not read it:
You are not talking recovery, but production correct? Are you a bot?

My first thought was AI

 

[Yggdrasil]

My first thought was AI

The link in the second post was most likely spamming, so I removed the link.