Objetivo Solvent extraction technology has been successfully applied to the recovery and purification of metals. As worldwide pressures increase for reductions in existing limits of chemical pollutants in the environment, extraction processes that require the use of considerable amounts of organic solvents are likely to be replaced by those using new materials that are environmentally safer. Attention is drawn to the development of easily recyclable polymers containing ionselective ligands as anchor groups. Methods used for the extraction of copper in Peru are based on the selectivity of oximes for copper. However, these oximes are known to bind aluminium (III), iron (II) and iron (III), all of which are found with copper (II) in ores. The aims of the project are: to investigate ligands which preferentially extract copper (II) over aluminium (III), iron (III) and iron (II) from water into non aqueous media and the development, characterization and extraction properties of new polymeric materials containing copper selective ligands as anchor groups.Recently a new group of macrocyclic ligands known as polyazas have been synthesised which are able to complex with transition metal cations. Among the tetraazacompounds, the 1,4,8,11-tetraazacyclotetradecane shows selectivity for the copper (II) ions. The stability of the complex formed depends on the pH of the solution. By incorporating substituent groups in the external structure of the ligand, the solubility properties can be modified without affecting the complexing properties of the ligand. Thus, the introduction of lipophilic chains in the structure of tetraazacompounds increases their solubility in organic solvents and decreases their solubility in water, making these ligands suitable for extraction purposes. Other ligands currently being investigated are the amides of ethylenediamine tetraacetate. Experiments with the ligand 1,4,8,11-Tetraaza-13-[dodecyl]-cyclotetradecane-12,14-dione using water chloroform as the solvent system give the following results: the ligand is selective for copper; the rate of the extraction process is very fast; the ligand can be easily recovered; the potential of hydrogen (pH) range for the optimal extraction of copper was from 6.3 to 6.8. According to these results, processes are taking place as a result of changes in the pH of the solution. These results are now being analysed and will be published shortly. In addition, a method is being considered for selecting the best solvent to be used for extraction based on enthalpy data for the dissolution of the ligand in each solvent. Programa(s) IC-ISC C - Activity (Euratom, EEC) on cooperation in science and technology, 1984- Tema(s) Data not available Convocatoria de propuestas Data not available Régimen de financiación CSC - Cost-sharing contracts Coordinador University of Surrey Aportación de la UE Sin datos Dirección GU2 5XH Guildford Reino Unido Ver en el mapa Coste total Sin datos
