New Technique for Recycling PCBs

MattSparkes writes "PCBs from discarded computers, cellphones and other devices could be recycled less harmfully using a technique developed by researchers in China. Unlike current methods, it can be used to reclaim metals such as copper without releasing toxic fumes into the air. Only a small numbers of PCBs are currently recycled."

Bulding materials?

They want to compact & use the non-metallic parts as building materials.

This raises the question: Will there still be toxins in these compacted objects? And will they come out when the structure is eventually demolished?

Even concrete has all kinds of nasty that leeches out when you turn it into a pile of rubble.

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The plastic used for most PCB's is polyvinyl chloride, which in itself isn't particularly toxic under most circumstances. It's in common use these days for plumbing fixtures and the like, as well as for PCB's. However, if you burn PVC plastic, it gets co

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However, if you burn PVC plastic, it gets converted into some particularly nasty dioxins and furans which are dangerously carcinogenic.

Thus, if you happen to be inside one of these buildings when they catch fire, you are really screwed!

Re:Bulding materials?

> Thus, if you happen to be inside one of these buildings when they catch fire, you are really screwed!

Yes, if you ever find yourself inside a burning building, my advice to you is to get out immediately.

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I read an article in Harper's Magazine about a bunch of people living in a garbage dump in the Philippines. The kids gather all the computers into a pile and then light it on fire. They stand around the fire and poke it so everything plastic burns. Then th

Re:Bulding materials?

In the Philippines they really only burn insulated wire, car tyres, and anything with springs like beds and chairs. Electronics rarely make it to the dump sites these days, too much value to be thrown away, they usually end up in repair shops, stripped for spares. (I do a lot of work for a charity here on Smokey Mountain dump site in Manila)

You are right about the garbage falls, though it's usually the land slides that take out 200 people or more at a time.

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Here is the article:

http://harpers.org/TheMagicMountain.html [harpers.org]

It's a fascinating look at the underworld of the Garbage Dwellers. It's really sad, horrible, horripilating, and awful.

The author says a recent garbagefall killed hundreds of people. And you're ri

Re:Bulding materials?

The plastic used for most PCB's is polyvinyl chloride

No it isn't. PCBs are made either from glass fibre (FR4) or resin-bonded fabric (CEM1). PVC would soften too much at soldering temperatures.

Re:Bulding materials?

Right, now that I've looked it up, but the issues are still the same it would seem. Burning these types of boards to get at the metal is still something that you really don't want to do. They typically use brominated flame retardants [wikipedia.org] on these boards, which while they are generally inert and non-poisonous in their normal state, when burned they also produce deadly carcinogenic fumes, especially in the presence of copper [haloclean.com]. That makes that ingenious technique described in the article all the more useful: it separates the metallic and non-metallic components without burning.

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Well, the whole point is they're designed not to burn! Under fault conditions, electronic apparatus usually overheats; and the last thing you want it bursting into flames. PCB board, when it gets hot, generally just tends to smoulder a bit and cut off it

Pasta PCB

This reminds me of a story I heard about printing circuits on a sheet of pasta.

Pasta PCB [sciencemuseum.org.uk]

Once the protective coating is removed, the board quickly biodegrades, and the ICs and metal coatings can be easily reclaimed.

And here's a Pretty pasta picture [bbc.co.uk]

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Eeeeeek!

I repeat, Eeeeeek!

All those lovely cancer causing fumes, sure we don't release them because we turn them into building materiel.

But... What happens when your neighbor's house built of this stuff catches fire? Sure, it's not something that h

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But... What happens when your neighbor's house built of this stuff catches fire? Sure, it's not something that happens often on the time scale of an individual, but when you consider the number of buildings as a whole, buildings burning down happen

That's better.

I was getting tired of all the fear-mongering with regard to China. It's nice to see the editors pull up something positive about our neighbors to the East.

-FL

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"I was getting tired of all the fear-mongering with regard to China."

The copper reclaimed from the circuit boards is being machined into shaped charge projectiles by the Sino-Jihadist Internationale, a shadowy Islamo-Maoist group. Just when we thought the

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Wait, come back! I'd like to hear from whoever modded this "Flamebait" which part of the joke they didn't get. I don't care about the moderation, but WTF?

How about...

someone recycling PHB's. Preferably into something useful.

Recycling

Only a small numbers of PCBs are currently recycled.
Large quantities are being shipped to China for stripping of components and recovery of the copper. Especially now the copper price is so high. So I don't believe just a small number is being recycled - i

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Large quantities are being shipped to China for stripping of components and recovery of the copper. Especially now the copper price is so high. So I don't believe just a small number is being recycled - in the USA maybe, but not world wide!

Another thing

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I think the Chinese government's concern is not unjustified.

http://www.chinadaily.com.cn/english/doc/2005-05/ 2 4/content_445129.htm [chinadaily.com.cn]

Hi-tech waste being smuggled into China has caused big pollution because the method used to recycle them. Recycling is a

China and Tiananmen Square

People who dislike China tend to mention Tiananmen Square a lot, but they always forget the Tank Man is also a Chinese.

Some who like China also talk of Tiananmen Square [wikipedia.org], as well as how 2 million Nationists Chinese led by Chiang Kai-shek [wikipedia.org] invaded and subj

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Get your facts straight first if you want convince people you actually know what you're talking about.

The population of Taiwan IS about 23 million at the moment, minus 2 million mainland immigrants - that's 1 million. Are you saying after 60 some years si

Formosa and Mao

Get your facts straight first if you want convince people you actually know what you're talking about.

I did not provide any facts I didn't include a link to where I got the data.

The population of Taiwan IS about 23 million at the moment, minus 2 milli

PCBs

PCBs - You mean printed circuit boards? It'd also be nice if we could recycle polychlorinated biphenyls (or if the Linux kernel could recycle process control blocks).

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It would be nice if we could just keep polychlorinated biphenyls out of the environment in the first place.

Prediction

We will be mining the landfills as soon as it becomes economically feasible. I think this will happen within a decade or so. They're full of tons of stuff we threw away before extracting all of the usefulness. It's metal-rich sludge full of useful organic matter to power the nanodigesters (or whatever we have to invent).

Not that you shouldn't recycle your aluminum and steel cans today.

Digging up the landfill years later

is not a good idea if the toxic waste has already polluted soil and underground water system.

Re:Prediction

Me too, but most with regard to all of the barely used nuclear fuel rods languishing at reactors all over the country. There's a ton of energy left in them, and by burning up the actinides you're left with waste that's 'hot' for a faction of the time. From this Wikipedia article [wikipedia.org]:

Compared to current light-water reactors with a once-through fuel cycle that uses less than 1% of the energy in the uranium, the IFR has a very efficient (99.5% usage) fuel cycle.

and

Another important benefit of removing the long half-life transuranics from the waste cycle is that the remaining waste becomes a much shorter-term hazard. After the actinides and transuranics are removed from the spent fuel, the remaining waste elements have half lives of a few decades at most. The result is that within 300 years, such wastes are no more radioactive than the ores of natural radioactive elements.

This interview [nationalcenter.org] with George S. Stanford, Ph.D highlights the history and potential on IFR's.

fast breeder reactors

Me too, but most with regard to all of the barely used nuclear fuel rods languishing at reactors all over the country. There's a ton of energy left in them, and by burning up the actinides you're left with waste that's 'hot' for a faction of the time.

IE

UK WEEE requires electroincs recycling soon.

I'm currently trying to make sense of the WEEE regulations. UK businesses that supply electronic products are required to register with a waste collection and recycling scheme by the 15th of march if they fall into vaguely defined categories covering most consumer products and some other stuff. A few months after that suppliers have to start taking back unwanted electronics.

The intention is the push the costs of disposal back to the manufacturer.
A director of a UK manufacturing company told me recently that the extra costs for him amount to 18% of turnover for no practical benefit.

It seems to be a full employment scheme for lawyers and beaurocrats. After reading lots of conflicting information on the web I tried reading the act of parliament that implements the European directive and was even more confused and outraged afterwards.
I'm sure there are lots of cases where people can argue over whether their product falss into the vaguely defined categories.

This is on top of CE marking, EMC, and ROHS. I'v seen companys discontinue products because it is just not worth the cost of redesigning to not use lead solder and other non-rohs stuff. With WEEE on top niche market electronics manufacturers just took a big hit.
Consideirng how easy it is to buy very very cheap, non-CE marked electronics direct from Hong Kong via ebay I worry about whats left of UK electronics manufacturing. It's been decimated by pacific rim competition over the last ten years already.

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A director of a UK manufacturing company told me recently that the extra costs for him amount to 18% of turnover for no practical benefit.

No practical benefit? I'd think that proper disposal and recycling of his company's products is a practical benefi

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The one thing that really gets to me about modern electronics, in particular LCD screens for laptops, is the fragility of the fluorescent tube, and that there is no simple way of replacing this component if it breaks.

The actual component cost is around $80

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The actual component cost is around $80, but combined with the LCD screen itself amounts to $1200

Considering that you can buy brand new laptops for ~$600 today I doubt the LCD screen costs that much anymore.

Still, I imagine that there are alignment issues

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Considering that you can buy brand new laptops for ~$600 today I doubt the LCD screen costs that much anymore.

Replacement LCD unit (16TFT-UXGA-HIXS) for a Sony laptop from NextTronics (Sony's component supplier)

Product listing [nexttronicsparts.com]

Price $699.95
Core Charge: $755

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A dell inspirion starts at $599. [dell.com]

But you're talking about retail vs OEM. It's kinda like how a car is actually worth more parted out than sold as a single unit.

It's probably also a much better unit than the 15" model on the $600 laptop.

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Talk about violating the idea of saving the enviroment...

My training:
Reduce - If you don't need to use 2 gallons, don't. If possible, use a friendlier substance over an unfriendly one. IE soap & water rather than a petrol based cleaner
Reuse - If it's

High-Temperature Furnaces

Why not feed the waste into a high-temperature furnace, like those used to rip apart toxic chemical compounds into more benign elements and compounds?

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From TFA:

Only a small numbers of PCBs are recycled. They are typically put into copper smelters, which risks releasing harmful toxic fumes. Most circuit boards are simply incinerated or thrown into landfill, which releases toxic pollutants such as heavy m

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I'm not a chemical engineer, but I believe the furnaces used for neutralizing toxic materials run at substantially higher temperatures that the typical metal smelter.

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Sure, but to generate the heat needed to sustain such high furnace temperature you've got to burn a large amount of fossil fuel. Note the carbon footprint I mentioned.

Also, heavy metals are not consumed by burning. Think about the pollution when it's esca

PCB office supplies?

It would be great to extract the metals and save the plastic with tracings, then we can make computer cases, notepad covers, desk veneers, and other office supplies out of it.

PHBs?

I first read that as 'Recycling PHBs' ... now that is something I would REALLY like to see, because lord knows I need a new boss!

Board solder melts at 260C

It's no mystery that circuit boards are produced by soldering the pieces together. If the parts can be soldered they can certainly be de-soldered as well. Instead of smashing the pieces, why not just slowly heat the boards to the point at which the solder

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Sure, we can mash up some circuit boards and make something. Burning them is silly.

Tell that to the poor people that are doing just that. http://cities.expressindia.com/fullstory.php?newsi d=81450 [expressindia.com] I saw a documentary about it a few years ago, people mel

Follow up

I happened to find a good story with a few pictures. http://www.ban.org/Library/ghosts_in.html [ban.org]

Here's a choice quote:

Every year Guiyu takes in more than a million tonnes of computer waste, earning its residents, according to mainland press reports, RMB1 billion. All day, every day, mountains of wire and other equipment are burned in Guiyu's streets to obtain copper and other scrap metals. Printed circuit boards are heated over charcoal burners to liberate them of computer chips that might be reusable. The boards are then soaked in acid to extract gold, and the waste dumped alongside or in the nearby Lianjiang River. Printer cartridges are ripped apart for their toner and recyclable aluminium, steel and plastic parts. Cathode-ray tubes are hammered open for their copper yokes.

The result is that the air, land and water on which local people depend have all been poisoned. Local well water is already undrinkable, even after boiling, and fresh supplies must be trucked in from the town of Chan Dim 15 kilometres away. According to the report: "It is extremely likely that due to the presence of PVC or brominated flame retardants in wire insulation, the emissions and ashes from such burning will contain high levels of both brominated and chlorinated dioxins and furans - two of the most deadly persistent organic pollutants. It is also highly likely that cancer-causing polycyclic aromatic hydrocarbons are present in the emissions and ash."

"Compared to the rest of China, this place has more miscarriages," says Doctor Li Fai-ping, who works in the maternity ward at the local Chao Yang Yiu Fai Hospital. "Babies simply die in the wombs. There are several cases a month." She adds that the Government has done nothing to assess the damage being done by the e-waste industry. "No scientists have come here to test the effects [of the pollution on the community]. We are sent to work here, we are scared too." "The fact that nobody knows of the dangers is the most depressing thing," says BAN researcher Jim Puckett, co-author of the report.

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The result is that the air, land and water on which local people depend have all been poisoned. Local well water is already undrinkable, even after boiling, and fresh supplies must be trucked in from the town of Chan Dim 15 kilometres away.

I think the ment

Acronym collision

As usual, no acronym may ever be expanded, nor definition given, nor even enough info to get a clue, in a Slashdot story summary. The summary needs to somehow clarify that we are discussing Printed Circuit Boards, and not PolyChlorinated Biphenyls. Really big difference, and both are environmental/technological issues, but orders of magnitude different in impact.

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Unlike current methods, it can be used to reclaim metals such as copper without releasing toxic fumes into the air.

There's your hint.

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I knew which they were referring to without reading the summary, let alone the article.

Having a narrow field of interest, such as in electronics, one may readily conclude "PCBs" mean "printed circuit boards". However if some knows or has a wider field

Re:separation of metals from printed circuit board

"This is an interesting technique that can be a part of a portfolio of technologies to treat PCBs,"

It didn't say this is THE environment friendly way to treat PCBs. But combined with other methods, it could prove more effective. Note this is only resear