The Importance of Lithium
Whether you’ve heard of it or not, almost all of us use lithium in some way or another in our day-to-day lives. Reuters has projected the demands to increase by over five times by 2030 due to the growing use of high-tech devices like electric vehicles and smartphones. Lithium-ion batteries power these devices, providing long-lasting and quick recharge capabilities while remaining lightweight.
It’s important to note that lithium isn’t just used in batteries; it is a key ingredient in producing silica glass and is a common additive in silica dust found in foundries that use sand casting to make casting molds. With the growing demand, it’s crucial to ensure that the supply of this valuable resource continues to meet the increasing needs.
How is Lithium Mined and Processed?
Lithium can be found worldwide but is prevalent in arid regions in the Southern Hemisphere, such as South America and Australia. It is obtained primarily through salt-flat brines and hard rock mining.
Salt-flat brines, which account for around 80% of lithium production, are the primary mining method. Brines are a salty water deposit that occurs in flat, arid regions. Chile, Argentina, and Bolivia, located in the southern hemisphere, are well known for their abundance of brines. This region, known as the “lithium triangle,” is home to over 75% of the world’s supply, buried beneath the vast salt flats.
Lithium from salt-flat brines is processed in 4 steps:
- Pumping: Saltwater is pumped from underground aquifers to the surface and stored in evaporation ponds.
- Evaporation: The water evaporates over time, leaving a concentrated brine solution behind.
- Precipitation: The brine solution is then processed to extract lithium. This process typically involves adding chemicals to precipitate out the lithium salts.
- Filtering and Drying: The salts are then filtered and dried to produce lithium carbonate, the most common form of lithium in batteries.
Hard Rock Mining
Lithium naturally occurs in 145 minerals. But it is primarily extracted from spodumene, lepidolite, petalite, amblygonite, and eucryptite. Though significantly less common than salt-flat brine extraction, this is the second most common method of processing lithium.
Lithium is manually extracted from these minerals in hard rock mining using heavy crushing machinery in five steps:
- Crushing and grinding: The ore is crushed into a fine powder, increasing the ore’s surface area and allowing for more efficient leaching.
- Leaching: The powdered ore leached with a chemical solution to dissolve the lithium. The most common leaching chemicals used for extraction are sulfuric acid and hydrochloric acid.
- Filtering and concentrating: The leached solution is filtered to remove solid particles. The filtered solution is then concentrated to remove any excess water.
- Precipitation: The solution is then treated with a chemical to precipitate out the salts. The most common precipitation chemicals used for extraction are lithium carbonate and lithium hydroxide.
- Filtering and drying: The salts are filtered and dried to produce pure lithium.
The primary problem is sustainability—the amount of water it consumes. Mining one ton of lithium takes about 500,000 gallons of water. Due to the arid nature of premium mining sites, this water consumption can lead to water shortages and droughts in these areas. Hard rock extraction methods can leave mine tailings, negatively impacting local water supplies.
Despite this, it isn’t all bad. At least 90% of the brine water is recycled and returned to the brine, ultimately returning it to the groundwater supply. The process is also relatively efficient and doesn’t consume large amounts of energy.
The minerals and materials within lithium batteries can also be 95% recycled. Even though only about 5% of lithium-ion batteries are currently recycled, solutions are also being developed to recycle EVs and other lithium-ion batteries in larger quantities as demand increases. So, once mined, we can reuse it almost indefinitely. As we obtain and recycle more, we can eventually sustain ourselves with lithium that has already been mined, reducing the need to produce more.
Mine Lithium Sustainably with GK
General Kinematics is committed to developing sustainable and reliable mining solutions. If you’re looking for equipment that can process minerals effectively, contact us, and one of our mining experts will be happy to assist you in optimizing your mining processes.