Subscribe to our free daily newsletters
. 24/7 Space News .




Subscribe to our free daily newsletters



TECH SPACE
Pulverizing electronic waste is green, clean - and cold
by Staff Writers
Houston TX (SPX) Mar 23, 2017


Circuit boards from electronics, like computer mice, can be crushed into nanodust by a cryo-mill, according to researchers at Rice University and the Indian Institute of Science. The dust can then be easily separated into its component elements for recycling. Image courtesy Chandra Sekhar Tiwary/Rice University.

Researchers at Rice University and the Indian Institute of Science have an idea to simplify electronic waste recycling: Crush it into nanodust. Specifically, they want to make the particles so small that separating different components is relatively simple compared with processes used to recycle electronic junk now.

Chandra Sekhar Tiwary, a postdoctoral researcher at Rice and a researcher at the Indian Institute of Science in Bangalore, uses a low-temperature cryo-mill to pulverize electronic waste - primarily the chips, other electronic components and polymers that make up printed circuit boards (PCBs) - into particles so small that they do not contaminate each other.

Then they can be sorted and reused, he said. The process is the subject of a Materials Today paper by Tiwary, Rice materials scientist Pulickel Ajayan and Indian Institute professors Kamanio Chattopadhyay and D.P. Mahapatra.

The researchers intend it to replace current processes that involve dumping outdated electronics into landfills, or burning or treating them with chemicals to recover valuable metals and alloys. None are particularly friendly to the environment, Tiwary said.

"In every case, the cycle is one way, and burning or using chemicals takes a lot of energy while still leaving waste," he said. "We propose a system that breaks all of the components - metals, oxides and polymers - into homogenous powders and makes them easy to reuse."

The researchers estimate that so-called e-waste will grow by 33 percent over the next four years, and by 2030 will weigh more than a billion tons. Nearly 80 to 85 percent of often-toxic e-waste ends up in an incinerator or a landfill, Tiwary said, and is the fastest-growing waste stream in the United States, according to the Environmental Protection Agency.

The answer may be scaled-up versions of a cryo-mill designed by the Indian team that, rather than heating them, keeps materials at ultra-low temperatures during crushing.

Cold materials are more brittle and easier to pulverize, Tiwary said. "We take advantage of the physics. When you heat things, they are more likely to combine: You can put metals into polymer, oxides into polymers. That's what high-temperature processing is for, and it makes mixing really easy.

"But in low temperatures, they don't like to mix. The materials' basic properties - their elastic modulus, thermal conductivity and coefficient of thermal expansion - all change. They allow everything to separate really well," he said.

The test subjects in this case were computer mice - or at least their PCB innards. The cryo-mill contained argon gas and a single tool-grade steel ball. A steady stream of liquid nitrogen kept the container at 154 kelvins (minus 182 degrees Fahrenheit).

When shaken, the ball smashes the polymer first, then the metals and then the oxides just long enough to separate the materials into a powder, with particles between 20 and 100 nanometers wide. That can take up to three hours, after which the particles are bathed in water to separate them.

"Then they can be reused," he said. "Nothing is wasted."

Research paper

TECH SPACE
Groundbreaking process for creating ultra-selective separation membranes
Minneapolis MN (SPX) Mar 17, 2017
A team of researchers, led by the University of Minnesota, has developed a groundbreaking one-step, crystal growth process for making ultra-thin layers of material with molecular-sized pores. Researchers demonstrated the use of the material, called zeolite nanosheets, by making ultra-selective membranes for chemical separations. These new membranes can separate individual molecules based o ... read more

Related Links
Rice University
Space Technology News - Applications and Research


Thanks for being here;
We need your help. The SpaceDaily news network continues to grow but revenues have never been harder to maintain.

With the rise of Ad Blockers, and Facebook - our traditional revenue sources via quality network advertising continues to decline. And unlike so many other news sites, we don't have a paywall - with those annoying usernames and passwords.

Our news coverage takes time and effort to publish 365 days a year.

If you find our news sites informative and useful then please consider becoming a regular supporter or for now make a one off contribution.

SpaceDaily Contributor
$5 Billed Once


credit card or paypal
SpaceDaily Monthly Supporter
$5 Billed Monthly


paypal only

Comment using your Disqus, Facebook, Google or Twitter login.

Share this article via these popular social media networks
del.icio.usdel.icio.us DiggDigg RedditReddit GoogleGoogle

TECH SPACE
Russia to Build First New-Generation 'Federation' Spacecraft by 2021

Two more spacewalks for Thomas Pesquet

Trump's budget would cut NASA asteroid mission, earth science

Aiming Higher: High School Students Build Flight Hardware Bound for Space

TECH SPACE
SpaceX cargo ship returns to Earth

N. Korea's Kim hails engine test as 'new birth' for rocket industry

SpaceX launches EchoStar XXIII comms satellite into orbit

US BE-4 Rocket Engines to Replace Russian RD-180 on Atlas Carrier Rockets

TECH SPACE
Does Mars Have Rings? Not Right Now, But Maybe One Day

ExoMars: science checkout completed and aerobraking begins

Mars Rover Tests Driving, Drilling and Detecting Life in Chile's High Desert

Opportunity Driving South to Gully

TECH SPACE
China Develops Spaceship Capable of Moon Landing

Long March-7 Y2 ready for launch of China's first cargo spacecraft

China Seeks Space Rockets Launched from Airplanes

Riding an asteroid: China's next space goal

TECH SPACE
Globalsat Sky and Space Global sign MoU for testing and offering satellite service in Latin America

A Consolidated Intelsat and OneWeb

UK funding space entrepreneurs

Kymeta and Intelsat announce new service to revolutionize how satellite services are purchased

TECH SPACE
Why water splashes: New theory reveals secrets

Pulverizing electronic waste is green, clean - and cold

Molecular 'treasure maps' to help discover new materials

Researchers use light to remotely control curvature of plastics

TECH SPACE
Fossil or inorganic structure? Scientists dig into early life forms

Gigantic Jupiter-type planet reveals insights into how planets evolve

Operation of ancient biological clock uncovered

Visualizing debris disk "roller derby" to understand planetary system evolution

TECH SPACE
ESA's Jupiter mission moves off the drawing board

NASA Mission Named 'Europa Clipper'

Juno Captures Jupiter Cloudscape in High Resolution

Juno to remain in current orbit at Jupiter




Memory Foam Mattress Review
Newsletters :: SpaceDaily :: SpaceWar :: TerraDaily :: Energy Daily
XML Feeds :: Space News :: Earth News :: War News :: Solar Energy News






The content herein, unless otherwise known to be public domain, are Copyright 1995-2017 - Space Media Network. All websites are published in Australia and are solely subject to Australian law and governed by Fair Use principals for news reporting and research purposes. AFP, UPI and IANS news wire stories are copyright Agence France-Presse, United Press International and Indo-Asia News Service. ESA news reports are copyright European Space Agency. All NASA sourced material is public domain. Additional copyrights may apply in whole or part to other bona fide parties. All articles labeled "by Staff Writers" include reports supplied to Space Media Network by industry news wires, PR agencies, corporate press officers and the like. Such articles are individually curated and edited by Space Media Network staff on the basis of the report's information value to our industry and professional readership. Advertising does not imply endorsement, agreement or approval of any opinions, statements or information provided by Space Media Network on any Web page published or hosted by Space Media Network. Privacy Statement