Effect of Operational Conditions on Separation of Lithium from Geothermal Water by λ-MnO₂ Using Ion Exchange–Membrane Filtration Hybrid Process

ABSTRACT

A hybrid system coupling ion exchange and ultrafiltration (UF) was employed to separate lithium from lithium-spiked geothermal water. The effect of process parameters such as adsorbent type, adsorbent dosage, permeate flow rate, and replacement speeds of fresh and saturated adsorbents have been evaluated to determine the efficiency of the hybrid system. According to the results obtained using λ-MnO₂ derived from spinel-type lithium manganese dioxide, the optimal operating conditions to separate lithium from geothermal water were found with powdery λ-MnO₂ with an adsorbent concentration of 1.5 g adsorbent/L solution, replacement rates of fresh and saturated adsorbents of 6.0 mL/min, and a permeate flow rate of 5.0 mL/min. The ion exchange–UF hybrid system providing an advantage to work with very fine particles easily can be considered as a favorable process for the separation of lithium from geothermal water.

KEYWORDS:

• Geothermal water
• hybrid process
• lithium
• ion exchange
• membrane

Acknowledgments

We are grateful to Izmir Geothermal Co. for geothermal water samples. We thank M.Akçay, S.Bunani and E.Altıok for the kind help in lithium analyses by AAS.

Additional information

Funding

This study was financially supported by a grant so-called TUBITAK–JSPS bilateral project (Project number: 214M360).