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Separation and purification of Europium and Yttrium from fluorescent powder of spent fluorescent lig

Absrtact	The purpose of this study was to apply the supported liquid membranes with strip dispersion ((SLM-SD) equipment on separation and purification of two rare earth metal ions, europium and yttrium, from fluorescent powder of spent fluorescent lights. In this work, D2EHPA, Isopar-L , and aqueous nitric acid, mixed europium and yttrium nitrate solutions were used to be the extractant, diluent, stripping reagents, and mixed feed solutions respectively in order to evaluate the separation efficiency of the support liquid membranes with strip dispersion processes. Some parameters influencing on the permeability of europium and yttrium ions including the acidity of mixed feed solutions, extractant concentrations, as well as stripping reagent concentrations were investigated in detailed. Results showed as acidity of feed solutions increased, the permeability of europium and yttrium ions increased. Besides, in strong acid condition the permeability of two ions decreased. Additionally, the permeability of europium and yttrium ions was not apparently influenced by the change of extractant concentrations. There was no obvious relationship between stripping reagent concentrations and permeability of europium and yttrium ions. Under these experimental parameters, the goal of 100% separation of europium and yttrium ions can be successfully achieved. The selected parameters for the separation and purification of two rare earth metal ions included inlet europium and yttrium ions concentration at 300 mg/Land 20 mg/L, inlet mixed ion solutions at pH 0.6, concentration of extractant at 15 mM, nitric acid concentration at 2M. Along 90 minutes separation and purification processes, the purification of yttrium ions can be accomplished at 99.9 %. By change the concentration of extractant to 20 mM and inlet mixed ion solutions at pH 1.0, the europium ion can be separate from the remaining mixed solution and reach a purification level of 98.2%. Results of this study can provide useful evidences for further practical applications.
Keyword	separation ＆ purification、fluorescent powder、Europium、Yttrium

Absrtact

The purpose of this study was to apply the supported liquid membranes with strip dispersion ((SLM-SD) equipment on separation and purification of two rare earth metal ions, europium and yttrium, from fluorescent powder of spent fluorescent lights. In this work, D2EHPA, Isopar-L , and aqueous nitric acid, mixed europium and yttrium nitrate solutions were used to be the extractant, diluent, stripping reagents, and mixed feed solutions respectively in order to evaluate the separation efficiency of the support liquid membranes with strip dispersion processes. Some parameters influencing on the permeability of europium and yttrium ions including the acidity of mixed feed solutions, extractant concentrations, as well as stripping reagent concentrations were investigated in detailed. Results showed as acidity of feed solutions increased, the permeability of europium and yttrium ions increased. Besides, in strong acid condition the permeability of two ions decreased. Additionally, the permeability of europium and yttrium ions was not apparently influenced by the change of extractant concentrations. There was no obvious relationship between stripping reagent concentrations and permeability of europium and yttrium ions. Under these experimental parameters, the goal of 100% separation of europium and yttrium ions can be successfully achieved. The selected parameters for the separation and purification of two rare earth metal ions included inlet europium and yttrium ions concentration at 300 mg/Land 20 mg/L, inlet mixed ion solutions at pH 0.6, concentration of extractant at 15 mM, nitric acid concentration at 2M. Along 90 minutes separation and purification processes, the purification of yttrium ions can be accomplished at 99.9 %. By change the concentration of extractant to 20 mM and inlet mixed ion solutions at pH 1.0, the europium ion can be separate from the remaining mixed solution and reach a purification level of 98.2%. Results of this study can provide useful evidences for further practical applications.

Keyword

separation ＆ purification、fluorescent powder、Europium、Yttrium