The characteristics of aqueous lithium recovery by ion exchange were studied using three commercial cation exchange resins: CMP28 (porous type strong acid exchange resin), SCR-B (gel type strong acid exchange resin) and WK60L (porous type weak acid exchange resin). CMP28 was the most effective material for aqueous lithium recovery; its performance was even enhanced by modifying the cation with K+. A comparison to Na+ and H+ form resins demonstrated that the performance enhancement is reciprocally related to the electronegativity of the cation form. Further kinetic and equilibrium isotherm studies with the K+ form CMP28 showed that aqueous lithium recovery by ion exchange was well fitted with the pseudo-second-order rate equation and the Langmuir isotherm. The maximum ion exchange capacity of aqueous lithium recovery was found to be 14.28 mg/g and the optimal pH was in the region of 4-10.

1. Introduction
 2. Experimental
 3. Results and Discussion
  3.1 Effect of Resin Type
  3.2 Effect of Lithium Ion Concentration
  3.3 Kinetics
  3.4 Equilibrium Isotherm
  3.5 Effect of pH
 4. Conclusion
 References

• Yong Sun Won(Department of Chemical Engineering, Pukyong National University)
• Hae-na You(Department of Chemical Engineering, Pukyong National University)
• Min-Gyu Lee(Department of Chemical Engineering, Pukyong National University) Corresponding author