Verónica Castro-AllendeThis study presents a novel approach to discarded fluorescent bulbs for rare earths recycling, addressing the challenge of limited accessibility to these valuable metals. Published in the ACS Sustainable Chemistry and Engineering journal, the research outlines a magnetized chromatography technique for extracting rare earth-containing particles from used bulbs. Despite the significance of rare earths in modern technologies like microchips and electric vehicles, their recycling poses significant challenges due to their integration into various components and limited presence in antiquated devices. The team’s low-tech method utilizes magnetic fields to capture phosphors, the compounds responsible for the bulbs’ color. By mimicking lamp components and employing magnetic stainless-steel mesh, the researchers achieved a remarkable 93% recovery rate of rare earth phosphors. Although further refinement and scalability are required, this approach marks a significant step towards sustainable rare earth recycling.
Discarded fluorescent bulbs have formerly been recycled for mercury and glass, but researchers have discovered that they can even be recycled for rare earths.
Despite their cultural significance, rare earths, a group of 17 metals, are not yet widely accessible and aren’t easily obtained using current recycling techniques.
A team of researchers has now found a new way to extract somewhat magnetic particles from used fluorescent bulbs that contain unique earths.
The A C S Sustainable Chemistry and Engineering journal provides more information about the magnetized chromatography technique.
Recycling of rare earths has its challenges.
Rare earths are used in several modern technologies, including microchips and electric vehicles, because of their distinctive electrical, electrical, and visual characteristics.
Untapped deposits of these metals are, nevertheless, uncommon.
Additionally, large-scale methods to recycle rare earths from antiquated devices are challenging because the metals are simply present in small amounts and are integrated into various components.
Rare Earths in Fluorescent Bulbs
A thin layer of a bright bulb contains mixtures of unusual earth-based phosphors, which are the components that control the color of a light.
The team wanted to create a low tech method that was simple enough to collect these phosphors because of this. The technique would make the most of the poor electrical properties of the element.
The team made use of a magnetic field.
The researchers applied a magnetic field to a glass chromatography column filled with stacked disks of stainless-steel mesh in their unique earth recycling technique using a wire coil. Therefore, to see if the phosphors could be captured, a demonstration sample was created.
The team got three distinct poorly electrical rare earth phosphors from a lamp manufacturer for the first time. By combining non-magnetic mineral oxide and highly magnetic iron oxide nanoparticles in a solvent solution, they therefore mimicked old fluorescent lamp parts. These served as the bulbs ‘ glass and metal components.
The phosphors and iron oxide nanoparticles stuck to the magnetized stainless-steel mesh when the liquid was injected and flowed through the chromatography column. The other end was where the water and silica particles came from.
Getting rid of the phosphors
By gradually lowering the additional magnetic field’s strength while rinsing the column with liquid, the team removed the phosphors from the column.
When the magnetic field was out, the magnetic iron oxide nanoparticles were released from the column.
Challenges and Achievements: A 93% recovery rate using Unveiling Magnetized Chromatography
The researchers discovered that their method, which mimicked lamp components, recovered 93 % of the rare earth phosphors from the original mixture.
The team believes that their approach is a step forward in rare earth recycling for a more sustainable future even though more work is needed to separate personal rare earths from phosphors and scale the method for business recycling applications.
