Singapore sorts valuable metals from PCBs

Scientists at Nanyang Technological University (NTU) in Singapore are pioneering a sorting solution for end-of-life electronics. This could be a huge win for precious metals recovery.  

The NTU’s SCARCE Laboratory has developed a multi-energy X-ray transmission sorter that recognises the metal composition of circuit board components. Project superviser Xia Dong says components can now be automatically screened and classified, thus boosting recovery rates.

Reclaiming small fractions

Dong points out that circuit boards usually contain more than 70 elements. Connectors alone are known to have more than a dozen elements. Meanwhile, many countries across Asia struggle to recycle more than 12% of e-scrap. This means valuable material is lost, especially the small fractions of rare earth elements.

The patented solution can quickly identify even the smallest metallic fractions, according to Dong. This yield recovers valuable materials while notably curbing processing costs.  

Next phase

Further tests are underway to validate the same promising results for lithium-ion batteries, solar panels and e-scrap plastics.

According to the researchers’ estimates, the return on investment for the smart sorter is three years or less. Dong’s team is looking for industrial partners to commercialise the solution by the end of the year. If not, NTU will launch its own start-up.

NTU’s team is also investigating ways to decompose elements that are not commonly recycled. This work includes hydrometallurgy and microfluidics.

The innovation was co-funded by the French Alternative Energies and Atomic Energy Commission R&D group. NTU received academic backing from the Alliance for Research in Circular Economy.