Obiettivo THE AIM OF THE PRESENT PROGRAMME IS TO DEVELOP ECONOMIC PROCESSES ON THE RECOVERY OF RARE OR STRATEGIC METALS FROM EFFLUENTS, RESIDUES OR SCRAPS. WE WILL STUDY THESE METAL IONS : GERMANIUM AND LANTHANIDES. MOREOVER, THE POSSIBILITY TO REMOVE TWO METAL IONS, SIMULTANEOUSLY WITH ONE LIGAND, FROM A SOLUTION IS ANOTHER VALUABLE ECONOMIC ADVANTAGE. FOR THIS PURPOSE, IT IS NECESSARY TO DEVELOP THE SYNTHESIS AND THE CHARACTERIZATION OF NEW LIGANDS ESPECIALLY DESIGNED FOR CONTEMPORARY COORDINATION OF TWO METAL IONS. THE FEATURES DESIRED IN A LIGAND AND REQUIRED FOR SELECTIVITY CAN BE BUILT INTO MACROCYCLES FORMED THROUGH SCHIFF-BASE REACTIONS USING TEMPLATE OR STEP-BY-STEP TECHNIQUES. The aim of the programme was to develop new processes for the separation and recovery of rare or strategic metals from solutions, especially lanthanides. Some rare earths have been separated and/or concentrated by transferring the experiences gained in liquid liquid extraction to supported liquid membrane technologies, using as carriers macrocyclic or more conventional ligands. The separation of metal ions by supported liquid membranes allows the use of a wide series of sophisticated synthetic ligands. The extraction and stripping processes related to metal separation by membrane techniques have been studied in detail, focusing our interest on the optimisation of best working conditions (particularly the pH range of the loading and receiving phases).MAIN STEPS OF THE PROGRAM WILL BE: 1. PREPARATION OF MACROCYCLIC AND MACROACYCLIC COMPARTMENTAL LIGANDS AND INTRODUCTION IN THE ALIPHATIC CHAIN R, OF ADDITIONAL DONOR ATOMS (S, P, NH, O, ETC.) 2. THE CHELATING PROPERTIES AND THE EXTRACTION SELECTIVITY TOWARDS METAL IONS WILL BE INVESTIGATED. 3. STUDIES TO REMOVE SIMULTANEOUSLY TWO DIFFERENT METALS WITH THE SAME LIGAND, THE TWO METAL IONS WILL BE THEN SEPARATED BY SELECTIVE STRIPPING UNDER APPROPRIATE CONDITIONS. IN ADDITION, THE LIGANDS WILL BE MODIFIED TO INCREASE THE SOLUBILITY OF THE COMPLEXES IN ORGANIC SOLVENTS AND THE TRANSMETALLATION REACTIONS WILL BE EXAMINED CLOSELY. 4. SYNTHESIS OF MACROCYCLES DERIVED FROM KETO-PRECURSORS AND SUBSTITUTED POLYAMINES WILL BE DEVELOPED, TOGETHER WITH THE STUDY OF THE INTERACTION OF THESE MACROCYCLES WITH METAL IONS (TESTING THEIR SEQUESTRATING POWER AND THE STABILITY AND THE REACTIVITY OF THE COMPLEXES ALSO IN TRANSMETALLATION REACTIONS. 5. SEQUESTRATING LIGANDS "OPENED CRIPTANDS" WILL BE PREPARED, THEY CONTAIN PENDANT ARMS AND CAN THUS COORDINATE A METAL ION ALSO IN ITS AXIAL POSITIONS. 6. COMPARISON WITH CRIPTANDS AND CAGES LIGANDS WILL BE CARRIED OUT. IN ADDITION TO THE ABOVE SCHIFF BASES, THE SIMILAR LIGANDS, OBTAINED BY REDUCTION OF THE AZOMETHYNE GROUP WITH SODIUM BOROHYBRIDE OR OTHER REDUCTANTS, WILL BE USED. THE COOPERATION WITH CENTRO RICERCHE VENEZIA (NUOVA SAMIM) AND IRCHA WILL BE BASED IN ORDER OF SETTING UP A LABORATORY MODEL USING LIQUID MEMBRANE TECHNIQUES (NUOVA SAMIM) AND IN IMPROVING THE APPLICABILITY OF LIQUID MEMBRANE IN THE SEPARATION OF GERMANIUM AND LANTHANIDES (IRCHA). MORE IN DETAIL IRCHA AND CENTRO RICERCHE VENEZIA WILL PERFORM THESE PROGRAMS: IRCHA: MEMBRANE EXPERIMENTS: 1. PREPARATION OF SUPPORTED LIQUID MEMBRANES: - CHOICE OF ADAPTED SUPPORT: MATERIAL, THICKNESS POROSITY, PORE SIZE - COMPATIBILITY OF LIQUID MEMBRANE AND POLYMERIC SUPPORT - CONDITIONS OF IMPREGNATION - REPRODUCIBILITY OF PREPARATION. 2. TRANSPORT EXPERIMENTS ON FLAT SHEET MEMBRANE WITH SYNTHETIC REPRESENTATIVE SOLUTIONS. PARAMETER STUDIED: RATE OF METAL TRANSFER - FLUX VALUE, EFFECTS OF PH (FEED AND STRIP), CONCENTRATION (CARRIER, METAL IN FEED), TEMPERATURE, STIRRING RATE - SELECTIVITY WITH RESPECT TO METALS OF INTEREST POSSIBILITY OF COTRANSPORT OF TWO METALS - CONCENTRATION FACTOR IN THE STRIPPING SOLUTION. 3. OPTIMIZATION OF HOLLOW FIBER MODULE (LABORATORY SCALE FOR GE ONLY). FEED: INDUSTRIAL SOLUTION (FOR GE ONLY). FACTORS TO BE OPTIMIZED ARE MAINLY: - FLUX VALUE AND PURITY OF METAL TRANSFERRED - POSSIBILITY OF QUANTITATIVE TRANSFER - LIFE TIME OF THE SLM (METAL FLUX AND SELECTIVITY/TIME) - POSSIBILITY OF REGENERATING SLM. NUOVA SAMIM - CENTRO RICERCHE VENEZIA 1. METHODOLOGIES OF ANALYSIS OF GE AND LANTHANIDES CONTAINED IN THE ORIGINAL SOLUTION AND IN THE PRODUCED PHASE. 2. STUDIES DEVOTED TO THE DEVELOPMENT OF A MODEL PLANT (MEMBRANE REACTOR). Campo scientifico engineering and technologymaterials engineeringfibersnatural scienceschemical sciencesinorganic chemistryalkali metalsengineering and technologychemical engineeringseparation technologiesnatural scienceschemical sciencesinorganic chemistrymetalloids Programma(i) FP1-RAWMAT 3C - Research programme (EEC) on materials (raw materials and advanced materials), 1986-1989 Argomento(i) Data not available Invito a presentare proposte Data not available Meccanismo di finanziamento CSC - Cost-sharing contracts Coordinatore Consiglio Nazionale delle Ricerche (CNR) Contributo UE Nessun dato Indirizzo Corso Stati Uniti 4 35020 Camin Padova Italia Mostra sulla mappa Costo totale Nessun dato Partecipanti (1) Classifica in ordine alfabetico Classifica per Contributo UE Espandi tutto Riduci tutto Institut National de Recherche Chimique Appliquée Francia Contributo UE Nessun dato Indirizzo 91710 Vert-le-Petit Mostra sulla mappa Costo totale Nessun dato
