Mechanical depopulation of PC Boards

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snoman701

Well-known member
Joined
Oct 8, 2016
Messages
2,108
Location
SE MI
First, while I am a new member, I have very little interest in the PM content of Ewaste. My interest is more in the big picture. I like the recycling industry. While I am a "back yard guy"....I am also a prototype and design company. My point in this...please skip the "read Hoke" comments. I do recover and refine silver, largely as a secondary operation...and enjoy it. And while I am saving gold components, the chemistry side requires such high control and confidence in methods that I prefer to avoid. See my previous post in safety for a good example! :lol:

So herein is my "method". In the past, when I have entered a field, it has begun with "here's the current methodology". In some cases this involves reading a stack of journal articles. In others, it means working on the floor next to the guys that actually know what the hell their doing. The recycling industry is new to me, even though I've been involved with it for ages (I am a collector of anything, I have spent countless hours in scrap yards and recycling yards finding value in other peoples junk).

My point, I think this field is young in it's development of technology. The methods are brutal. (and sometimes brutal is best)

Wherein my confusion lies, is that there seems to be a gap between mechanically stripping boards via labor intensive processes and cherry picking the high yield components with heat gun and labor and sending the remainder through the wood chipper used in Fargo. (and yes, I'm very knowledgeable of modern grinding techniques, that was sarcasm).

The recycling industry is very owner operator centered. It's collected, it's categorized, and it's shipped. There is very little field based material upgrade in the bigger yards. It's just shipped. At the smaller yards, it's labor intensive. The good ole boy that could have the engine out of the chevrolet in ten minutes, while preserving all of the mechanical components....all before you can even find your 13 mm wrench.

So my question is the following...I have heard of industrial "desoldering" machines. I have seen chemical processes to strip the solder. What I have not seen is a time effective method of mechanically stripping components of a PCB to not only conserve integrity of the board, but also the original integrity of the components.

And while companies such as boardsort (which I love) would argue that the most efficient method of recovering values is to shred it, then pyrolize the whole damn pile of junk, I still question if that is the most cost effective method, let alone environmentally friendly method.

The capillary strength of solder is quite substantial, so I recognize that the necessity of breaking that force
 
OK, Ive read that post and I've heard what you're saying.

Now. Mechanical depopulation of boards to concentrate the PM bearing materials is not young in the industry. It's done on commercial scales, and not involving intensive labour. For the small scale recycler the cost/benefit analysis is not good. Whether you choose to buy equipment to do it or choose to cherry pick certain components then remove those individually, then once you add in your own time the cost makes it inefficient.

Please note I am answering this question on a commercial basis, NOT for the guy who is taking in free e-waste and doing it in their spare time. Although the point about the worth of your own time does remain the same. This is something others have alluded to, Deano for one. I'm also not entirely sure what you mean by having very little interest in the PM content of Ewaste. Given there are a lot people on here who make a good living from this, along with others who make a great personal income from it could you please explain your thinking further perhaps?

To answer your specific point about a time effective method of removing components from a board whilst retaining the integrity of the board and the components:

There is machinery available to do this, its the same equipment used in workshops to replace board level components. It isn't cheap and since I am answering from a commercial perspective you would have to be picking and choosing your material to make it financially viable.

I would be asking the question as to your end game and goal and balancing your desired outcome with the reality of the input required in whichever path you choose to take. If you could explain further it may be that I can help more.

Jon
 
Jon,

Thanks for the response. You actually sound like you have just the knowledge I'm seeking.

On a commercial scale, how are boards depopulated?

Any recommendations for understanding the commercial process of recycling say, "a motherboard".

By not interested in the PM's...I mean simply, I don't have the gold bug. I just have a very strange interest in the process, and would ultimately like to work within the field if I can find a niche.

Thanks again,

-Jacob
 
anachronism said:
OK, Ive read that post and I've heard what you're saying.

Jon

Like Jon I hear what you are saying :mrgreen: :lol:

Don't have time to post a reply right now as I just used up my posting time replying to your other thread (safety) & have to get headed out to the lab to AR a batch of CPUs that should be done with there HCL pre-treatment now

Will be keeping an eye on this thread to see what Jon (& others) have to say & try to do my best to post a reply later today &/or tomorrow morning (no promise as I am working a good size batch for a client right now & he comes first)

Kurt
 
From memory the big boys frag mechanically and magnetically sort and then smelt using excess copper, the bars produced are assayed and sent to copper refiners for settlement of the values, again from memory certain elements are paid for and some carry penalties depending on the percentage, settlement takes 90 days or longer but you can take advances which carry interest which is deducted at final settlement.
This was all detailed some time ago by 4metals I believe but I'm not sure any better large scale process exists so perhaps he can add any further details.
 
snoman701 said:
Jon,

Thanks for the response. You actually sound like you have just the knowledge I'm seeking.

On a commercial scale, how are boards depopulated?

A variety of processes, utilising shredding and sorting using a combination of eddy current separation, magnetic separation and shaker tables and flotation tanks.

Any recommendations for understanding the commercial process of recycling say, "a motherboard".

This link provides some good references and outbound links to visit and learn from. http://www.appropedia.org/Metal_reclamation_and_recycling_of_electronic_waste

By not interested in the PM's...I mean simply, I don't have the gold bug. I just have a very strange interest in the process, and would ultimately like to work within the field if I can find a niche.

Before you think of a niche think of the cost required to set up in that niche. People who want to set up concentrating the values from ewaste fall foul of the base fact that unless you are dealing with hundreds of tonnes of raw product per month the whole concentrating process nets you less money after costs than sending the raw material straight into a refinery. You should have plenty of resource here to look at an research now because one site will lead you to another and before long you'll have 20 browser pages open.

Thanks again,

-Jacob
 
nickvc said:
From memory the big boys frag mechanically and magnetically sort and then smelt using excess copper, the bars produced are assayed and sent to copper refiners for settlement of the values, again from memory certain elements are paid for and some carry penalties depending on the percentage, settlement takes 90 days or longer but you can take advances which carry interest which is deducted at final settlement.
This was all detailed some time ago by 4metals I believe but I'm not sure any better large scale process exists so perhaps he can add any further details.

As Nick said. To add some meat to the bones:

If concentration of PMs is the goal then once the processes laid out in our posts above have been followed the copper bearing product goes one way and the PM bearing product goes another, whilst the base metals and plastics go in their own directions.

90 days from shipment is a good benchmark. That's what I get. You could send material to a packager and get some of your money on delivery however the trade off is that you pay commissions to a third party and your returns are lower. It's about cash flow. If you can tie up $300,000 (or a LOT more) and wait for the refinery you will get more profit.

Dealing with refineries and sorting the wheat from the chaff is an acquired skill in itself. Suffice to say unless you have a decent amount then they won't deal with you and a packaging company becomes your only route in until you have the capital to bulk up a full load yourself.
 
anachronism said:
Before you think of a niche think of the cost required to set up in that niche. People who want to set up concentrating the values from ewaste fall foul of the base fact that unless you are dealing with hundreds of tonnes of raw product per month the whole concentrating process nets you less money after costs than sending the raw material straight into a refinery. You should have plenty of resource here to look at an research now because one site will lead you to another and before long you'll have 20 browser pages open.

I do not disagree with this post...in fact, I wholeheartedly understand it. However...

It is based upon an expectation of losses that seem fit and acceptable. When you simply sort conductive from non-conductive, and magnetic from non-magnetic....I would imagine you lose a majority of the contact losses. The smudges, the smears, the pieces of plastic with gold wires still embedded.

From a hypothetical. If one were to painstakingly remove every component from a "batch" of motherboards. Then process the concentrated values using accepted technologies....and process the actual PCB using accepted technologies.....and compare it accepted technologies of shredding, sorting and refining, would the concentrates yield greater value?

I get it, it's a complete change from accepted methodology. But simply said, in reading differing opinions of "this is what I get when I process in my shed" vs "this is what they get per ton"....the numbers appear VERY VERY different.

One of the things I gathered from Mario when I initially started selling to boardsort, is that the benchmarks weren't even there. They had no clue what to expect...so they had no clue if their sorting methodology was good, etc.

And yes, completely understand 20 open browser windows. I have 7 on this tab alone.
 
You're correct in that before you start to do this there are no benchmarks. You know that there are larger margins that you would be offered if you trade board but until you have hard data from your own loads it really is a case of licking your finger sticking it in the air and guessing the wind speed and direction. That hard data allows one to to set buy prices based upon the known range of returns for any given product stream. The main reason that nobody is going to release that information is because it's taken them hundreds of thousands of dollars in risk to get those numbers coupled with the commercial advantage those numbers provide. Someone doing this professionally could look at quite a lot of streams of material and make an informed decision on the ppm yields of Au/Ag/Pd/Pt/Cu to within 25ppm.

"From a hypothetical. If one were to painstakingly remove every component from a "batch" of motherboards. Then process the concentrated values using accepted technologies....and process the actual PCB using accepted technologies.....and compare it accepted technologies of shredding, sorting and refining, would the concentrates yield greater value?"

No. The PM value is the same regardless. You would just spend more time to get the same result and the net effect would be less net profit.

"I get it, it's a complete change from accepted methodology. But simply said, in reading differing opinions of "this is what I get when I process in my shed" vs "this is what they get per ton"....the numbers appear VERY VERY different."

Yes they do. The "this is what I get per tonne" figure is higher than what is obtained in your shed.
 
To put it in very simplistic terms the cost and time to home sort and refine e scrap against what a large refiner or buyer will pay makes it a losing proposition, that is why most members cherry pick their scrap and sell on the rest, you can make money from refining at home but you either need free e scrap or karat gold or gold filled which means having the finances to buy up front or be lucky to have a constant source of free scrap.
Many have tried to reinvent this particular wheel and all eventually give up or move onto better things, spend time reading and learning the various methods employed to recover and refine the values and then determine if there is a better method for home refiners.
 
So in the case of boardsort (easy example)....he's able to be successful because he's invested the money in the product and knows what any given category should historically produce, and thus can know how much he can safely spend to get the margins he wants....and all of this without anyone else, except those competitors that run their business the exact same, really knowing what those margins are.

Back to depopulation.

It is completely unnecessary and is done just to, in effect, capture the highest yielding parts and send the waste stream elsewhere. In terms of commercial scale processing, they could send a load of brown board in with a load of memory, and expect to get out exactly what they sent in? ie: the concentration / sorting is simply done for the packagers side, to develop the benchmarks. It offers no real advantage once it enters the furnace? (other than from the packagers side again, to present expectations of yield)
 
snoman701 said:
So in the case of boardsort (easy example)....he's able to be successful because he's invested the money in the product and knows what any given category should historically produce, and thus can know how much he can safely spend to get the margins he wants....and all of this without anyone else, except those competitors that run their business the exact same, really knowing what those margins are.

Absolutely 100 percent correct. You've nailed it.

Back to depopulation.

It is completely unnecessary and is done just to, in effect, capture the highest yielding parts and send the waste stream elsewhere. In terms of commercial scale processing, they could send a load of brown board in with a load of memory, and expect to get out exactly what they sent in? ie: the concentration / sorting is simply done for the packagers side, to develop the benchmarks. It offers no real advantage once it enters the furnace? (other than from the packagers side again, to present expectations of yield)

Again you've got the concept right. You could mix rubbish in with good yield product and know in advance the likely return. Given that, you wouldn't mix the two products because you would potentially get penalties applied across the whole batch which would penalise you on the better product. European refineries operate differently from far Eastern ones. The model and methods of those in the far east are far better for the guy getting the product. The hard bit is getting into those refineries.
 
snoman701 said:
So in the case of boardsort (easy example)....he's able to be successful because he's invested the money in the product and knows what any given category should historically produce, and thus can know how much he can safely spend to get the margins he wants....and all of this without anyone else, except those competitors that run their business the exact same, really knowing what those margins are.

To expand upon my answer posted above. You have read between the lines extremely well in my previous posts. In fact I initially included a line about people "in the know" talking to one another and chose to delete it. Yes if I was to have a conversation with Mario, we would probably feel comfortable discussing the yields because we both know the hard figures. Neither of us would have anything to lose because it's all there in black and white on our refinery returns. It's not about being clever, it's about actually getting on and doing it and being prepared to take the risk.
 
Ok, so a serious question in regards to the development of the benchmarks.

I am very used to other fields which have the ability to run much smaller batches. Is the large batch just the scale of economy? Costs the same to run a truck full as it does to run 100 lbs...so might as well make it worthwhile? Do the pilot plants not exist for running smaller loads?

I can also look at his purchase price numbers and recognize that there is a certain "game" to it. Penalties in some categories and "rewards" in others....possibly even a bit of "what does he know that we don't"
 
No it doesn't work the same in smaller quantities. For smaller quantities you pay a lot more. the logic is simple - it costs the same to fire up the refinery for 100Kg as for 5 tonnes.
 
I think I am still a little confused as to the "refinery" vs the "smelter".

Refining side...I'm good (at least from a metallic alloy to marketable alloy perspective)

Smelter, not so much....and is this generally expected to be hand in hand with the refining side. Most smelters also refinery, but not every refinery smelts?

What goes in to the "furance"? Is it just non-ferrous metallic scrap with trace amounts of plastic? Or are the brominated boards themselves actually going in? The exhaust is scrubbed either way, but if the plastic is mechanically sorted prior, then you are not creating as hazardous of waste stream as you would be if you were scrubbing the bromine out after incineration.
 
Ok...that makes sense.

Any comment on the plastics, or unable?

Either way, thank you for all of your knowledge! You've helped me along quite a bit! I'm down to only 17 open screens!
 
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