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Recovery of Mercury and Rare Earth Elements from Fluorescent Lamp Phosphors

Idaho National Laboratory

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Technology Marketing Summary

All fluorescent lights contain small amounts of mercury and rare earth metals. There is a need to safely remove and recycle mercury and rare earth elements from used fluorescent lamps in order to keep the valuable and potentially poisonous metals out of the environment and aid the domestic recovery of critical materials. Conventional processes include heating and distillation to volatilize the mercury and do not include an adequate process to refine the individual rare earth components. In order to optimize the recyclability of fluorescent lights a process is needed that doesn't incorporate the volatilization of mercury and a process to refine and seperate the various rare earth elements contained within the phosphor composition.


The invention is an integrated method to more safely seperate and remove mercury and rare earth elements from fluoresecent light bulbs without the need for volatilizing the mercury.

Process steps include:

  1. Separation of the phosphor powder from glass via ultrasonics
  2. Separation of mercury from phosphor powder
  3. Separation of rare earths from phosphor matrix via oxidation/reduction and acid/base mechanisms
  4. Novel on-line method to refine rare earths

 Rare earths are extracted from the phosphor matrix using a supercritical fluid extraction process with carbon dioxide, mineral acids, acid adducts and metal complexing agents. Additional refining to seperate dissolved rare earths into individual fractions is used to provide rare earth products. Each step in the process is integrated and can be run in batch, semi-batch or continuous-flow mode for the recovery of mercury and rare earths.

  • Does not require volatilization of mercury
  • Integrated process to remove and refine rare earths and mercury
  • Can be run as on-line continuous process
Applications and Industries
  • Fluorescent light recycling
More Information

Patent Information

  1. Methods of recovering rare earth elements from a material
  2. Methods of recovering rare earth elements from a material
Patents and Patent Applications
ID Number
Title and Abstract
Primary Lab
Application 20180119251
A method of recovering rare earth elements from a rare earth-containing material comprises contacting the rare earth-containing material with a solution formulated and configured to dissolve rare earth elements from the rare earth-containing material and form a solution including a plurality of rare earth elements dissolved therein. The method further includes exposing the solution including the plurality of rare earth elements dissolved therein to one of a liquefied gas or a supercritical fluid to isolate the rare earth elements from each other. Related methods of removing and purifying rare earth elements from materials and phosphor lamps are also disclosed.
Technology Status
Technology IDDevelopment StageAvailabilityPublishedLast Updated

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