DEMAND FOR LITHIUM DRIVES NEW EXPLORATION
If you aren't near an electric plug, the chances are that you are relying on lithium. Everything from cell phones, to notebook computers, to medical implants rely on lithium batteries for power. Lithium batteries are rechargeable and store more electricity per pound and cubic inch than other battery types. No wonder, lithium is the metal of the new electrical age. Another lithium product used in high technology electronics is lithium niobate, which is used extensively in telecommunication products like cell phones for such components as resonant crystals. As a result, consumption of lithium totaled 150,000 tons in 2012 and demand for lithium batteries has grown by 25% a year.
Lithium also has other uses. Despite its electrical applications, its largest use remains in the glass and ceramics industry, where lithium oxide is a widely used flux for processing silica, reducing the melting point and viscosity of the material. It's also used for glazes that are less likely to expand when heated. Lithium is also a critical defense material and a key component in powering the Navy's torpedoes. The Mark 50 Torpedo's Stored Chemical Energy Propulsion System (SCEPS) uses a small tank of sulfur hexafluoride gas which is sprayed over a block of solid lithium. The reaction generates heat which is used to generate steam. The steam propels the torpedo in a closed Rankine cycle.
Unfortunately, this domestic demand for lithium isn't matched by domestic mining. Chile is the leading lithium producer, followed by Argentina. Both countries recover the lithium from brine pools. In the United States lithium is recovered from brine pools in Nevada. However, half the world's known reserves are located in Bolivia. Two-thirds of the world production was from brines and one-third from the mining of lithium minerals. Ironically, the industry was once dominated by two major U.S. pegmatite hard rock producers, until Chile started production in the 1980s.
Although the major lithium producers are overseas, there are mines in the US. The Chemetall Foote Lithium Operation in Clayton Valley, Nevada is currently the only operating lithium mine in the United States. There is also Western Lithium, which has the fifth largest lithium deposit in the world - the Kings Valley project in Nevada - which is expected to produce 27,700 tons per year starting in 2014.
The growing demand for lithium has spurred additional exploration in the US, especially in the Southwest. But, lithium isn't as easy to find as some other minerals. That's why another method for exploration is being used by Perry Remote Sensing of Englewood Colorado - satellite imagery. "The best geophysical indicator for lithium is groundwater," said Sandy Perry. She explains that since lithium is leached from certain volcanic rocks, when the surface or groundwater flows into closed basins, the lithium becomes more concentrated.
These "salars" are ideal lithium sources and many junior resource companies are looking at their potential. "The salar setting is much easier to mine and explore," notes Perry. The lithium is recovered after the brine is concentrated by solar evaporation, and the alkalines are removed by precipitation. Lithium carbonate is then removed by adding sodium carbonate. Evaporative brine mining has less environmental impact and very little carbon footprint. It is also much more competitive since a ton of lithium from the evaporative method costs half as much at that recovered through traditional methods.
The problem is finding the lithium in these massive salars. "These things are huge and it takes a long time to get across," Perry notes. They make traditional exploration methods to time consuming.
Perry is using remote sensing data from satellites to find likely lithium deposits. Since lithium is associated with groundwater, Perry uses remote sensing data to find faults and fractures in the geology. As she explains it, these faults have cooler temperatures than the surrounding ground due to higher fluid and vapor flows from groundwater.
Perry is also using the spectral signature of lithium compounds to find these deposits in salars. Some of her work has been in South America. However, there is a lot of potential in the United States. A newly-discovered deposit in Wyoming's Rock Springs Uplift is estimated at 228,000 tons. Additional deposits in the same formation were extrapolated to be as much as 18 million tons.
Some lithium exploration companies are finding interested investors in the automotive industry. Lithium is the preferable technology in rechargeable batteries for hybrid cars. The lithium-ion battery offers higher energy density and can be made into many different shapes, which makes it easier to fit into an electrical device. They also don't have the "memory effect" that makes other rechargeable batteries less attractive. With the growing demand for electric powered cars, the demand for lithium in rechargeable batteries is expected to explode and the auto manufacturers are anxious to secure their supplies. With satellite sensing, maybe they will be able to find them.