What should be done next? please help!

[gaurav_347]

Gaurav, when I see your metal pile I only have one question, what are you doing with the plastics? I would suspect a lot of gold is contained in bond wires, locked in the epoxy plastics of the chips. When shredded I would suspect it would follow the plastic fraction.
Do you have a way of extracting the gold from the plastics? Have you tested the plastics for the gold content?

Maybe you only runs low grade scrap so this isn't an issue. I'm just curious.

I don't have any practical experience of running shredded circuit boards so I could just be wrong about where a large part of the gold ends up.

Göran

We do not shred the chips and the fingers are usually cut manually . The lab analysis of the epoxy did not show any precious metals in them. As of today we do not have the knowledge to remove gold from plastic. thank you

 

[gaurav_347]

You have said nothing of how you do the physical separation.

A little input as to how you do that and the types of equipment may be useful here.

I totally agree. It would be very helpful to know that.

In India the labor is quite cheap (4 usd/per day) so manual dismantling makes more sense instead operating the machines . The electronics that come in are first manually dismantled . The pcb and the wires are separated . The pcbs go into the shredder -->granulation of pcbs--> size separation--> plastic and metal separator--> magnetic separator

 

[gaurav_347]

Gaurav,

The answer Nick gave you based on your question is excellent and if refining in house is the route you choose, follow his excellent advice. If you can make your feedstock 95% copper it is relatively easy to scale up to the size electrolytic facility you will need.

But that is not the end of the story. Now you will be tasked with routinely incinerating some nasty anode bags to prepare the slimes for chemical refining. For this you will need incineration capacity and an acid refining capacity to process your precious metal into sale-able form. (ie. 999+ metal)

If you go that route, you will still have to find a buyer for your precious metals and they are always purchased at a discount so you are likely to be selling under market price.

Another option is to consider what you have. From my perspective that is one beautiful photograph!

Lets discuss the main thing a business sending out scrap to a refiner has to deal with, and that is how much metal is really in my material. I get requests from scrap collectors all of the time and all are unsure of the content. There are different ways a refinery can come to determine how much metal is in the scrap. Some incinerate to burn off the non metallic materials and produce a powder which contains precious metals and a pile of charred metal which is not as pretty as your pile. They then melt and assay the charred pile and have low grade copper based bullion to ship to a copper refinery.

Considering what you would have to spend to process 200 - 220 Kg a day followed by what you will have to do to recover the PM's and get paid for them, I would choose another option.

Remember most people who call themselves low grade refiners are really sampling houses. The one thing they do is produce a homogeneous sample. That is the most important thing here, a homogeneous sample.

Your little pile in the picture which has had the ferrous metals separated out is just a melt away from being that homogeneous sample. If it were me, I would first get a good melt furnace, one with a capacity of 250 Kg of your material so you can do melts on a single days production. They can be sampled while molten and poured into 30 Kg bars and you will have a representative sample of your entire days production. Now you need to do a fire assay.

There are many reputable copper refiners who give out very good rates for this material. The key is knowing your assay before you ship.

The step I outlined above requires equipment and analytical skills that you will have to have even if you go the electrolytic copper refining route, so it is a natural first step. If you ever do get to running your own refinery, not having the ability to analyze your material and control your in house refining accountability is the first step to going out of business. So the analytics are a must anyway.

Once you are producing your own copper based bullion bars in house and have the ability to assay them to settle your customer, it is an easy calculation to compare what it costs you to ship it to a copper refiner vs. the set up and operating expense of refining yourself.

I would think you will stop at melting and assaying your own bars and shipping to a copper refiner.

Shipping out bars that you know the assay of eliminates the wiggle room that shipping unquantified scrap gives to your refiner.

Thank you once again for your help . Really appreciate it. I will certainly pay heed to what you have said .

 

[4metals]

Start with the biggest

http://www.aurubis.com/en/

 

[alexxx]

I have very similar material that I wish to process myself.

I have tried many refiners so far, most of them will just actually sample / assay and ship to a bigger refiner such as Umicore, Aurubis, Xstrata.

I have never tried the big boys yet, mainly because you get your settlement 120 days after the material has arrived to their facility.
All the other small time refiners will mess with your numbers and recovery, that's just the way this business is conducted. They will always take advantage of small recyclers, period...

I have also found that all the big boys will quote your processing fees extremely high for doré bars, between 1.20 & 1.40 USD / lb, instead of the basic 0.40 - 0.80 USD / lb for circuit boards. It simply makes no sense sending doré bars to them.
So back to square one, sending the sorted boards to them... For me, this is a no brainer, no way, I have a feeling that I will get screwd (again)... Sampling and assaying shredded board wont be accurate too.

So, with the following assay, what would you pros do in order to recover Au, Ag, Pd, Pt, Cu, Sn & Pb ? All other recovered element is a plus of course, I would love to recover Sb in the process...

Cu 82.247%
Al 4.142%
Ca 0.006%
Fe 0.491%
Mn 0.026%
Pb 2.013%
Sn 7.711%
Ti 0.244%
Pt 0.003%
Pd 0.018%
Ag 0.921%
Au 0.064%
Si 0.006%
Zn 0.221%
S 0.114%
Ch 0.083%
As 0.021%
Ni 0.353%
Sb 6.542%

On my end, I would like to process 1 ton of circuit boards daily, I have that material on hand.
I'm able to shred, incinerate, ball mill, sieve, smelt to some extend...

The questions :

- Fluxing with a good flux recipe prior to casting the shirts might help getting rid of some base metals, and prevent a bit the cell contamination. Any recipe you guys might want to share ?

- How one would keep clean the cell, while recovering any contaminants such as Sn, Pb, Zn ? (the goal remains to replace the electrolyte as little as possible while having a maximum recovery)
Any element that could be plated out as a cleaning procedure ? What about additives, or cementation of unwanted base metals such as Fe, Al ?

- A first treatment of the alloyed beads in hcl might help too, any toughts on this one ?

cheers,

Alex

 

[g_axelsson]

I have also found that all the big boys will quote your processing fees extremely high for doré bars, between 1.20 & 1.40 USD / lb, instead of the basic 0.40 - 0.80 USD / lb for circuit boards. It simply makes no sense sending doré bars to them.
So back to square one, sending the sorted boards to them... For me, this is a no brainer, no way, I have a feeling that I will get screwd (again)... Sampling and assaying shredded board wont be accurate too.

Hi Alex, I don't understand your problem with a higher processing fee for the doré bars. It takes more circuit boards to make a bar. I don't know how much, but for the arguments sake let's say that it takes 4 pounds of circuit boards to make a pound of doré bar. Then the processing fee for raw circuit boards would be between 4x0.40 - 4x0.80 = 1.60 - 3.20 USD/lb while the fee for the bar would be 1.20 - 1.40 USD / lb. Still less than processing the raw cards.

So, with the following assay, what would you pros do in order to recover Au, Ag, Pd, Pt, Cu, Sn & Pb ? All other recovered element is a plus of course, I would love to recover Sb in the process...

Cu 82.247%
Al 4.142%
Ca 0.006%
Fe 0.491%
Mn 0.026%
Pb 2.013%
Sn 7.711%
Ti 0.244%
Pt 0.003%
Pd 0.018%
Ag 0.921%
Au 0.064%
Si 0.006%
Zn 0.221%
S 0.114%
Ch 0.083%
As 0.021%
Ni 0.353%
Sb 6.542%

I see two problems with your analyze, the total sum is >105% (and no oxides, oxygen) and what is "Ch"?

Göran

 

[alexxx]

Goran,

Cu is probably off since assayed on a later time with a different assayer.

Usually I get between 44 to 48% of alloy out of boards (clean ones of course, no excess steel, aluminum, batteries, etc..). Remains the pulp with some values, but that's another story...

And remember, in order to get the doré bars, there's some costs involved... 0.04 / 0.06 for shredding, another 0.05 / 0.06 for removing the magnetic fractions, incineration a few more cents, more expenses on smelting (gas, fluxes).

At the end, it will cost roughly 0.50 to get the bars. But you know exactly what you ship to the refiner or process yourself.

Leaving that 1.20 - 1.40 on the table + minimum lot size fee + % on the recovery + flat 2-3$ per Toz + penalties on berrylium + transport fees + tax & duties + delayed settlements + a huge risk of getting screwed by your refiner (and you will) is simply too much in my mind.

I still believe that for a medium size operation, and even a decent small operation, full recovery / refining in house in the way to go.

 

[alexxx]

no oxides, oxygen) and what is "Ch"?

Göran

Ch -> Cr

oxides & oxygen, should I assay for those as well ? How these are going to impact the recovery ?

 

[g_axelsson]

Thanks for the clarification Alex.

Do not take any of my comments as advices on how to do the refining as I'm only a hobby refiner. I was just pointing out the fact that there were no oxides in the analyze. In a melt from mixed metals I would expect at least some amounts of oxidized metal and that would have been added to the total too. Is the assay from one of your doré bars?
Quite often you see people analyze some crushed rocks with XRF and then stating that the metals add upp to 100% or more. In that case ignoring silicates, oxides, sulphides... and so on, just because a computer tells them it is so.

You must have a quite good source for your PCB scrap, 44-48% alloy is a quite high number. I did some research and found out some reported averages of PCB metal content:
http://cfsd.org.uk/seeba/TD/reports/PCB_Study.pdf gives 70% non-metallic and 16% copper 4% solder
http://www.emeraldinsight.com/content_images/fig/2170290306003.png 16% copper, 33% total metal
http://psrcentre.org/images/extraimages/312513.pdf gives 18.5% copper 9.35% other metals

If you have a source of scrap that makes it cheaper to send in full PCB:s instead of doré bars then you should naturally do it.

Göran

 

[4metals]

Alex

How were the samples generated to come up with these assays? How large was the lot of boards? What was the total sample weight? Were these numbers generated by an XRF?

Assuming a ton of melted metal parts. Are you really expecting to be paid for about $40 worth of lead? That is what it would be worth after you separated it, purified it and sold it. Less your costs of course.

Your solutions will get fouled up pretty quickly so you will have considerable waste treatment costs as well. This is only profitable on a very large scale, not the type of thing a small or medium sized collector should be looking to get into. Concentrate on producing a homogeneous sample and getting a reputable assay for the values.

 

[alexxx]

Alex

How were the samples generated to come up with these assays? How large was the lot of boards? What was the total sample weight? Were these numbers generated by an XRF?

We've generated this sampling from 2204 lbs of mixed medium/ periferal boards (especially the types of boards that are difficult to price & resell, no p3s, p4s, server boards in there). Results were obtained with an XRF. A fire assay was also conducted on Au, Ag, Pt, Pd & Cu. All the values were a bit lower than the actual XRF read. I still have many samples of this batch if anyone has any interest in playing with it.

Assuming a ton of melted metal parts. Are you really expecting to be paid for about $40 worth of lead? That is what it would be worth after you separated it, purified it and sold it. Less your costs of course.

I see it from another angle. If some elements could be recovered during basic cell cleaning / maintenance, these by products are worth something. If I can generate 40$ worth of Pb everyday and throw it into a drum to sell it at the end of month, my answer is yes, I will pay extra attention to recover these values. That extra 1200$ monthly of Pb will pay my electricity bill or 2 great seats for the next hockey game. Plus, when watching the price of Sn, I can't keep saying to myself, man, you need to get a piece of that non payable material. 130 lbs of Tin per MT of boards is a lot of money when you work on small margins like we do.

Your solutions will get fouled up pretty quickly so you will have considerable waste treatment costs as well. This is only profitable on a very large scale, not the type of thing a small or medium sized collector should be looking to get into.

Do you believe a contaminated solution could be cleaned by plating out Sn, Zn, Ni, Al and other elements, and than reused to some extend ? If the answer is yes, the waste treatment costs are nothing else than regular processing costs to clean the cell and recover other values.

Concentrate on producing a homogeneous sample and getting a reputable assay for the values.

That's indeed already a huge challenge, the exact same looking material won't give the same results, and without a homogeneous mix, it's really difficult to calculate your profitability.

One very important thing I forgot to mention, is that I wish to work on the maximum recovery, not the highest refining %. As long as I deliver to my PM broker 40%+ pure metal, I get paid the same. It doesn't matter much that the gold runs at 48% purity or 98,75% purity, I get the same price at the end. And I have no interest into working hard to get these triple or quadruple 9s. It would be even better to deliver an alloyed mix of Au, Ag, Pt & Pd into a single bar to my broker and get all my payable instead of 4 separate bars (avoiding the separate lot fees). The goal remains, getting the most out of your material (Cu, Sn, Pb for instance).

 

[Pantherlikher]

Not sure if this is a thought, or if you have access to this type of heater.
But years ago, my first go round with depopulating boards, I used this to heat the solder and dropped everything off. 5 seconds or so was enough to melt the solder to get everything off. Any longer and the board would start smoking. With some practice, I was popping boards like crazy leaving a big tray of stuff to seperate.

Think this would make more sense since labor is cheap. Spend the time seperating into each type so you can process or sell as is.

It would seem logical to me to process like items then making a mass of what ever is there.

I made short work of several hundred pounds of computer cards and mother(main) boards. Then made lots of piles of each type of part.

B.S.
Just a thought

 

[nickvc]

Alex there is no easy or cheap way to refine this material inhouse, the large refiners you quoted are all large base metal refiners with the precious metals been a by product, a nice bonus which comes from huge quantities of material not just circuit boards or e scrap.
If you produced a ton of dore bars a day they can add that to the hundreds or thousands of tons of copper they process daily which minimises the problems with fouling the solutions too quickly, they also have inhouse assay and testing available to monitor the solutions. The slimes which are where your values will be are going to be your next challenge due to the mix of metals within them and here you need experience and plant to handle them due to the toxicity of some of them and the complications of recovering the maximum value, the big boys no doubt have ways of recovering virtually all the metals which again pays with big volumes but which will cost big bucks to install and staff.
I have said it many times listen to 4metals he has been there and knows his stuff, if you want to cherry pick some materials to refine inhouse that's totally different to what you want to do. If you can melt your material and assay your bars then that's the best route in my opinion also, then ship to the big boys, yes it takes 120 days but advances can be made but interest is charged. I know margins are tight but don't be penny wise and dollar foolish, the cost to recover tin, lead or whatever else is going to be more than they are worth on a small scale, it might even be the case that even the big players ship on to other specialist refiners some of the materials as it isn't worth their while trying to recover them any further.
Spend your time and energies on what your good at, sourcing material and getting it to a state you ship with known contents, make sure assays are agreed before processing starts, and then nail a good deal with the big players, if you can increase your output I bet higher returns will be offered perhaps you can become a sampler of others materials and ship theirs aswell, having a few large regular customers ensures bills and wages are paid even for big companies.

 

[4metals]

Alex,

There is only one way to get a homogeneous sample, and that is to melt the entire metallics fraction together at the proper temperature. This involves having an induction furnace large enough to melt the entire lot. There are too many variables to do anything but estimate value any other way.

As far as expecting to recover other metals by processing in house you have totally missed the point in my mention of lead recovery. You make it sound like the $40 worth of lead is just sitting there as a bar to pick up and sell. Your costs to recover this lead and put it into sale-able form will undoubtedly exceed the $40 the lead is worth.

The one thing everyone who is in the refining business comes to learn in time is that a refinery is a specialty house. They have a few types of scrap that they specialize in and they set up for, and process those materials profitably. Then they have a list of refiners they have relationships with who can process the scrap types they can not run profitably. So essentially every refiner is a niche refiner. They also have an analytical ability to determine the quantity of the metals they are shipping so they do not ship blind. I have said it many times, If you cannot analyze it yourself, go with the material and witness the sampling.

Take a big copper refiner for example. They get in the bars you ship them and have given you rates to pay on the precious metals and copper. Their cells produce pure copper, that is their cash cow. Then they concentrate the precious metals in the slimes in sufficient quantities that it becomes cost effective to refine them in house as well.
Then they have to deal with the lead, antimony and tin that you want to be paid for. Those bad actors foul up their electrolyte and cost them to get rid of. They usually come out in the waste treatment sludges and if done properly they can be shipped to another refiner who pays on the metals in the sludges if they are part of the major content. If they are lucky it pays for what they put into it. They would rather live in a perfect world where the only contaminants in the copper were precious metals, it just doesn't happen that way.

Every refiner I know has a niche they work. Do they expand on their niche? Sure. But that comes after determining that there is sufficient feedstock and profitability in expansion. I do not know of many e-waste refiners (other than those who started as copper refiners and still produce copper as their primary product) who do everything in house and are profitable.

It would be nice to pick up that 40 pound lead bar out of the slimes and get paid for it, unfortunately it ain't that simple.

 

[goldsilverpro]

Things may have changed over the years but, when I used to ship refiner's bars, the only thing they paid for, besides the PM's, was copper. With some metals, if over certain percentages, penalties ($) were imposed. I remember that if nickel was over 5%, you drew a penalty.

 

[4metals]

Same is true today, lead is also on the list but percentages vary. Cadmium costs you big time too but if the precious metals do not come up to certain percentages they can enter the not payable list as well. Some refiners also have minimum deductions which hurt the smaller shippers.

 

[alexxx]

Things may have changed over the years but, when I used to ship refiner's bars, the only thing they paid for, besides the PM's, was copper. With some metals, if over certain percentages, penalties ($) were imposed. I remember that if nickel was over 5%, you drew a penalty.

Same goes these days. Same payable.
Penalties on excess Berrylium, Nickel, Mercury.

 

[gaurav_347]

Alex & 4metals,

What according to you is the best possible way to process pcbs for separating the epoxy and metals with low percentage of metal loss?

ps- thanks for all the help guys !

 

[4metals]

The best possible way is the way that is the most profitable and do-able by you!

There are different ways to get to the end you seek, all with some good and some bad features. In the end, if you think about this for a while, the manufacturers of the circuitry were not thinking about how complete recovery could be when the board reached the end of its useful life. As a result you have a mixture of materials that are bonded or masked or clad in such a way that they are difficult to separate by density separation.

That could make you say "Well then lets just incinerate!" But burning has its issues and the biggest is pollution. Then you end up with a powdered fraction and a metallic fraction, both going to separate refining processes. Oh, don't forget what values go up the stack or are caught in your bag-house.

Ok what about chemical leaching? Again some of the metals are masked and contact between a leach solution and the values is necessary. It works for some e-waste not for all.

Gaurav has a density separation process which makes a metallic fraction relatively free of plastics and epoxy. Where do the ceramic dice or semiconductors end up? They often have PM's sandwiched between layers of ceramic. Do your boards even have ceramic components? It is impossible to say you will or will not have precious metal value in the plastics/epoxy pile. It depends on too many variables. If your material has ceramic semiconductors I would think they could be separated out by density and processed as a separate stream.

Bottom line is no one system gets it all because when they were designed and manufactured there was little or no thought given to end of life recycling so you have an infinitely varied mix to deal with. Could you design a system to get it all? Maybe. Could you recoup the expense of the get it all system from extra recovery? Highly unlikely.

Welcome to the real world of e-waste recovery.

 

[kjavanb123]

I am reaching the same point as alex and gaurav, I have over 1000lbs of mixed boards mostly peripheal ones, which takes ages to depopulate with men power.
So my theory is to grind the boards to very fine powder, seieve and screen, then use a shaker table to separate metals and plastics or ceramics. This grinder is built in a way that could produce fine powder like flour from quartz ore in one hiur 100kg, and the builder already tested for different kinds of boards. It is sealed during grinding, for discharge there is a gate tht is open.
Now would shaker table be able to get some of the heavy precious metals, such as gold bonding wires, or tantalium? I will have the induction furnace with crucible capacity of 160lbs to do melt.
The closest major copper refinery to me, I contacted they have never had any copper dore bar produced from e waste, so I need to propose to them please kindly advise what should I write in that letter to the copper refinery? Tell them the kind of metals that might be in the dore bar produced from ewaste, and how they going to pay me?

Thanks
Kevin