The scientific collaboration between ENEA and Treibacher Industry AG (TIAG) had the aim to develop a novel hydrometallurgical extraction process for the recovery of rare earths, and Yttrium in particular, from waste or other new alternative raw material sources. Research activities were carried out by the two groups using facilities, available laboratories and sharing know-how and skills. Within this cooperation, between 2013 and 2015, ENEA fitted its mission on sustainable development and environmental safety, and TIAG reached an efficient extraction and purification process. Among the tested extraction methods was employed also a bench scale plant, working with supercritical fluids, usually busy for the extraction of natural essences and oils. Supercritical CO2 technique (CO2-SC) is nowadays mostly used to extract organic compounds from vegetal matrices. Recently it has found, in metal extraction, a new application field. CO2-SC assisted metal extractions, usually needs a ligand among which the Ter-n-butyl phosphate (TBP) is one of the most employed. For these applications, among the TBP-based ligands, the ones obtained combining TBP and nitric acid, having the non-specific formula TBP(HNO3)x(H2O)y, often are reported in literature [1-31].
La collaborazione scientifica fra ENEA e Treibacher Industry AG (TIAG) è basata sulla ricerca e ottimizzazione di un processo idro-metallurgico atto ad estrarre e purificare terre rare (in particolare Ittrio) da rifiuti e altri materiali grezzi. Questa ricerca incontra anche gli interessi ENEA in merito alla salvaguardia ambientale e alla sostenibilità. Al fine di traguardare questi comuni interessi, è stato stilato un accordo che ha coronato la proficua collaborazione e lo scambio di conoscenze di due team di ricerca (uno di ENEA e l'altro di TIAG) con le relative apparecchiature nel triennio 2013-2015. Uno dei temi di ricerca ruotava attorno all'uso di fluidi supercritici e complessanti per estrarre e purificare terre rare da varie matrici. L'Anidride Carbonica (CO2) in condizioni supercritiche, finora ampiamente utilizzata per estrarre e concentrare composti organici da matrici vegetali, recentemente ha trovato un nuovo campo di applicazione nell'estrazione dei metalli. Quest'applicazione in genere necessita di un complessante e fra i complessanti più utilizzati figura il Ter-n-butyl phosphate (TBP). In particolare combinando TBP con l'acido nitrico e l'acqua si possono creare diverse tipologie di complessanti la cui formula bruta si può riassumere nella formula generica TBP(HNO3)x(H2O)y spesso riportata in letteratura [1-31].
NOVEL RARE EARTHS EXTRACTION PROCESS BY SUPERCRITICAL CO2 AND TBP-HNO3 COMPLEX (PRELIMINARY EXPERIMENTS) The Treibacher Industries-ENEA experience
2017
Abstract
The scientific collaboration between ENEA and Treibacher Industry AG (TIAG) had the aim to develop a novel hydrometallurgical extraction process for the recovery of rare earths, and Yttrium in particular, from waste or other new alternative raw material sources. Research activities were carried out by the two groups using facilities, available laboratories and sharing know-how and skills. Within this cooperation, between 2013 and 2015, ENEA fitted its mission on sustainable development and environmental safety, and TIAG reached an efficient extraction and purification process. Among the tested extraction methods was employed also a bench scale plant, working with supercritical fluids, usually busy for the extraction of natural essences and oils. Supercritical CO2 technique (CO2-SC) is nowadays mostly used to extract organic compounds from vegetal matrices. Recently it has found, in metal extraction, a new application field. CO2-SC assisted metal extractions, usually needs a ligand among which the Ter-n-butyl phosphate (TBP) is one of the most employed. For these applications, among the TBP-based ligands, the ones obtained combining TBP and nitric acid, having the non-specific formula TBP(HNO3)x(H2O)y, often are reported in literature [1-31].I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
