Modelling Extraction and Separation of Some alpha-Transition Elements from Acidic Media by Synergic Combinations of Aromatic Polyimines and Micellar Cationic Exchangers

摘要

In this paper is emphasized, taking the extraction and separation by Dinonylnaphthalene sulfonic acid (HDMNS)of ruthenium-rhodium from a nitric acid media and nickel-cobalt from a sulfuric acid media as examples, the quantified chemical equilibria involved in order to elucidate the extraction mechanism. Reactions in aqueous media were investigated within three aspects: kinetics of formation, stability of metal complexes, ionic associations between complexes and mineral anions present in acidic media. This last point explains partly the selectivity of the system. The behavior of HDNNS within extraction conditions, was studied leading to the structure of the micelle and to the quantification of equilibria involved (critical micelle concentration, polymerization constant, etc...). Ligand extraction was studied previously to metal complexes extraction since the general mechanism of the system proceeds as a competitive extraction of cationic species in aqueous media (protonated forms of the free ligand, cationic metal complexes). The modelling of independent extraction of metals was used to predict numerically the behavior of a multicomponent system where few metals are initially in aqueous media. These simulations are in accordance with experimental results. (ERA citation 14:011466)