摘要

The pertraction of Dysprosium (Dy) from nitric acid medium through emulsion liquid membrane (ELM) using di-2-ethylhexylphosphoric acid (D2EHPA) as the carrier extractant in kerosene as the diluent has been systematically investigated. The complexation stoichiometric coefficient and equilibrium constant were measured by equilibrium studies. A non-ionic binary mixed surfactant system (Span 85 + Span 80) was used to stabilize the emulsion and the influence of surfactant mixture composition on the pertraction efficiency was studied. Based on the results, the surfactant mixture made of 75% (v/v) Span 85 and 15% (v/v) Span 80 had the best synergistic effect. The effects of surfactant mixture concentration, carrier concentration, stirring speed, pH value of the feed phase, internal phase concentration, treatment ratio and initial Dy(III) concentration in the feed phase on ELM performance were also evaluated. Under the optimum conditions, extraction efficiency and enrichment of 99.6% and 13.21 was achieved, respectively, within 10 min of pertraction time. Furthermore, the effect of internal phase concentration on the stripping performance is examined. It was found that the best nitric acid concentration in the internal phase that conducted to simultaneous maximum stripping (85.22%) and extraction efficiency (99.6%) of Dy(III) in ELM process is 1 M.

  • 出版日期2017-10