The Application Of Novel Extraction System In Heavy Rare Earth Separation

To resolve the problems in the separation industry of rare earth elements ?REEs?, especially for heavy rare earth elements. In this paper, we researched and developed a series of novel systems for the separation and purification of heavy REEs.The extraction and separation of heavy REE enrichments from ion-adsorbed deposit using Cyanex572 were investigated. The comparison of selectivities for heavy REEs reveals that Cyanex572 is more effective than common industrial extractant P507, especially for the enrichments of Tm, Yb, and Lu. Considering the lower acid requirement and higher stripping efficiency of Cyanex572 than P507, the novel extractant Cyanex572 has revealed industrial application values for the separation of heavy REE enrichments from ion-adsorbed deposit.The novel kind of synergistic extraction using combined ammonium and phosphonium type ionic liquids is reported, which displays pronounced synergistic effect in the extraction of Lu???. The synergistic enhancement coefficients from different mole fractions of [P₆₆₆₁₄][EHEHP] and [N₁₈₈₈][BTMPP] were calculated. Extraction mechanism of the combined functionalized ionic liquids for Lu??? was indicated to be ion association. Thermodynamic constants of the synergistic extraction system were obtained. The loaded Lu??? in the synergistic system could be fully stripped using hydrochloric acid. The new-developed synergistic extraction provides the possibility of separating heavy lanthanides, which reveals theoretical importance and engineering potential for REEs separation.The synergistic effect produced by ionic liquid extractants in the field of adsorption was first reported in this article. The data from this work show that distribution coefficient and synergistic enhancement coefficient of Lu??? extracted by [P₆₆₆₁₄][EHEHP] and [N₁₈₈₈][BTMPP] in impregnated resin are pronounced higher than those in solvent extraction. The synergistic interaction of combined acid-base coupling bifunctional ionic liquids ?ABC-BILs? is the key to the higher adsorption efficiencies of REEs. Moreover, no third phase was observed in the adsorption systems. The elimination of third phase from ABC-BIL is a remarkable advantage of adsorption over solvent extraction in the present study.The synergistic effect produced by functionalized ionic liquids in silica hybrid material for rare earth adsorption is presented in this paper. Interestingly, distribution coefficient Lu??? adsorbed by mixed [P₆₆₆₁₄][EHEHP] and [N₁₈₈₈][BTMPP] in silica hybrid material ?SHM? are pronouncedly higher than their individual contributions. The doped functionalized ionic liquids act as porogens and adsorbents in the SHM. Moreover, the synergistic effect of doped ILs in SHM is indicated to be stable for rare earth adsorption in five recycling. The elimination of third phase from ionic liquid is another remarkable advantage of the SHM over common extraction. Overall, the prepared SHM reveals efficient and sustainable potentials for rare earth adsorption.