Most of us are aware that old electronics host a range of highly valuable elements which could be retrieved and recycled, but often end up in a landfill.
Electronic waste contains a complex mesh of materials - from copper to gold and platinum - intertwined with toxic hazards such as arsenic and lead. This means we can’t just rip open our old smartphones to easily retrieve what’s valuable.
Instead, the task is entrusted to large-scale processing facilities, so that when you do the right thing and finally take your old iPhone to council e-waste pickup, most likely it will be pre-processed, and end up with tonnes of other electronics exported from Australia as hazardous waste.
If the recycling of electronic waste can be done safely and cost-effectively on a smaller scale, the valuables could instead be used by the local community.
With a vision of overhauling the world’s electronic waste problems, a UNSW research team, lead by Scientia Professor Veena Sahajwalla, has pioneered a highly precise and selective method for retrieving these valuables.
“The world urgently needs a safe, low cost recycling solution for e-waste," says Sahajwalla. "Our approach is to enable every local community to transform their e-waste into valuable metal alloys, instead of leaving old devices in drawers or sheds, or sending them to landfill."
The team has created an innovative microfactory approach - they use a programmed drone that can recognise print circuit boards (PCBs) in a pile of crushed e-waste, and send that information to a robotic arm, which can then safely collect these (watch the video below to see the process in action).
This step ensures that humans are not exposed to potentially hazardous contaminants. Once the robot collects these PCBs, they are fed into a furnace, where precisely controlled temperatures can be used to produce specific alloys for selling on to manufacturers.
Based on the composition of a given circuit board, you can selectively pick the melting strategy, which allows for creating alloys in a tailored manner. Professor Sahajwalla thinks it’s an exciting new way to think about waste - depending on what the trash contains, you can tailor your processing to get the most value out of it.
"The reality is that we don't necessarily need to produce high-purity copper - depending on the application, you might be looking for a copper-nickel alloy, for example."
Professor Sahajwalla envisions a completely transformed e-waste management chain, where a modular microfactory - about the size of a shipping container - could be taken directly to a council e-waste cleanup, without the need to ship the waste elsewhere.
"If factories are so small, you really could be looking at taking the factory to the resource site."
Working on a local scale means a more agile and potentially demand-driven approach to utilising the valuables locked away in our disposable tech. According to Professor Sahajwalla, businesses could choose different waste processing modules based on what kind of alloys they can best sell at a given time period.
"The obvious initial investment has to be in the infrastructure that people need to set up," she explains. "But I cannot image that this solution is more than a few years away."
Professor Sahajwalla is the director of the UNSW Centre for Sustainable Materials Research and Technology, where the microfactory solution is currently in research and development.