Metal extraction from aqueous solution with various organic reactives

Solvent exraction has an importance among separation techniques due to its simplicity, easiness and wide range of use. Therefore, use of solvent extraction method for separation of metal cations can be used not only for chemical analysis but also for production of cations such as Cu+2, Co+2, Ni+2 by means of hydrometallurgical methods in industry.In industry, the recovery of metals from aqueous phase by solvent extraction method, aromatic ß-hydroxy oximes, alkyl hyroxy quinolines, carboxylic acids and amines are examples among compounds used as a ligands.In this study new Schiff Base N,N'-Bis(salicylaldehydene)-1,2-bis-(m -aminophenoxy)ethane was synthesized. The structure of this ligand was confirmed by spectroscopic methods such as UV, IR, 1H NMR, 13C NMR.The other ligand that used in this study is a well known ligand N,N?-ethylenebis(salicylideneimine).The extraction of Cu+2 ion from aqueous phase to organic phase and seperation of Pb+2, Co+2, Cd+2 and Ni+2 ions from Cu+2 ion by using these two ligands.In the first step, the effect of time on extraction was investigated. 15, 30, 45, 60, 75, 90, 105 and 120 minutes were choosen in order to study the effect of time on the exraction. After the extraction process the concentrations of metal ion left in aqueous phase was measured by AAS and the percentages of metal were calculated.In the second step, in order to investigate the effect of pH on the exraction of metal ion with 1,2-MAS and AS ligands, the pH of aqueous phase was changed between 2-13. To provide the consant pH during the exraction buffer solutions were prepared from acetic, phosphoric and boric acids and their potassium salts were used. After the extraction process,the concentrations of metal ion left in aqueous phase was measured by AAS the percentages of extracted Cu(II) were calculated.In the third step, the effect of ligand concentration on the extraction of Cu(II) was investigated and the optimum ligand concentration was determined. After the extraction process, the concentrations of metal ion left in aqueous phase was measured by AAS the percentages of extracted Cu(II) were calculated.In the fourth step, during the extraction of Cu(II) with each ligand the concentration ratio of organic phase to aqueous phase was calculated and the optimum L/M ratio was established. After the extraction process, the concentrations of metal ion left in aqueous phase were measured by AAS and percentage of extracted metal ion were calculated.In the fifth step the salt effect on the extraction of Cu(II) was investigated. Extractions were done using KNO3 and KCl salts. Then the concentration of Cu(II) ion left in aqueous phase was measured by AAS and percentages of extracted metal ion were measured and compared. After that to determine the optimum salt concentration, study was carried out by changing the KNO3 concentration from 0,2 M to 0,9 M. The concentrations of metal ion left in aqueous phase were measured by AAS and percentage of extracted metal ion were calculated.The different concentrations of hydrochloric acid, nitric acid and sulphuric acid were used, ın order to peel off Cu(II) ion from organic phase.By using equation (1,54) which was obtained from the exraction experiments the pH value was ploted against log DM and the linear line was obtained. The combination ratio was calculated from the slope. The log Kex constant was obtained from the Shift value.The separation of metal ions from each other was achieved by solvent exraction method based on pH adjustment. The separation degree, selectivity was expressed as the dispersion ratio of wanted metal to dispersion ratio of unwanted metal. The pH dependent selectivity of Cu+2/Co+2, Cu+2/Pb+2, Cu+2/Cd+2and Cu+2/Ni+2 was calculated from the dispersion ratio of metal between organic and aqueous phase.