Abstract
It was clarified in this paper that the extraction of Cu(II), Co(II) and Ni(II) ions with di-(2-ethyl hexyl) phosphoric acid is not affected by ammonium ion, while the extraction with Versatic Acid 911 is considerably hindered. Theoretical treatment on the solvent extraction in the presence of ammonium ion was developed to predict the extent of hindrance to the extraction by the formation of metal ammine complexes in the aqueous phase. The experimental results are in fairly good accodance with the theoretical values.
