A review of technologies for direct lithium extraction from low Li+ concentration aqueous solutions

Abstract

Under the Paris Agreement, established by the United Nations Framework Convention on Climate Change, many countries have agreed to transition their energy sources and technologies to reduce greenhouse gas emissions to levels concordant with the 1.5°C warming goal. Lithium (Li) is critical to this transition due to its use in nuclear fusion as well as in rechargeable lithium-ion batteries used for energy storage for electric vehicles and renewable energy harvesting systems. As a result, the global demand for Li is expected to reach 5.11 Mt by 2050. At this consumption rate, the Li reserves on land are expected to be depleted by 2080. In addition to spodumene and lepidolite ores, Li is present in seawater, and salt-lake brines as dissolved Li+ ions. Li recovery from aqueous solutions such as these are a potential solution to limited terrestrial reserves. The present work reviews the advantages and challenges of a variety of technologies for Li recovery from aqueous solutions, including precipitants, solvent extractants, Li-ion sieves, Li-ion-imprinted membranes, battery-based electrochemical systems, and electro-membrane-based electrochemical systems. The techno-economic feasibility and key performance parameters of each technology, such as the Li+ capacity, selectivity, separation efficiency, recovery, regeneration, cyclical stability, thermal stability, environmental durability, product quality, extraction time, and energy consumption are highlighted when available. Excluding precipitation and solvent extraction, these technologies demonstrate a high potential for sustainable Li+ extraction from low Li+ concentration aqueous solutions or seawater. However, further research and development will be required to scale these technologies from benchtop experiments to industrial applications. The development of optimized materials and synthesis methods that improve the Li+ selectivity, separation efficiency, chemical stability, lifetime, and Li+ recovery should be prioritized. Additionally, techno-economic and life cycle analyses are needed for a more critical evaluation of these extraction technologies for large-scale Li production. Such assessments will further elucidate the climate impact, energy demand, capital costs, operational costs, productivity, potential return on investment, and other key feasibility factors. It is anticipated that this review will provide a solid foundation for future research commercialization efforts to sustainably meet the growing demand for Li as the world transitions to clean energy.

Estimates of lithium mass yields from produced water sourced from the Devonian-aged Marcellus Shale

“…However, SW PA wells only generate, on average, 26-38% more Li when considering differences in PW Li concentrations and the uncertainty of the calculations, despite producing approximately two times the PW volume. Further, extraction of Li from PW with high Mg/Li mass ratios (> 6), such as in SW PA, is less efficient and expensive relative to low Mg/Li extraction methods 31 . The low Mg/Li composition of NE produced waters are comparable to salar brines, such as the Atacama brines of Chile, which are favorable to more economical and sustainable evaporative and distillation Li recovery methods 31,32 .…”

“…Further, extraction of Li from PW with high Mg/Li mass ratios (> 6), such as in SW PA, is less efficient and expensive relative to low Mg/Li extraction methods 31 . The low Mg/Li composition of NE produced waters are comparable to salar brines, such as the Atacama brines of Chile, which are favorable to more economical and sustainable evaporative and distillation Li recovery methods 31,32 . As a result, the higher Li yields from SW PA wells may be more costly to extract due to the lower concentrations and reduced treatment efficiencies due to the high Mg/Li nature of these waters.…”

Purification of Lithium Carbonate from Radioactive Contaminants Using a MnO2-Based Inorganic Sorbent

“…Apart from Th and U, the potassium concentration value in the eluate increased by one order of magnitude. Comparatively higher lithium affinity for manganese oxide than H + and K + ions [24], along with the high Li capacity of MnO 2 [25], explain the elution of potassium from the sorbent. To make the MDM sorbent purification method applicable to low-radioactive background experiments, the conditioning procedure and long-term stability of the sorbent were studied further.…”

Sustainable Lithium Recovery from Hypersaline Salt-Lakes by Selective Electrodialysis: Transport and Thermodynamics

“…Further, by avoiding brine evaporation altogether, DLE can be viable for dilute lithium sources. 23 The high Mg 2+ concentrations in salt-lake brines, however, attenuate the extraction effectiveness of DLE, as a result of the comparable solubility products and ionic radii of Li + and Mg 2+ . 1,17,24 DLE methods to isolate Li from a Na-rich mixture typically require the Li + /Mg 2+ ratio of the brine to be greater than approximately 4 to minimize chemical usage for precipitation and/or solvent recovery.…”

“…In DLE, ionic liquids, eutectic solvents, − fractional crystallization, − electrochemical absorption , and chelating agents , are utilized either separately or synergistically to isolate lithium from a multicomponent mixture (e.g., Na + , K + ). Further, by avoiding brine evaporation altogether, DLE can be viable for dilute lithium sources . The high Mg 2+ concentrations in salt-lake brines, however, attenuate the extraction effectiveness of DLE, as a result of the comparable solubility products and ionic radii of Li + and Mg 2+ . ,, DLE methods to isolate Li from a Na-rich mixture typically require the Li + /Mg 2+ ratio of the brine to be greater than approximately 4 to minimize chemical usage for precipitation and/or solvent recovery. , To enhance the selectivity and the atomic efficiency of DLE, the salt-lake brine can be pretreated with membrane processes like nanofiltration (NF) − or electrodialysis (ED) − to eliminate multivalent cations.…”