A comprehensive research program is undertaken to predict the effects of mixing on the extraction efficiency for Co(NO3)2-Di-2-ethylhexyl phosphoric acid in toluene system in mechanically agitated dispersed phase reactors. The experimental and theoretical studies on this complex hydrometallurgical extraction system have yielded the following results. a) A two phase organic and aqueous equilibrium model, which accounts for the aqueous phase equilibria, is developed to predict the distribution of cobalt. The equilibrium model is based on cobalt ion complexation with the DEPHA dimer as suggested by Komasawa et al. . The aqueous phase activities are represented by the Davies Model. b) Physical mass transfer and chemical extraction experiments conducted in a stirred transfer reactor show that the reaction occurs in the aqueous film. A two film diffusion-reaction model is developed to accurately predict the observed fluxes over the experimental range. The composition and temperature ranges for the equilibrium and kinetic experiments are, respectively: a) pH, 3-5; [Co]T, 0.001 to 0.1 M; [DEHPA]2) 0.1 to 1.0 M; T, 25-50°C, and b) pH, 3-5; [Co]T, 0.001 to 0.1 M; [DEHPA]2, 0.01 to 0.5 M; T = 25°C. c) A previously developed Monte Carlo Simulation procedure is employed with the above equilibrium and kinetic models to predict the effect of droplet mixing on extraction efficiency for various process variables. The above experimental and theoretical procedure can be applied to the study of other two phase dispersion systems and can be extended to multiple reactors.
ASJC Scopus subject areas
- Chemical Engineering(all)
- Process Chemistry and Technology
- Filtration and Separation