A Fundamental Study on the Extraction of Rare Earth Metals using Microcapsules Containing an Extractant

Abstract

As a fundamental investigation of the separation and recovery of rare earth metals from an aqueous solution, the extraction characteristics of lanthanum and cerium have been studied by using microcapsules containing a metal extractant. As the extractant, 2-ethylhexylphosphonic acid mono-2-ethylhexyl ester (EHPNA), was used. The extractant was successfully encapsulated in microcapsules during the in situ microencapsulation process. The extractabilities of the metals into the microcapsules were determined from the extraction isotherms of the metal ions.From the Langmuir model, the saturation amount of metal extracted and the extraction equilibrium constants were determined. The metal extraction rates were also measured using the microcapsules containing EHPNA. As a result, it was shown that the overall extraction process of the metals was controlled by a chelating complex formation reaction between the metal and EHPNA.

Dysprosium sorption by polymeric composite bead: Robust parametric optimization using Taguchi method

“…Removal of Cr(VI) by polysulfone microcapsules containing Cyanex 923 extractant has been reported by Ozcan et al [13]. Kondo with divinyl benzene based microcapsules encapsulating organic extractant [14]. Uranium separation from phosphoric acid solution by bipolymeric microcapsules of calcium alginate containing di-2-ethylhexyl phosphoric acid (D2EHPA) is reported by Outokesh et al [15].…”

“…have been proposed [9][10][11][12], however their adoptability on industrial scale is not that much encouraging. Recently, the use of polymeric beads encapsulating organic solvents has emerged as an effective separation tool over conventional liquid-liquid extraction and ion exchange [13][14][15][16][17][18]. This process has the dual advantage of liquid-liquid extraction and conventional ion exchange in terms of comparatively faster mass transfer rates and higher selectivity.…”

Solvent impregnated carbon nanotube embedded polymeric composite beads: An environment benign approach for the separation of rare earths

“…Kondo et al, have investigated the extraction behavior of rare earths (Nd, Eu, Gd) with divinyl benzene based microcapsules encapsulating organic extractant [15]. Uranium separation from phosphoric acid solution by bipolymeric microcapsules of calcium alginate containing di-2-ethylhexyl phosphoric acid (D2EHPA) is also reported [16].…”