Everyday, lithium powers the devices and technology we need to conduct business, transport goods and people, and communicate with people around the world with the added benefit of protecting our planet's ecosystems.
Some people may find that the green and sustainable promise of lithium clashes with the process of obtaining lithium, as mining methods generally tend to destroy our environment in exchange for the minerals procured.
What is Lithium Brine Extraction?
Simply put, lithium extraction is the process of removing lithium using mining techniques to access underground deposits of brine water and ore made of compounds containing lithium and then using industrial equipment and vehicles designed to assist in mining activities to complete the process.
What is Lithium Brine Used For?
Lithium brine is used to refine and produce commercial grade lithium. The brine is originally found underground, where it must be drilled or blasted for access, and processing the brine occurs in multiple steps.
The majority of lithium brine extraction sites are in the 'Lithium Triangle', or a particular set of salars (or salt flats resembling desert climates) located in the southwestern region of South America.
Lithium Brine Extraction TechNologies
Direct Lithium Extraction
Direct Lithium Extraction is a new technological innovation in the lithium extraction process created by Dr. John Burba (also known as the 'Godfather of Lithium') proving to be the superior lithium extraction technique.
Direct Lithium Extraction uses a radical engineering concept and highly selective absorbent which rejects impurities such as magnesium and calcium.
LOW COST / HIGH EFFICIENCY
The process is very efficient and yields commercial grade lithium. Because of the process's efficiency, it is a low cost solution which requires significantly less start-up capital than other methods.
In fact, Direct Lithium Extraction would be the lowest cost producer of lithium using this proven and proprietary lithium extraction process from lithium baring brines.
Another incentive of the Direct Lithium Extraction process is it's environmental friendliness. Over 90% of the brine water used is recycled back into the salar, which preserves the groundwater supply of nearby residents.
Two other technological processes (reverse osmosis and nanofiltration) have been analyzed for their ability to separate lithium from brine water.
Normally, lithium brines are rich in salt ion content, and the osmotic pressure of water is what links to how much salt we can pack into reverse osmosis and nanofiltration processes. This also has something do with membrane selectivity and stability.
Membrane treatment systems can reliably reach their treatment limits and improve yield with the help of systems which automate the chemical softening process.
Older nanofiltration processes don't separate lithium efficiently without treating the brine preliminarily, like diluting the brine with a significant amount of fresh water.
Lithium Brine Extraction Approaches
Mobile Lithium Brine Extraction
Mobile Lithium Extraction (which utilizes DLE technology) is the superior option when comparing approaches to extracting lithium from brine water resources.
Mobile Lithium Brine Extraction avoids the use of evaporation ponds which not only preserves the environment for nearby inhabitants, but speeds up the process of extraction as well (which saves money and increases production output and efficiency).
Since the technology's highly selective absorbent rejects impurities, it reduces the need for harsh chemical use, which leads to less chemical waste and environmental pollution.
Chemical Precipitation starts by pumping the lithium brine into shallow ponds designed to facilitate the evaporation of the brine, thus concentrating the lithium in the solution. Lime is then added to the concentrated solution to help remove magnesium and sodium carbonate is added to help remove any remaining calcium in the solution.
From here, the concentrated lithium solution goes through a carbonation process, which can be further purified into battery-grade lithium by dissolving the lithium again and implementing an ion exchange process to remove any residual impurities.
Sometimes lithium will be precipitated as lithium phosphate in order to save time, which causes precipitation to occur faster because it has a lower solubility. From here, the lithium phosphate goes through an electrochemical process to produce battery-grade lithium.
Adsorption utilizes lithium selective ion exchange sorbents to produce lithium from brine water. For this process to work, the lithium must be in contact with the sorbents for extended amounts of time. These sorbents are expensive, which require high levels of energy consumption in order to properly extract the lithium.
Recently, a new technique for recovering lithium has been examined, which involves intercalating lithium ions from brine into a cathode from FePO4 to create LiFeO4 in an electrochemical process.
From here, the current is reversed, which converts the LiFeO4 into an anode which lithium can be extracted from.
Solvent Extraction uses an organic phase containing kerosene and an extractant. This process has shown promise in being a useful method of extracting lithium, however, it can also cause significant corrosion to the equipment used which is expensive to maintain or replace.
What's left after this process may also need to be processed further to remove the leached solvent so it can be disposed of safely.
The Future of Lithium Brine Extraction
How we conduct the extraction of lithium and the consequential impacts on the environment will prove to be an important factor for survival in the lithium industry and lithium market, not just in lithium brine extraction, but also in spodumene mining for lithium.
New innovations in lithium extraction technology are proving to satisfy both economic and social needs for sustainability in industrial practices, especially with the technological and environmental advancements of Direct Lithium Extraction.
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