February 07, 2023

Lithium Extraction: a broad overview

In the current tense global geopolitical climate, western democratic governments are increasingly looking to strengthen their domestic supply chains of metals and minerals deemed "critical" to the economy and particularly to high-tech industries. Of all the critical metals, Ottawa has moved first on lithium, recently ordering select China-based investment groups to sell their positions in Canadian lithium explorers. What makes lithium so special, and how is it made? This article attempts to provide a high-level overview of the journey of lithium from the earth's mantle to its use in powering high-tech industries worldwide.

White gold of the green energy transition

Lithium is the lightest metal known to man and has a high energy density, making it the ideal metal to produce lithium-ion batteries. These batteries are the backbone of all modern electronic devices, from the cell phones in our pockets to the electric vehicles on our streets. The lithium-ion batteries are composed of lithium-cobalt oxide cathodes and graphite anodes, and these cathodes are made of lithium carbonate or lithium hydroxide.

Lithium carbonate is less refined and is usually used in lower-end batteries, while lithium hydroxide is more refined and is used in high-end batteries, like electric vehicles and energy storage systems. If you are looking for exposure to the electric vehicle battery market, make sure to check that the company you are investing in has the capability to produce lithium suitable for lithium hydroxide production.

Where does lithium come from?

Lithium is an element commonly found in the Earth's crust but very rarely is it present in high enough concentrations to make its extraction economically viable. Geologists search for areas where the rocks contain thousands of times more lithium than the average concentrations in the earths crust. These rocks are enriched in lithium (As well as other elements such as Cesium and Tantalum) through a process called fractionation. During this process, as a large, fertile magma chamber cools down and solidifies, some elements prefer to be solid while others remain in a liquid state. Lithium, for example, prefers to stay in its liquid phase until the very last stage of cooling. Because it wants to stay liquid, lithium gets concentrated preferentially into the melt in this magma body, versus other elements like silicon, which don't mind becoming solid.

But what happens when this larger, deeper magma chamber and its remaining melted fraction, instead of completely solidifying, erupts and feeds smaller and thinner intrusions above it? The resulting intrusions, called dykes, are already enriched in lithium and are further enriched through the same process of fractionation as they cool and crystalize. This process can lead to the formation of large, coarse-grained crystals of spodumene, a key ore of lithium. It is through this process of extreme and repeated fractionation of magma that rocks can become concentrated in elements such as lithium and be brought up close enough to the surface of the earth to be minable.

Once the earth has brought the lithium rich ore to the surface, it is typically mined and processed through conventional mining techniques, such as open pit or underground mining, combined with crushing, flotation, and concentration. A typical lithium mine will mill and concentrate ore on site. A concentrate that is adequate for lithium carbonate production will typically be 6-7% Li2O, which usually shipped offsite and processed and refined further.

Letting nature do the work for you

In the previous paragraphs, the process by which lithium is concentrated into ore is described. Hard rock deposits of lithium have been, and still are an important source for lithium. However, in recent years a great deal of development has been done in recovering lithium from brines. A brine is a fluid that contains a high level of dissolved salts; for example, seawater is a brine. Seawater contains dissolved lithium, but in trace amounts. Lithium rich brines are a result of surface or groundwater dissolving lithium in the rocks the water passes through, though further concentration due to evaporation is normally required for the brine to reach a concentration of lithium that is worthwhile to extract. The result is a dry lakebed, which is commonly dry at the surface, but has brine below the surface.

The extraction process for lithium from brines involves pumping the water to the surface and allowing the sun to evaporate the water, leaving behind a concentrated lithium-rich solution. This solution is then processed to extract the lithium, which is then refined and processed into lithium compounds, such as lithium carbonate and lithium hydroxide. The need for a high degree of evaporation to make a brine economical explains why countries like Chile and Argentina account for a large portion of global lithium production: their high altitude, hot temperature environments and large volcanic provinces create the perfect conditions for economic lithium extraction. Other countries, such as the USA and China have similar environments which can produce economic lithium brine.

Untapped resources

Alongside hard rock and lakebed brine deposits, lithium also has the potential to be extracted as a by-product oil and gas field associated brines. Currently there are companies working on proprietary technology to separate lithium out of the wastewater that is produced during the oil and gas extraction process. Oil and gas producers in Alberta currently pump the waste water brine back into the ground, presenting a new potential source of lithium in Canada.

The global demand for lithium-ion batteries is expected to grow exponentially in the coming years, driven by the increasing adoption of electric vehicles and energy storage systems. In fact, the International Energy Agency (IEA) predicts that the number of electric vehicles on the road will increase from 2 million in 2018 to over 250 million by 2030, driving the demand for lithium-ion batteries.

Due to the increasing amount of investment opportunities present in the growing green energy sector, investors are increasingly aware of the need for a better understanding of lithium. Follow us at www.canadianminingreport.com for the latest lithium news.

Share to Youtube Share to Facebook Facebook Share to Linkedin Share to Twitter Twitter Share to Tiktok