Synergistic interplay between D2EHPA and TBP towards the extraction of lithium using hollow fiber supported liquid membrane

ABSTRACT

Extraction of lithium (Li⁺) from synthetically prepared sea bittern using di-2-ethyl hexyl phosphoric acid (D2EHPA) and tri-n-butyl phosphate (TBP) as organic extractants has been studied. The equilibrium studies conducted show synergistic effect between D2EHPA and TBP. The equilibrium constant values for Li⁺, Na⁺ and K⁺ ions were found to be 95.4 × 10⁻⁵ m³/kmol, 4.6 × 10⁻⁵ m³/kmol and 3.69 × 10⁻⁵ m³/kmol, respectively. Hollow fiber supported liquid membrane (SLM) experiments with low concentrations of Li⁺, Na⁺ and K⁺ ions in feed phase showed high flux for Li⁺ ions. However, at significantly high concentrations of Na⁺ and K⁺ in the feed phase, the flux of Li⁺ ions reduced. The model predictions were found to be in good agreement with the experimental data.

KEYWORDS:

• Equilibrium
• HFSLM
• lithium
• metal ion mixture
• model

Funding

The author Ajay D. Sharma would like to thank the Department of Science and Technology (DST) for their financial support by providing fellowship under DST-INSPIRE scheme. The authors would like to thank DST for providing financial assistance to research work through DST project (DST No.: SR/S3/CE/048/2012).