Recovery of rare earths from spent FCC catalysts by solvent extraction using saponified 2-ethylhexyl phosphoric acid-2-ethylhexyl ester (EHEHPA)

Recycling spent fluid cracking catalysts for rare earth metal recovery: A review

“…However, with n-octane and added TBP, a high extraction is possible even at low pH; this extraction was extremely selective to the REEs with no Al being co-extracted. Saponification, as demonstrated in Ye et al, (2017), leaded to very high extraction, but not selective to REEs; under these conditions, all Al was also co-extracted. Stripping performance varies with the different studies, likely a reflection of the different quantities being extracted in the first stage of the process.…”

Challenges and opportunities for sustainable valorization of rare earth metals from anthropogenic waste

“…The author has also compared the extraction efficiency of D2EHPA and HEHEHP (2-ethylhexylphosphonic mono-2-ethylhexyl ester) and concluded D2EHPA is comparatively a better extractant than HEHEHP in the context of La and Ce recovery from leach liquor of FCC catalyst (Zhao et al 2017 ). Ye et al have reported REM recovery from FCC by solvent extraction using saponified 2-ethylhexyl phosphoric acid-2-ethylhexyl ester (EHEHPA)(Ye et al 2017 ). Ye et al have also followed sequential HCl leaching-solvent extraction using EHEHPA-stripping using the HCl route to recover REM from spent FCC (Ye et al 2017 ).…”

“…Franus et al have reported each ton of coal fly ash could contain 0.1–54 kg/ton of REMs (Franus et al 2015 ). Ferella et al have reported worldwide FCC supply is estimated at 840,000 tons/year (Ferella et al 2016 ; Ye et al 2017 ). Lu et al have reported modern petroleum refining industries are crapping 210,000 tons of FCC annually (Ye et al 2017 ; Lu et al 2020 ).…”

“…Ferella et al have reported worldwide FCC supply is estimated at 840,000 tons/year (Ferella et al 2016 ; Ye et al 2017 ). Lu et al have reported modern petroleum refining industries are crapping 210,000 tons of FCC annually (Ye et al 2017 ; Lu et al 2020 ). All the explained data suggest that efficient recovery of CRMs like REMs from anthropogenic waste is much more important and promising but associated with challenges like lack of industrial-scale valorization process, lack of a clear strategy, road map, policy, effort, funding, and diversified research.…”

Spent FCC E-Cat: Towards a Circular Approach in the Oil Refining Industry

“…Furthermore, aluminum is converted into soluble NaAlO 2 that can be used as secondary raw material. Besides selective precipitation [18], the most used technique for extraction and the further refining of REs from leach liquors is solvent extraction [18][19][20]. Ion-exchange is another hydrometallurgical technique that was used to extract REEs from leach liquors [21][22][23][24].…”