Lithium

Lithium is one of the lightest alkali metals and highly reactive elements. Its name is derived from the Greek word “lithos”, which means stone. It is extracted from two main sources, i.e., ore mining and salt deserts. Australia is the main source of ore-mined lithium, while Chile and Argentina are well known for salt deserts or salars.

The majority of the world’s lithium is extracted from brine sources, which are found below lakes of high-altitude salt flats. The extraction of lithium involves drilling a hole and pumping brine to the surface with the help of water. The mixture is then left for many months for evaporation. The mixture is then distilled to extract lithium after 12 to 18 months.

The lithium demand has hit record levels in the past few years, and the two key contributors to this rise in demand are:

• An uptrend in digital technology coupled with smart technologies, which are integrated with lithium-ion batteries (LIBs).
• A surge in green energy usage and electric vehicles’ usage.

Lithium mining is often criticised for using excessive water and creating drought-like situations in various parts of the world.

Lithium and its compounds are predominantly extracted from hard rock sources and brine deposits. Historically, hard rock sources were mined, but since the 1990s, brine deposits have been used to produce lithium on a commercial scale. Most of the existing lithium supply comes from hard rock mineral, spodumene, which is found in Australia and the United States, or is being extracted from brine solutions from salars in South America.

Lithium concentration in brine solutions is increased by solar evaporation in ponds. The evaporation process is a time-consuming one and could take up to one-and-a-half years to concentrate the solution to 6% Li content. Thereafter, the brine solution is used to produce high-value lithium compounds, including lithium chloride, lithium carbonate and lithium hydroxide.

With disruptions in the cobalt supply chain, automobile makers are switching to low-cobalt battery chemistries. Low-cobalt cathodes for lithium batteries are anticipated to utilise lithium hydroxide instead of lithium carbonate as a feedstock. Seawater contains over 0.2 parts per million lithium. Some scientists have proposed electrolysis to recover lithium compounds from seawater, but it is not yet commercially viable.