Use of extraction chromatography in the recycling of critical metals from thin film leach solutions

Abstract

Phosphors and optoelectronic thin film electronic device layers contain critical metals including lanthanides and indium that should be recycled. Solvent impregnated resins (SIRs) containing ( Sn is achieved by elution of In(III) with 2.5M HNO3 and Sn(IV) with 5M acid. La is separated from the other lanthanides by elution of La(III) with 2.5M HNO3 and the remaining lanthanides 2 with 5M acid. The SIR resins can be reused over a series of at least five cycles of loading, stripping, and rinsing to reduce reagent costs and achieve economic critical metal recovery by extraction chromatography.

Process development options for electronic waste fractionation to achieve maximum material value recovery

“…(Hadi et al, 2015, Iannicelli-Zubiani et al, 2017. Chemical methods, however, have been used in successful high-value metal recovery processes (Schaeffer et al, 2017a(Schaeffer et al, , 2017b, and to recover highquality polymers through the removal of BFRs by using ionic liquids (Lateef et al, 2008) and other solvent processes (Schlummer et al, 2016). The successful use of processes based on chemicals relies particularly on the efficient separation of the fractions of WEEE that contain metals to produce feedstocks that can be treated for metal recovery with the minimum use of process chemicals.…”

Recovery of an yttrium europium oxide phosphor from waste fluorescent tubes using a Brønsted acidic ionic liquid, 1‐methylimidazolium hydrogen sulfate

“…Conventional processes to solubilise the RE elements in the phosphor powder and to recover them from solution generally involve the use of aggressive acid or alkali digestion, multi‐stage separation procedures, and the production of large aqueous waste streams which require further treatment . Selective recovery of RE elements from the acid or alkaline digestates can be achieved by a number of processes including: precipitation, solvent extraction, ion exchange, electro‐winning, and chromatography with solvent extraction and oxalate precipitation being the two most commonly reported methods. An acid digestion process has been used, for example, to recover yttrium oxide from a waste phosphor powder in 20% H 2 SO 4 at 90 °C using a solid:acid w/v ratio of 1:5 followed by precipitation of the yttrium as yttrium oxalate.…”

“…The interactions between ionic liquids and lanthanide and actinide elements have, for example, been reviewed by Binnemans . Exploitation of these interactions to RE element separation and recovery processes have been described in a number of studies including: the homogeneous liquid–liquid extraction of Nd(III) by choline hexafluoroacetylacetonate in the ionic liquid choline bis(trifluoromethylsulfonyl)imide; the use of functionalized ionic liquids in the solvent extraction of RE elements; the selective extraction and recovery of rare earth metals from phosphor powders from waste fluorescent lamps using an ionic liquid system; the solid–liquid extraction of yttrium and of RE elements from waste fluorescent tube phosphors on ionic liquid impregnated resins; use of a functionalized ionic liquid in the solvent extraction of trivalent RE metal ions; the use of [Hbet][Tf 2 N]:H 2 O systems in the development of a one‐step process for the separation of light from heavy rare earth elements; the recovery of rare earth elements from simulated fluorescent powder using bifunctional ionic liquid extractants and the use of the mixed IL system ([DMAH][NTf 2 ]):[Bmim][Tf 2 N] to dissolve the RE‐containing mineral, bastnaesite …”

Recovery of Rare Earth Elements (REEs) Using Ionic Solvents

“…Recently, solvent impregnated resins (SIRs) based on DODGAA and [C 1 C 4 im] [NTf 2 ] have been developed for extraction chromatography of lanthanides [122], as well as for the recovery of REEs from leach solutions of thin film phosphors [123]. Another diglycolamic acid (HDEHDGA) has been studied by Rout et al, confirming the potential of this type of extractant in ionic liquid media such as tetraoctylammonium dodecyl sulphate, [N 8888 ] [DS] [124] or methyltrioctylammonium bis (trifluoromethanesulfonyl)imide ([N 1888 ] [NTf 2 ]) [125].…”