Solvent extraction of iron(III) from hydrochloric acid solution by N,N,N′,N′-tetra-2-ethylhexyldiglycolamide in different diluents

Extraction technology of Fe(III) is important to the low grade ferrous ore processing and decontamination of industrial products such as waste printed circuit boards. The performance of extraction and stripping of Fe(III) from hydrochloric acid with N,N,N′,N′-tetra-2-ethylhexyldiglycolamide (T2EHDGA) in different diluents was studied in order to understand the relationship between the nature of the diluents and their extraction of Fe(III). The extraction efficiency of the extractant toward Fe(III) in different diluents increases in the order: toluene < n-hexane < n-octane < n-dodecane. The effect of hydrochloric acid concentration, chloride ion concentration, extractant concentration and temperature on the extraction distribution ratio of Fe(III) was investigated to determine the thermodynamic parameters and the main extracted species. Spectroscopic data (UV-visible and IR) were used to clarify the extraction mechanism. The interfacial behavior of T2EHDGA in different diluents, in the liquid-liquid (L/L) extraction of Fe(III) from hydrochloric acid solution, was studied to clarify the solvent effect of the diluents. The applicability of T2EHDGA to separate Fe(III) from Cu(II), Ni(II) and Cd(II) solution was also investigated.