Abstract
A liquid emulsion membrane (LEM) system for vanadium (IV) transport has been designed using di‐2‐ethylhexyl phosphoric acid (D2EHPA), dissolved in n‐dodecane as carrier. The selection of extractant, D2EHPA, was made on the basis of conventional liquid‐liquid extraction studies. The work has been undertaken by first carrying out liquid‐liquid extraction studies for vanadium (IV) to get stoichiometric constant (n), and equilibrium constant (Kex), which are important for process design.
Transport experiments were carried out at low vanadium (IV) concentration (ppm level). The studies on liquid emulsion membrane included i) the influence of process parameters i.e. feed phase pH, speed of agitation, treat ratio, residence time and ii) emulsion preparation study i.e., organic solvent, extractant concentration, surfactant concentration, internal strip phase concentration. When the strip phase concentration was 2 mol/dm3 (H2SO4) and feed phase pH 3 better extraction of vanadium was obtained. Higher Vm/V1 gave higher extraction of vanadium (IV). A simplified, design engineer friendly model was developed.
Acknowledgement
Suresh V. Yadav is thankful to the University Grants Commission, Government of India, for awarding a Junior Research Fellowship during this investigation. The authors are grateful to Mohini Organics (P) Ltd., Mumbai, India, for the free sample of the surfactant, Monemul 80.