World leader of rare earth based formulations, Solvay is developing numerous innovations used in daily applications (flat screens, energy-saving lamps, automotive exhaust treatment, high precision optical…).

Started in 2007, the project required two years of Research & Development, followed by two years of industrialization, leading to the decision for investment in 2011.


Since Solvay had decided to start recycling energy-saving lamps earlier, the lamp collection system was already in place. These lamps contain six rare earths (Lanthanum, Cerium, Terbium, Yttrium, Europium and Gadolinium), that Solvay now has the capacity to recycle while preserving 100% of their usage performance. End-of-life light bulbs and tubes are collected, sorted and treated by specialized recycling companies that valorize various components (glass, metal, plastic, mercury). The phosphorescent powders (containing the rare earths) are sent to the Solvay plants, first in Saint Fons (France) to produce a first rare earth concentrate, then to La Rochelle (France), which has unique expertise in rare earth purification. Once purified and separated, the rare earths are then formulated to new phosphor precursors that will be reused in the production of new lamps.


Used in small quantities, rare earths are the "vitamins" essential to the development of new technologies, especially green technologies. Global demand for rare earth is growing by more than 6% per year, making it a strategic raw material. “Recycling allows us to develop a new source of supply, and we aim to become the leading European player in that field,"says Du Hua, director of the Rare Earths Global Business Unit of Solvay. "The start of these units reflects the tangible contribution of our profession of chemistry to sustainable development."

The project will initially address recycling phosphor powders contained in energy-saving lamps. Then, the focus will be directed towards other sources of potential waste, for diversification of supplies.


Main activities


The Solvay innovation project showed that the process was extrapolated, but to validate the economical interest at industrial scale, a demonstration is required with the following objectives:

  • Technological validation & process treatment on the demo plant
  • Optimization / development of process equipment at industrial scale
  • Evaluation of the use of alternate waste sources


Expected results


  • Process treatment of more than 1000 tons/year of hazardous wastes
  • Valorization of the stream up to 90% in the form of:

- 10 to 20% of rare earth oxides (Europium, Terbium, Yttrium, etc.)

- 10 to 50% of glass (by product to valorize)

- 70 to 80% of phosphate (by product to valorize)

  • Reduction of wastes by a factor of 10
  • Implementation of an industrial process reusing existing equipment (Saint-Fons & La Rochelle)
  • Processing of more than 3000 tons/year of waste as a project target at the end of the full scale industrialization

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