Interesting article on e-scrap from todays New York Times

[4metals]

I'd say that the rotating drum is on the inside, and that's the cover. Even when using low temperature to remove components, you are still heating the board up to a temperature that is going to offgas all kinds of fun fumes, so they have to send all of those fumes to a scrubber.

So those fancy colored sections are the equivalent of a dump enclosure on a ball mill, only to contain fumes. The wired panels are probably heat elements and there is a duct overhead and although we cannot see it, it is probably connected to the outer drums. It would be an interesting plant to tour for sure.

 

[anarxi]

before the war, we made (in Kharkov) and sold such installations.
tank
essentially like a washing machine, only turned on its side.
large cube made of thick steel,
inside a drum with holes on the sides and at the bottom.
loading from the top.
boards with parts were loaded into the drum separator.
then the cube was closed.
a special liquid, already heated, was fed into it through pipes; the composition of this liquid is the main secret of the entire installation.
then the heaters in the cube itself were turned on, the temperature rose to 230 degrees.
thanks to the tightness and the ability to withstand pressure of several atmospheres, the liquid does not boil.
then, after about 15 minutes, the rotation of the separator drum is turned on.
centrifugal force pushes the solder out of the separator and it passes through the mesh and flows to the bottom of the cube, the mesh holds the parts and the boards themselves in the separator.
then the separator is stopped, the liquid is pumped out.
all the solder is at the bottom, the parts and boards are in the mesh.
loading about 60 kilograms.
cost about $2500.
power consumption about 7 kilowatts.

it is very convenient for old soviet boards, which always have a lot of solder.
up to 10% of the board weight without parts

 

[4metals]

It is so disheartening to read a post that starts with "before the war", I can see from Google maps that Kharkov is in Ukraine. I hope you are safe, it is hard for me to imagine living in a country seeing so much needless destruction daily. Hoping you come through this free and un-harmed.

The interesting thing about this machine you described is it uses a hot stripper to chemically remove the solder and then the solder drops out of solution and is recoverable as well. There are many solder strip solutions available but most keep the solder in solution. Having it drop from solution, possibly as a function of saturation, pressure and temperature, is a big plus.

Does the company that made these devices still maintain a website?

 

[anachronism]

If I had to guess, I'd say that the rotating drum is on the inside, and that's the cover. Even when using low temperature to remove components, you are still heating the board up to a temperature that is going to offgas all kinds of fun fumes, so they have to send all of those fumes to a scrubber.

You'd be correct Sno. That's exactly what it does.

 

[haveagojoe]

I heard that the Royal Mint moved into escrap processing in order to protect jobs because of the reduced demand for coinage due to the rise of electronic payments

 

[Alondro]

View attachment 66384

Alondro makes a cake with this 'cocoa powder'....

"Hmm, it's really heavy. Did I forget the baking powder?"

 

[KalleMP]

Some of our members have mentioned heat to depopulate boards but likely on a smaller scale. This set up may interest some members

I have wondered in the past if a fluidised bed heater might work to remove components and possibly even incinerate PCBs without open flames and fuss.

There is a system that is used to remove plastic from screw extruder strainers and other things that heats the plastic in a bed of sand fluidised by hot air and the smoke is then captured to be burnt with excess air to heat the air going into the heated sand.
I do not remember if the heating was achieved by passing the exhaust from the smoke burner directly through the sand or by way of a heat exchanger.

Quick search found these two yt videos. I had seen one before that had some open flames dancing on the top of the bed where the hot smoke contacted air and autoignited.

 

[Taleeho]

Great contribution anarxi. I hope you are well.
There is a similar concept in a US or Canadian patent (hope I can find it again) which uses a "special liquid" described as "heat transfer medium." Perhaps it is oil-based; if so, high pressure seals might not be needed.
I would love to have a miniature of this processor to use for RAM sticks (in say 2-10 kg batch sizes). Any suggestion?
A huge amount of academic literature describes hydrometallurgical methods involving chopping/grinding/ dissolving using various solutions. Many involve multi-step processes to first recover copper, then get the gold. Lead, tin, and silver are problematic because they slow down dissolution of the valuable metal.
Thanks KalleMP for another way to skin the cat. Here's another: a Chinese patent for a purely mechanical system that scrapes the solder off (CN105818189B). I can post a translated copy if you're interested, but for me it's"better living through chemistry"
Best,
Lee

 

[Yggdrasil]

Great contribution anarxi. I hope you are well.
There is a similar concept in a US or Canadian patent (hope I can find it again) which uses a "special liquid" described as "heat transfer medium." Perhaps it is oil-based; if so, high pressure seals might not be needed.
I would love to have a miniature of this processor to use for RAM sticks (in say 2-10 kg batch sizes). Any suggestion?
A huge amount of academic literature describes hydrometallurgical methods involving chopping/grinding/ dissolving using various solutions. Many involve multi-step processes to first recover copper, then get the gold. Lead, tin, and silver are problematic because they slow down dissolution of the valuable metal.
Thanks KalleMP for another way to skin the cat. Here's another: a Chinese patent for a purely mechanical system that scrapes the solder off (CN105818189B). I can post a translated copy if you're interested, but for me it's"better living through chemistry"
Best,
Lee

There was a paper using molten salt to depopulate and pyrolize in one step.
The issue was all the glass fibers left by the process.
Any small component and foils was easily entangled and did as such not report to the molten Tin in the bottom.