# 1190lbs of mixed Peripheral boards



## kjavanb123 (Jul 14, 2014)

All,

I purchased this load at $1.50/lbs. Now should I was thinking the following methods, please advise,

1- Grinding the boards to fine powder.
2- Screen
3- Separate metals from fiber glass and plastics with shaker table.
4- Melting metallics into anode, assay and sell to copper refinery.

Or

1- Four workers using oscillator chisels to remove components
2- Separate gold plated, and gold filled, MLCCs, Al caps.
3- Cyanide leach gold plated, drop the gold
4- Grind the gold filled, screen, shaker table, melt the concentrate, refine it.
5- Grind SMDs, Ta caps, screen, using shaker table to concentrate the Ag, Pd, Ta, Ru.
6- Grind boards, shaker table to separate copper, tin solders from junk.
7- Dissolve tin solers, melt copper.

Last time it took 500lbs of telecomm boards, 2 workers using chisel and sledge hammer to depopulate them in 6 days.





Thanks
Kevin


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## Clneal2003 (Jul 15, 2014)

Dang that's a lot of work. Good luck. I'm thinking you'll encounter one of two scenarios: 1) you hire others in which they'll consume some of your revenue cutting into profit... Not too mention the learning curve of training how to handle PM's and come out a little in the green, or 2) you spend hours and hours yourself making sure you get everything processed the proper way as to recover and refine the most gold. I can't imagine the task you have ahead of you. 

Keep in mind I'm on three hours of sleep and my two year old is sitting on my left arm while I type this. 

Good luck and post your results. I'm thinking in order to justify hiring out for help... You would need a constant flow of cash and boards.


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## Lou (Jul 15, 2014)

Jeez, hammer and chisel?

Ever heard of a planer? Or air tools?


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## alexxx (Jul 15, 2014)

How efficient is the shaking table on unburned material ? Don't you believe it would be better to incinerate everything prior to gravity separation, in order to recover everything that is still trapped into fiber glass or epoxy or any other resin ?


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## Anonymous (Jul 15, 2014)

I'd have just sorted and sold the things and saved myself the hassle Kevin.


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## kjavanb123 (Jul 16, 2014)

Lou,
My first choice had I gone to option 2 was to use oscillator multipurpose tool, but this would be a lot of work.

Spaceship,
That is my last resort, since I bought this at the bargain price locally.

Alex,
The type of grinder that is built for me has the same concept as a blender machine, but using a hammer made of truck suspension which is a very tough steel, it has two that are installed on top of each other forming a X shape when you look at from the top, this connected to a 5hp, 1400rpm motor, as I said again, it is yet to arrive at my shop, I am expecting a low mesh output from this grinder
This fter being through a couple of vibrating seieves, would go through a shaker table, I receieve quota from Action Mining, and alsoo from Mt Baker Mining, I await to recieve my grinder first to send samples to them to see what concentrate, midleing and tailing look like and assay.
I already sent a fax to the only copper smelting in the region which is in Iran, and hopefully by the time they respond back I have the copper anode bar ready to be tested.


Thanks
Kevin


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## 4metals (Jul 16, 2014)

Can you dissolve the solder with liquid caustic and peroxide? Then the components should fall off. 

Then rinse dry and sort the pieces for processing.


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## Clneal2003 (Jul 16, 2014)

Pb & Sn are problematic. I'm not sure if caustic would work. Alternating hot HCl and H2O will work on the Sn and Pb. It's recommended to soak solder in hot HCL then scrape off when possible. Just don't use HNO3 as it will turn the Sn into a white paste like meta stannic goo...


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## kjavanb123 (Jul 16, 2014)

4metals said:


> Can you dissolve the solder with liquid caustic and peroxide? Then the components should fall off.
> 
> Then rinse dry and sort the pieces for processing.



I did just that for 100kg load, but instead caustic and peroxide, I leached them in hcl, and some of the MLCCs came off to the bottom of bucket, but the rest of them were scraped off manually. Plus if there was any plastic it turned to mess, have not tried caustic and peroxide but does it effect the plastic and turn it to gooey mess? 



Clneal2003 said:


> Pb & Sn are problematic. I'm not sure if caustic would work. Alternating hot HCl and H2O will work on the Sn and Pb. It's recommended to soak solder in hot HCL then scrape off when possible. Just don't use HNO3 as it will turn the Sn into a white paste like meta stannic goo...



Again since volume is over 1000lbs, the acid waste solution generate a lot of waste, and hcl and plastic covering for pins would also melt and absorb within itself some of the SMDs.

But if shaker table can sort based on specific density heavy ones like gold, tantalium or palladium, silver end up in concentrate, and copper and its alloys end up in mid section.

Another method, would leach the boards as it is in a large tank using cyanide, this would take care of all plating, sockets, drop the gold by zinc or plate it on SS, after soaking them in NaOH and peroxide to remove the traces of cyanide and. Possibly remove the solder, grind the boards, remove ferrous, melt non-ferrous.

Regards
Kevin


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## nickvc (Jul 17, 2014)

Clneal2003 said:


> Pb & Sn are problematic. I'm not sure if caustic would work. Alternating hot HCl and H2O will work on the Sn and Pb. It's recommended to soak solder in hot HCL then scrape off when possible. Just don't use HNO3 as it will turn the Sn into a white paste like meta stannic goo...




I have to say if 4metals suggests something I'd sure try it even as a test batch to see the results...


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## Anonymous (Jul 17, 2014)

4metals said:


> Can you dissolve the solder with liquid caustic and peroxide? Then the components should fall off.
> 
> Then rinse dry and sort the pieces for processing.



Would this also have the added benefit of removing solder mask from the boards 4metals? 

Jon


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## kjavanb123 (Jul 17, 2014)

nickvc said:


> I have to say if 4metals suggests something I'd sure try it even as a test batch to see the results...



I am sure his suggestion are flawless but I am concern about the massive amout of waste solution it will produce since this load is 1400lbs.

Thanks
Kevin


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## 4metals (Jul 17, 2014)

When you try to run with the big leaguers, you have to come prepared to play the game!


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## kjavanb123 (Jul 17, 2014)

4metals,

Thanks for your post, I read here about using 50% caustic solution mixed with 35% hydrogen peroxide would dissolve solder, is that the same formula you are talking about? Can Tin/lead be recovered from it and what is the waste management for the solution?

I did recover some 4 lbs of solder from leaching boards in hcl, but would the same electrolyt set up works with NaOH?


Thanks 
Kevin


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## 4metals (Jul 17, 2014)

I have never wasted my time or energy to recover base metals other than copper. And copper only because we had so much of it. The hydroxide used for the solder stripping process can be re-cycled to raise the pH of waste refining acids to drop all of the base metals as metal hydroxides before filter pressing. The tin, lead, zinc, and copper all end up in the filter press cakes. 

I am sure some solder masks are removed by strong caustic but I am also sure that not all of them are. The chemical de-soldering allows for magnetic separation and allows easier sorting of stripped (depopulated) boards and chips. From there different processes are used for recovery.


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## kurtak (Jul 17, 2014)

Kevin

I don't think you are going to be able to get away from the incineration/smelting process for processing large lots of CBs no matter how fine you are able to shred/granulate un-incinerated boards --- shed - incinerate - smelt is how the big boys do it

here is a link to a company that shows some good videos - http://www.advchem.com/prod.php?id=25 

on the right hand side of the page you will see "Refining Capabilities & Equipment" & under that you will see a list - melting, shedding, incineration, etc. those are the videos --- click on the incineration one - its the more complete video of there process

Kurt


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## kjavanb123 (Aug 2, 2014)

This just came in, I contacted the copper refinery over in Iran after I told them about how I can produce copper anode with 95% plus copper content and PMs, gave them some rough numbers, and they told me their anode must be 99.7% pure to be converted to 99.99% ?? I read 98% or 96% would be the ideal content. So they are not interested unless my dore ran 99.7% pure how much copper is needed?

Regards
Kevin


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## lunker (Aug 2, 2014)

Kevin,
Not sure if this would help but I use a small hydraulic cylinder and a sharpened blade from a loader. I mounted a solid bar of steel and the blade together and used a clean circuit board as a spacer. The cylinder has a flat bar with a small groove welded on it. The board is placed in between the blade and the steel bar. The groove holds the board and I simply press the board through. The chips etc shear off. Leaving the board and solder etc to be sold or recycled. You lose the pin bottoms in the board. But eliminate the bulk of the material. If I ever figure out how to post a pic I'll show you. 
Scott


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## kjavanb123 (Aug 2, 2014)

Scott,

Thanks for your post, I think I have see a post few years ago here talking and showing pretty much what you described instead of vertical he used horizantal position and hydrolic press to depopulate the boards.
However they may seem practical for few kg or lbs of boards when one reaches couple hundred kgs or thousand lbs range options to process them economically comes down two very few, incineration, selling or in my case I am trying more "green" method of shredding grinding sorting classifying follow by gravity separation the. Melt to copper dore

Best regards
Kevin


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## Claudie (Aug 2, 2014)

lunker said:


> Kevin,
> Not sure if this would help but I use a small hydraulic cylinder and a sharpened blade from a loader. I mounted a solid bar of steel and the blade together and used a clean circuit board as a spacer. The cylinder has a flat bar with a small groove welded on it. The board is placed in between the blade and the steel bar. The groove holds the board and I simply press the board through. The chips etc shear off. Leaving the board and solder etc to be sold or recycled. You lose the pin bottoms in the board. But eliminate the bulk of the material. If I ever figure out how to post a pic I'll show you.
> Scott



I would like to see a picture of that.
You can use a photo hosting site such as photobucket.com


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## resabed01 (Aug 2, 2014)

Id like to see that too. It would sure beat the air chisel I use now. It's too labor intensive and somewhat slow.
With a hydraulic shear I could clean a box of motherboards in a few minutes instead of hours.

Question; Do the boards ever get stuck between the bar and blade?


Scott, If you're having trouble posting pictures, I'll help you out.... send me a PM


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## johnny309 (Aug 7, 2014)

Have a question....I have done some research...not sure if all the PCB producers use the same process,but the copper trace an a PCB is 30-40 uM bonded with a "glue"(except for computer boards and cellphone boards...5 layers...another story)....so the question is:
Etching the copper trace or just dissolve the "glue"?

Second question......:
Most boards are fiber glass ....so...when you burn some stuff like this.....your waste stream is big....and have to deal with C and Si...and precious metals...not to mention the high temperature that you will have to achive(cost of energy).....in the process you will loose TIN(3xcooper price....and more much present on a board than copper,as weight)......

P.S.: People tend to dispose all the thing they do not need....think twice...if you ever have the guts to work a complete shift in a mine 2 Km below earth surface just for 10 Kg of copper ......do not go only for gold,silver.....go for clean water......you can put poison(copper salts damage plants)in your house....just for the sake of a few dollars.


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## lunker (Aug 8, 2014)

With regards to the shear, I'll dig it out and get my wife to post some pics. I'm better at destroying technology rather than using it. As for the air chisel. I use a steel table that's on a decline. Welded a small piece of angle iron to hold the board and have a floor vent elbow at the bottom to divert the falling parts into a 5 gallon pail. I then start w all the boards and go through removing just one type of component That way you have just say flat pack or chips in the pail. Instead of a mixed mess you have to sort later. 
I also read that acetone was once used to dissolve the fibreglass resin. Think it would be messy toxic and very flammable option. Also believe it's very carcinogenic.


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