Recovery of Lithium from Geothermal Brine with Lithium–Aluminum Layered Double Hydroxide Chloride Sorbents

Abstract

We report a three-stage bench-scale column extraction process to selectively extract lithium chloride from geothermal brine. The goal of this research is to develop materials and processing technologies to improve the economics of lithium extraction and production from naturally occurring geothermal and other brines for energy storage applications. A novel sorbent, lithium aluminum layered double hydroxide chloride (LDH), is synthesized and characterized with X-ray powder diffraction, scanning electron microscopy, inductively coupled plasma optical emission spectrometry (ICP-OES), and thermogravimetric analysis. Each cycle of the column extraction process consists of three steps: (1) loading the sorbent with lithium chloride from brine; (2) intermediate washing to remove unwanted ions; (3) final washing for unloading the lithium chloride ions. Our experimental analysis of eluate vs feed concentrations of Li and competing ions demonstrates that our optimized sorbents can achieve a recovery efficiency of ∼91% and possess excellent Li apparent selectivity of 47.8 compared to Na ions and 212 compared to K ions, respectively in the brine. The present work demonstrates that LDH is an effective sorbent for selective extraction of lithium from brines, thus offering the possibility of effective application of lithium salts in lithium-ion batteries leading to a fundamental shift in the lithium supply chain.

Lithium aluminum‐layered double hydroxide chlorides (LDH): Formation enthalpies and energetics for lithium ion capture

“…A recent absorption experiment using Li-LDH has found that 91% of the lithium was recovered from a geothermal brine solution with high selectivity over Na and K ions. 13 This selectivity arises because the larger alkali ions cannot be accommodated in the octahedral sites of the LDH structure. The economic viability of the sorbent is improved through its reversibility.…”

“…It was observed that if LiCl is less than 125 mg/L in the stripping solution, the LDH phase decomposes to the Al(OH) 3 phase. 13 In addition, when the LiCl concentration is more than 360 mg/L, the LDH becomes saturated and no further absorption occurs. 13 In addition to defining the capacity for Li ions, the stability of the LDH phases controls the cycling life and lithium recovery efficiency.…”

“…13 In addition, when the LiCl concentration is more than 360 mg/L, the LDH becomes saturated and no further absorption occurs. 13 In addition to defining the capacity for Li ions, the stability of the LDH phases controls the cycling life and lithium recovery efficiency. 14 The presence of water in the Li-LDH structure may also play an important role in lithium uptake from the geothermal brine and more detailed studies on the role of water in the LDH structure may be needed in the future.…”

Hybrid Cation Exchange Membranes with Lithium Ion‐Sieves for Highly Enhanced Li+ Permeation and Permselectivity

“…Chitrakar et al. found that the adsorption capacity of H 1.33 Mn 1.67 O 4 and H 1.6 Mn 1.6 O 4 reached up to 30.0 mg g −1 . Furthermore, the crystal structure of LMO only matches the size of Li + , giving a distinct “lithium ion‐sieve effect,” that is, the large‐sized Na + , K + , and Ca 2+ cannot enter.…”

“…[23,[28][29][30] During lithium insertion/extraction, the spinel-type of HMO is well maintained, guaranteeing it to be a long-term lithium adsorbent with high selectivity and high adsorption capacity. Chitrakar [31,32] Furthermore, the crystal structure of LMO only matches the size of Li + , giving a distinct "lithium ion-sieve effect," that is, the large-sized Na + , K + , and Ca 2+ cannot enter. Although Mg 2+ shows similar ionic radius to Li + , its hydration free energy is four times of that of Li + .…”