# Lead, copper, silver?



## WestCoastProspector (Feb 28, 2015)

I've been told by a few members over at ScrapMetalForum that the solder on boards contains lead and silver. This brings up two questions:

1 - If I have IC chips that I need to incinerate, how can I ensure they are completely devoid of any lead-bearing solder?
2 - Is it economical to recover the lead? I have heard some larger operations use chemical baths to depopulate boards and do just that.

I've also been told that the boards themselves are fiberglass but also have a lot of copper in them. In general, is it economical to save this to sell to a larger refiner?


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## goldsilverpro (Feb 28, 2015)

Usually, the only metals of value to a refiner will be the precious metals.

The copper on a sheet of fiberglass board will be either 1 oz/ft2 or 2oz/ft2. Therefore, it will take from 8 ft2 to 16 ft2 of board material to make a pound of copper, if one-sided. That's unused, with no holes, traces, etc. - just a sheet of copper laminated to a sheet of fiberglass. When made into circuitry (with holes, traces, etc.), the copper weight will be much lower per ft2.

I doubt if any refiner would be interested in this as just a copper proposition. If there are decent amounts of PMs on the board, the refiner might also pay you something for the copper.


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## WestCoastProspector (Feb 28, 2015)

Thanks for the response GSP! That was definitely not the answer I was expecting (guess I was hoping I was sitting on the veritable copper-goldmine everyone's looking for). 

I had more been interested purely as a matter of principle; I hate throwing metal in the dump, and I'd rather waste money getting it recycled properly than know it's going to be buried needlessly under tons of overburden in a landfill for thousands of years. Still, that's a crying shame. The literature (if you can call it that) that I've been reading had me believing that the copper from the boards could constitute the bread-and-butter of an operation.

Thanks again.


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## Long Shot (Feb 28, 2015)

It is a crying shame West Coast and I agree. That brings up an interesting point though, what about all of the old, abandoned landfills? I am old enough to remember when scrap steel was $5 a ton and everything not wanted used to go to the "dump". Around here, several years ago, a company raised the proposal of "mining" two old landfills here. They had very sound environmental proposals drafted to do so. They were stopped dead in their tracks by one woman (who had nothing but time on her hands and a head made of wood) who raised a crusade against them. So now, the stuff just sits there, underground, in a swamp, leaching into said swamp. This person and the thirteen other houses across the road from the old sites have wells. They would have been doing themselves a favour by allowing the proper processing of the contents of the old fills. An old adage - out of sight, out of mind applies here I guess.


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## WestCoastProspector (Feb 28, 2015)

Yeah, I've heard about a company that wanted to do that at my local landfill. Trouble is in Canada (and I think most countries outside the US) landfills are publicly owned, which means anyone working towards putting that deal together will probably retire before it ever comes to fruition. 

It's funny you mention a lady like that. I browse a permaculture forum too, and there's a pretty big rift in the community right now of those who are gung-ho about a substance called biochar (look it up), and those who insist it's really just a pollution magnet that destroys forests and ruins the atmosphere. I think a lot of people in the latter camp are just grossly uninformed; they see smoke billowing out of a biochar retort and immediately assume it's going to be spewing ash and dust into the air. It's actually very clean technology, but the green movement has a real repulsion to that sort of stuff. It's almost instinctive. 

I bring this up only because I think it's funny the way people are often so fearful of what they don't understand. I'm just starting out, so I can't really say, but I'm sure a lot of you here on GRF have dealt with that a lot in the past, whether it be at the hands of the invasive EPA investigator, fire marshal, or nosy neighbor. 

I suppose we will just have to wait to see if landfill mining really takes off. If it does, we can all have fun laughing about all the thrown-away gold we find.


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## MarcoP (Feb 28, 2015)

I'm lucky I guess. At few hundreds meters from where I live I have a local WEEE depot organized by the council where I can take my fully depopulated boards, condensers and all leftovers. None of them ever been in contact with acids so I'm able to sleep well at night time. This is also why I prefer heatgun and sand bath over chemical baths.

Council trucks also comes ones per week to get plastic. Knowing that I can legally dispose of all the material, and for free, makes e-waste refining much easier, and as bonus it all gets properly recycled.


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## WestCoastProspector (Feb 28, 2015)

Doesn't the heat gun pose a health hazard with the lead?


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## rewalston (Feb 28, 2015)

At a technical school I went to many years ago. The school was an old Army Depot. Anyway, they buried old train cars one of the yards. They are about 50 feet underground. Well, when they buried them, they filled them with wire from an old telephone switching system. ALL of the wire that was buried were all gold. There is tons of that wire buried there, and the school/government won't let anyone "mine" it. Now THAT is a shame.

Rusty


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## MarcoP (Feb 28, 2015)

WestCoastProspector said:


> Doesn't the heat gun pose a health hazard with the lead?


It would if I exaggerate with the heat, anyways lead boils at 2022 K ​(1749 °C, ​3180 °F), and in any case that's not the only hazard. Burning of the board coating will also release poisons vapors.

Doing this outside or in a fume hood and paying attention to when the tin-lead solder melt is sufficiently safe.
Sand bath is always done outside with wind blowing from my back and heatgun is used indoor with a series of PC fans in series where the eventual smoke produced is sucked in with a piezo horn and pushed out the window with a flexible tube.

horn >, fan |, tube =
>||||==


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## FrugalRefiner (Feb 28, 2015)

MarcoP said:


> Sand bath is always done outside with wind blowing from my back and heatgun is used indoor with a series of PC fans in series where the eventual smoke produced is sucked in with a piezo horn and pushed out the window with a flexible tube.


It's safer to have the wind coming somewhat from the side. When it comes from your back, your body can create eddy currents that can cause some of the fumes to linger in front of you. I try to keep the wind quartering in from behind, not directly behind.

Dave


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## MarcoP (Feb 28, 2015)

FrugalRefiner said:


> MarcoP said:
> 
> 
> > Sand bath is always done outside with wind blowing from my back and heatgun is used indoor with a series of PC fans in series where the eventual smoke produced is sucked in with a piezo horn and pushed out the window with a flexible tube.
> ...


That's indeed a great point Dave and I'll take that into consideration but luckily the wind often change direction. Thinking about it now I had the issue you talk about and I think I instinctively moved a little.


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## METLMASHER (Feb 28, 2015)

"I think I instinctively moved a little." :shock:


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## WestCoastProspector (Feb 28, 2015)

MarcoP said:


> WestCoastProspector said:
> 
> 
> > Doesn't the heat gun pose a health hazard with the lead?
> ...



That's interesting, is this how commercial refiners depopulate the boards? I've always knocked flat packs off myself and pulled off tantalum caps and wedged MCCs off with a chisel. It always seemed terrible inefficient, particularly for MCCs. I could never find out how people managed to do it and make it worth their time.


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## g_axelsson (Feb 28, 2015)

Commercial refineries don't depopulate boards, they shred, sample and smelt it to produce copper bars that are refined, producing a precious metal slime that is further refined. Large smelters as Boliden or Umicore is recovering a lot of the metals in the boards, gold, silver, palladium, platinum, lead, tin, cobalt, zinc... and so on.

I think you mean MLCC:s, Multi Layer Ceramic Capacitors.

Göran


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## WestCoastProspector (Feb 28, 2015)

g_axelsson said:


> Commercial refineries don't depopulate boards, they shred, sample and smelt it to produce copper bars that are refined, producing a precious metal slime that is further refined. Large smelters as Boliden or Umicore is recovering a lot of the metals in the boards, gold, silver, palladium, platinum, lead, tin, cobalt, zinc... and so on.
> 
> I think you mean MLCC:s, Multi Layer Ceramic Capacitors.
> 
> Göran



If that's what they are I've been collecting the wrong stuff. I'm talking about Monolithic Ceramic Capacitors.


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## MarcoP (Mar 1, 2015)

WestCoastProspector said:


> g_axelsson said:
> 
> 
> > Commercial refineries don't depopulate boards, they shred, sample and smelt it to produce copper bars that are refined, producing a precious metal slime that is further refined. Large smelters as Boliden or Umicore is recovering a lot of the metals in the boards, gold, silver, palladium, platinum, lead, tin, cobalt, zinc... and so on.
> ...


Stacking multiple layers creates a multi layer monolithic block.


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## g_axelsson (Mar 1, 2015)

I dug a bit deeper and MCC is a seldom used acronym for almost the same component as MLCC. As I work with electronics I always use and see the MLCC acronym, in the technical literature and on manufacturers websites MLCC is used almost every time and MCC in only a few cases. The one I found that used MCC and spelled it out it used it for Multilayer Ceramic Capacitor.

Monolithic ceramic capacitor is also used for a single ceramic dielectric between two external metal electrodes and it seems like a lot of the instances it is used it is for this type of capacitor.

Searching for MLCC on the web gives a lot more and better results than using MCC.

Göran


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## Geo (Mar 1, 2015)

WestCoastProspector said:


> g_axelsson said:
> 
> 
> > Commercial refineries don't depopulate boards, they shred, sample and smelt it to produce copper bars that are refined, producing a precious metal slime that is further refined. Large smelters as Boliden or Umicore is recovering a lot of the metals in the boards, gold, silver, palladium, platinum, lead, tin, cobalt, zinc... and so on.
> ...



It's the same thing.


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## rickbb (Mar 2, 2015)

WestCoastProspector said:


> I've been told by a few members over at ScrapMetalForum that the solder on boards contains lead and silver.


 This brings up two questions:

1 - If I have IC chips that I need to incinerate, how can I ensure they are completely devoid of any lead-bearing solder?
2 - Is it economical to recover the lead? I have heard some larger operations use chemical baths to depopulate boards and do just that.
quote]

Lead has not been used in electronics solder in a long time, unless you have some really old stuff you don't have any lead, (there may be some lead present, but it's not supposed to be there). Today's solder is tin/antimony. Only occasionally you will find some tin/silver for some special application, but it's not common on most PCB's. 

Remember that most of the boards you will come across are made in China and made as cheaply as possible. They aren't going to use silver solder unless they have to. And they will use as little as they can get away with. The days of over engineering a part to make sure it does not fail are long gone.

One of the popular books on refining, says you should approach e-waste refining as a copper recovery/refining process. If you can make a profit off the copper then the PM's are icing on the cake. Copper by far is the most common metal in e-scrap, almost 60% by weight according to some estimates.

The only reason to depopulate would be if the board has gold plating to strip, as in cell phone boards, touch screen controller boards, or to recover high value components like MLCC's, tantalum capacitors, and so on.

The large operators have the economy of scale in their advantage. They can grind the whole thing up and process the pulp in large enough batches to make money on the copper alone. Then work on recovering he various PM's.


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## WestCoastProspector (Mar 3, 2015)

Interesting. Would you say it's economical to use a heat gun for the MLCCs?

I've heard some depopulate motherboards, but I didn't think these had any plating on them that would make it worth doing, just a lot of MLCCs and flatpacks.


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