German researchers have light bulb moment

Researchers at the Karlsruhe Institute of Technology (KIT) are investigating a simpler way to recycle light bulbs. The R&D team hopes to improve the recovery of magnetic particles containing rare earths.

The KIT team is conducting experiments using magnetic field-controlled chromatography to separate phosphors containing rare earths from end-of-life fluorescent lamps.

‘Results demonstrate that with the intrinsic magnetisation of the phosphor particles and a careful choice of process parameters, we can control the separation outcome,’ says Laura Kruger, who led the research.

The work resulted in purities of up to 95.3% and recoveries of 93.6%. The researchers report that aqueous eluent consumption was found to be ‘quite modest’ at 4.1 L/g and contained minimal quantities of non-toxic and biodegradable solvent.

Kruger notes there is a possibility of scaling up the process by increasing the column size or transferring it to continuous processing methods. Doing so could further enhance its practical applicability across industries.

‘Rare earth-containing materials are essential for a wide range of modern technologies and have significant technological and economic importance,’ she observes.

Her team is determined to contribute to the development of more efficient and effective purification processes for rare earth-containing materials.