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."

Comments

Bulding materials?

[TubeSteak]

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.

Re:Bulding materials?

[ajs318]

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?

[dido]

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 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. That makes that ingenious technique described in the article all the more useful: it separates the metallic and non-metallic components without burning.

Re:Bulding materials?

[digitalchinky]

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.

Re:Bulding materials?

[Threni]

> 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.

That's better.

[Fantastic Lad]

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

Prediction

[Anonymous Coward]

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.

Re:Prediction

[Muad'Dave]

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:

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 with George S. Stanford, Ph.D highlights the history and potential on IFR's.

Follow up

[Emetophobe]

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

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.

Acronym collision

[Phreakiture]

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.