A bright idea for recycling rare-earth phosphors from used fluorescent bulbs

March 01, 2024

Researchers have devised a novel method based on a magnetized chromatography technique for recycling rare-earth metals from discarded fluorescent bulbs, offering a solution to the challenge of retrieving these valuable materials from electronic waste. The paper is published in ACS Sustainable Chemistry & Engineering.
The team mimicked old fluorescent lamp parts by mixing the phosphor particles from a lamp manufacturer in a liquid solution with nonmagnetic silica oxide and strongly magnetic iron oxide nanoparticles, representing glass and metal components in the bulbs, respectively. Then, when the liquid was injected and flowed through the chromatography column, the phosphors and iron oxide nanoparticles stuck to the magnetized stainless-steel mesh, while the water and silica particles flowed out the other end.   By applying an external magnetic field to a column filled with stainless-steel mesh disks, the researchers were able to separate rare-earth phosphors, crucial components of fluorescent lighting, from other materials present in the bulbs. Finally, the strongly magnetic iron oxide nanoparticles were released from the column when the magnetic field was turned off. The researchers observed that their method recovered 93% of the rare-earth phosphors from the initial mixture that mimicked lamp components.
Further research is needed to refine the process for industrial-scale applications, but the study represents a significant step toward a more efficient and environmentally friendly recycling solution.

From: EurekAlert!