![]() ![]() Read an interview with Federica here.Ĭome to the DEMETER Concluding Symposium in Leuven, Belgium, on 5-7 February 2019, which features a high-quality, “beyond-science-only” programme on rare-earth permanent-magnet motors and the e-mobility revolution. In particular, she has been involved in the development and optimisation of critical raw material (CRM) recovery processes from several types of residues such as WEEE and metallurgical slags. Her main interests are in the field of hydrometallurgy, ionometallurgy and solvometallurgy. The authors acknowledge Relight srl (Rho, Italy) for providing the CRT phosphor powder.įederica Forte is postdoctoral research associate at KU Leuven, Department of Chemistry (SOLVOMET Group). This work has received funding from the European Union’s Horizon 2020 Research and Innovation Programme under Grant Agreement No 680629 (REMAGHIC: New Recovery Processes to produce Rare Earth-Magnesium Alloys of High Performance and Low Cost) (project website: ). Graphical abstract: An integrated flow sheet based on roasting and leaching with organic acids is proposed for rare earths recovery from CRT phosphors.įederica Forte, Lourdes Yurramendi, José Luis Aldana, Bieke Onghena and Koen Binnemans, Integrated process for the recovery of yttrium and europium from CRT phosphor waste, RSC Adv. Rare earths are finally precipitated with oxalic acid giving a mixed Y/Eu oxalate which is transformed, after calcination, in the corresponding mixed oxide. Yttrium and europium are recovered from the leaching residue by a second leaching step with methanesulphonic acid (CH 3SO 3H, MSA), another green solvent known for its characteristics of biodegradability, thermal stability and low toxicity. In the second step, the green solvent acetic acid (CH 3COOH, AcOH) is used to dissolve zinc oxide, giving access to the rare earth-rich fraction of the waste powder. The first step of the recovery process is a roasting step at relatively high temperature (850 ⁰C) to oxidise the zinc sulphide to zinc oxide. In this paper, we propose an alternative approach for the recovery of yttrium and europium from waste CRT powder, which overcomes these issues by making use of an integrated process. New process to recover Y and Eu from waste CRT powder The current treatment technologies for waste CRTs suffer from some disadvantages, such us the use of strong acids for the dissolution of the powder: due to the presence of sulfides, this leaching step cause the release of toxic H 2S gas, unless an oxidizing agent is used. This red phosphor is rich in the rare-earth elements (REEs) yttrium and europium and should be regarded as a potential secondary resource for these critical raw materials. ![]() One of the main components of a CRT is the panel glass, which is covered by a mixture of luminescent powders for producing images in particular, the blue and green phosphors are based on zinc sulphide (ZnS:Ag for the blue phosphor and ZnS:Cu for the green phosphor), while the red phosphor is europium-doped yttrium oxysulfide (Y 2O 2S:Eu 3+). For this reason, it crucial to find proper treatment solutions for this type of e-waste. Nowadays a large number of CRT devices is being discharged due to the fact that this technology is being replaced by LCDs, LCD/LEDs and plasma discharge displays. (Leuven, )Ĭathode-ray tubes (CRTs) have widely been used in the past in television screens and computer monitors. The work is published in the Journal RSC Advances. Within the EU H2020 REMAGHIC project, a process was developed by KU Leuven & TECNALIA to recover rare earths from CRT phosphor waste based on roasting and leaching with the green solvents acetic acid and methanesulphonic acid. ![]()
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