Selective separation of Germanium(IV) from simulated industrial leachates containing heavy metals by non-dispersive ionic extraction

Abstract

Germanium can be found in industrial leachates of coal gasification fly ashes or zinc plant residues, containing various heavy metals. In this research, the selective separation of germanium from simulated water coal gasification fly ash leach liquors containing Zn(II), Ni(II), Cd(II), and Co(II) through the flat sheet and hollow fiber supported ionic liquid membrane (FSSLM & HFSLM) systems was developed using an ionic liquid Aliquat 336 as a carrier. As a result, Aliquat-336 was a very fast and effective carrier for the selective transport from these types of solutions. The selective transport of germanium through the mentioned FSSLM system was carried out from a simulated zinc acidic leach liquor containing the aforementioned metals and 0.5 mol/L of H 2 SO 4 under the condition found for the neutral solutions. As a result, an insignificant difference was observed between the germanium transports from both solutions.The germanium transport from both types of solutions was selective and its efficiency reached >98%. Finally, a facilitated transport of germanium was conducted in an HFSLM under the same condition obtained for the FSSLM system. It was observed that this system could transport major amounts of germanium species in the first 30 min showing faster transport than the FSSLM system.

Non-Dispersive Extraction of Ge(IV) from Aqueous Solutions by Cyanex 923: Transport and Modeling Studies

“…Hence, the fluxes at the feed-membrane boundary layer and the membrane phase (Jf and Jm, respectively) can be presented as Eqs. (12) and 13…”

“…Gasification coal fly ashes (GCFAs) containing germanium can be leached with water to dissolve germanium as water-soluble species [5]. Several processes have been developed to recover and separate germanium from impurities such as precipitation [6], flotation [7], ion-exchange [8], distillation [2], adsorption [9], liquid-liquid extraction (LLX) [10], and supported liquid membrane (SLM) [11][12][13]. Among these techniques, the LLX processes have been extensively applied to separate germanium from aqueous solutions [14,15].…”

Non-Dispersive Extraction of Ge(IV) from Aqueous Solutions by Cyanex 923: Transport and Modeling Studies

“…Gasification coal fly ashes (GCFAs) containing germanium can be leached with water to dissolve germanium as water-soluble species [5]. Several processes have been developed to recover and separate germanium from impurities such as precipitation [6], flotation [7], ion-exchange [8], distillation [2], adsorption [9], liquid-liquid extraction (LLX) [10], and supported liquid membrane (SLM) [11][12][13]. Among these techniques, the LLX processes have been extensively applied to separate germanium from aqueous solutions [3,14].…”