Lithium Harvesting from the Most Abundant Primary and Secondary Sources: a comparative Study on Conventional and Membrane Technologies

Figure 3. 
A schematic diagram summarizing the commonly used techniques for lithium harvesting. 
3. Lithium Recovery from Brines/Seawater 
3.1. Conventional Methods 
Despite intensive technological development, conventional extractions from brines 
have succumbed to too many deficiencies and require careful and systematic adaptations 
for varied brine conditions. In most recent research, these conventional techniques (i.e., 
precipitation, liquid-liquid extraction and adsorption) have been incorporated with mem-
brane technologies to improve Li extracting efficiency and also to reduce the industrial 
carbon footprint, however, they have not been commonly practised in industry. 
3.1.1. Precipitation 
In the 1990s, precipitation was primarily employed to precipitate Li after the removal 
of co-existing ions by applying solar evaporation and various precipitants (Equations (1)–
(5)). Typically, this consists of seven stages (Figure 4) that alter the composition of the 
brine; concentrating or precipitating the brine at each stage. The main ions of interest for 
removal are Mg
2+
and Ca
2+
as the smaller ions (e.g., Na
+
) are readily extracted by evapora-
tion via crystallization [48–50]. 
Figure 3.
A schematic diagram summarizing the commonly used techniques for lithium harvesting.
Table 1.
Summary of strengths and weaknesses of using old conventional methodologies for Li
harvesting from Sea-water brines and LIBs.
Techniques/Processes
Strengths
Weaknesses
Conventional technologies for Lithium extraction from Brines/Seawater
Precipitation
Simple Process, Green energy source
(solar evaporation)
Time-consuming, A high volume of waste
Solvent Extraction
simple, adaptable and
continuous operation
A high volume of waste, expensive
co-agents, highly corrosive solvents,
Toxic material formations
Adsorption
Simple operation, low energy
consumption. Adaptable
Time-consuming, adsorbents are
expensive, powdery and easily degrade
in acid-driven desorption
Electrodialysis
Tailorable for Li production
Time-consuming, hazardous and
corrosive materials