ACS Sustainable Chemistry and Engineering<\/a>. <\/em><\/p>\nChallenges with rare earth recycling<\/h3>\n Because of their unique magnetic, electrical, and optical characteristics, rare earths are used in many modern technologies, such as electric vehicles and microchips.<\/p>\n
However, untapped deposits of these metals are rare.<\/p>\n
On top of this, large-scale methods to recycle rare earths from outdated devices are a challenge because the metals are integrated into different components and are only present in small amounts.<\/p>\n
Rare earths in fluorescent bulbs<\/h3>\n Mixtures of rare earth-based phosphors, the substances that contribute to a light\u2019s colour, are found in a thin coating inside the fluorescent bulb.<\/p>\n
Because of this, the team wanted to develop a low-tech method to easily collect these phosphors. The method would take advantage of the elements\u2019 weak magnetic properties.<\/p>\n
The team utilised a magnetic field<\/h3>\n In their rare earth recycling method, the researchers used a wire coil to apply a magnetic field to a glass chromatography column filled with stacked disks of stainless-steel mesh. A demonstration sample was then prepared, which was passed through the column to see if it could capture the phosphors.<\/p>\n
The team first obtained three different weakly magnetic rare earth phosphors from a lamp manufacturer. They then mimicked old fluorescent lamp parts by mixing the phosphor particles in a liquid solution with nonmagnetic silica oxide and strongly magnetic iron oxide nanoparticles. These represented glass and metal components in the bulbs.<\/p>\n
When the liquid was injected and flowed through the chromatography column, the phosphors and iron oxide nanoparticles stuck to the magnetised stainless-steel mesh. The water and silica particles flowed out the other end.<\/p>\n
Removing the phosphors<\/h3>\n The team removed the phosphors from the column by slowly reducing the strength of the external magnetic field while rinsing the column with liquid.<\/p>\n
The magnetic iron oxide nanoparticles were released from the column when the magnetic field was turned off.<\/p>\n
A 93% recovery rate<\/h3>\n The researchers found that their method recovered 93% of the rare earth phosphors from the initial mixture that mimicked lamp components.<\/p>\n
Although more work is needed to separate individual rare earths from phosphors and to scale the method for industrial recycling applications, the team believe that their approach is a step forward in rare earth recycling for a more sustainable future.<\/p>\n","protected":false},"excerpt":{"rendered":"
Discarded fluorescent bulbs have previously been recycled for glass and mercury, but researchers have found that they could also be used to recycle rare earths.<\/p>\n","protected":false},"author":18,"featured_media":44647,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"_monsterinsights_skip_tracking":false,"_monsterinsights_sitenote_active":false,"_monsterinsights_sitenote_note":"","_monsterinsights_sitenote_category":0,"footnotes":""},"categories":[24502],"tags":[24308],"acf":[],"yoast_head":"\n
New method to recycle rare earths from used fluorescent bulbs<\/title>\n \n \n \n \n \n \n \n \n \n \n \n \n\t \n\t \n\t \n \n \n \n \n \n\t \n\t \n\t \n