Lithium extraction from Chinese salt-lake brines: opportunities, challenges, and future outlook

Abstract

Chinese salt-lake brine is mainly of the magnesium sulfate subtype with a high Mg/Li ratio. To extract high purity lithium chloride from Chinese brine has been a decade-long challenge. This review summarizes the state-of-the-art of lithium extraction from Chinese salt-lake brine.

Increasing lithium extraction performance by adding sulfonated poly (ether ether ketone) into block‐copolymer ethylene vinyl alcohol membrane

“…The morphology transition of different thickness membranes is influenced by the kinetic transport process of the casting solution in the coagulant bath. When the membrane is very thin, the boundary condition for the membranes strongly influences the exchange process between the solvent and water, resulting in a fully sponge‐like structure . When the thickness increases to a certain threshold value, this situation is not valid anymore and formation of finger‐like macrovoids is favoured due to ‘viscous fingering effect’ .…”

“…When the membrane is very thin, the boundary condition for the membranes strongly influences the exchange process between the solvent and water, resulting in a fully sponge-like structure. [24][25][26][27][28] When the thickness increases to a certain threshold value, this situation is not valid anymore and formation of finger-like macrovoids is favoured due to 'viscous fingering effect'. [56][57][58] The enlarged SEM photos of the top skin layer for all membranes showed a nanoporous structure similar to that of the EVAL membrane, 17,19 but no obvious difference was observed (thus not shown here).…”

“…In previous reports, the pros‐and‐cons of various lithium extraction technologies (i.e. chemical precipitation, ion exchange, nanofiltration, electrodialysis and adsorption) have been discussed and we have identified membrane extraction as one of most suitable candidates …”

“…[20][21][22][23] Because of the low concentration of lithium in seawater 24 and its diminishing supply in ore, 25,26 brine containing lithium has become the main source of lithium, particularly in northwest China where lithium chloride (LiCl) and lithium carbonate were the main chemicals. 27 In these regions, environmental issues related to the loss of organic extractant have pushed the search for a green sustainable extraction technology. In previous reports, the pros-and-cons of various lithium extraction technologies (i.e.…”

“…chemical precipitation, 28,29 ion exchange, [30][31][32][33] nanofiltration, 34-36 electrodialysis 37-39 and adsorption [40][41][42] ) have been discussed and we have identified membrane extraction as one of most suitable candidates. 1,27 Commercial ion exchange membranes have been utilized for promotion of ion diffusion in membrane contactors. 6,43,44 However, there is no long-term stability evidence using ion exchange membranes for extraction purposes, although solvent resistance has been significantly improved.…”