Natural resources are the foundation for our lives and lifestyles.
What would our lives be like without mining? Imagine a world without transportation such as jet planes or railroads, without communications such as cell phones or radar, without decorative items such as art or jewelry, without buildings such as skyscrapers or parking garages, without defense systems items such as missiles or submarines, without medical care items such as X-rays or surgical tools. We wouldn’t have any of these things without mining and minerals.
Lithium is an element (#3, symbol Li) valuable for the production of glass, aluminum products, and batteries. It is mined from ores of petalite (LiAl(Si2O5)2, lepidolite K(Li,Al)3(Al,Si,Rb)4O10(F,OH)2, spodumene LiAl(SiO3)2 and also subsurface brines. Chile and Australia are the world’s largest producers of lithium with their combined production being greater than 75% of the world’s production.
Mineral Classification: silicates
petalite (LiAl(Si2O5)2, lepidolite K(Li,Al)3(Al,Si,Rb)4O10(F,OH)2, spodumene LiAl(SiO3)2
2.4 (petalite), 3.03-3.23 (spodumene), 2.9-2.9 (lepidolite)
Crystal System: monoclinic
Color: purple, rosy, silver, gray (lepidolite), grey, pink (petalite), grayish white, pale purple, pale green (spodumene)
Luster: pearly, vitreous
Streak: White, colorless (petalite)
2.5-3 (lepidolite), 6-6.5 (petalite), 6.5-7 (spodumene)
Lithium was first discovered in the mineral petalite. Lepidolite and spodumene are other common minerals which contain lithium. Commercial quantities of these three minerals are in a special igneous rock deposit that geologists call pegmatite. In pegmatites, magma cools so slowly that crystals have time to grow very large. Because lepidolite is a type of mica, its crystals grow into long thin sheets.
Identified lithium resources total 5.5 million tons in the U.S and approximately 34 million tons in other countries. Identified lithium resources for Bolivia and Chile are 9 million tons and in excess of 7.5 million tons, respectively. Identified lithium resources for Argentina, China, and Australia are 6.5 million tons, 5.4 million tons, and 1.7 million tons, respectively. Canada, Congo (Kinshasa), Russia, and Serbia have resources of approximately 1 million tons each. Identified lithium resources for Brazil total 180,000 tons.
Mining for Lithium:
Most lithium is recovered from brine, or water with a high concentration of lithium carbonate. Subsurface brines trapped in the Earth’s crust are the major source material for lithium carbonate. These sources are less expensive to mine than from rock such as spodumene, petalite, and other lithium-bearing minerals.
Brine production of lithium begins by first pumping the brine into evaporative ponds. Over 12 to 18 months, concentration of the brine increases to 6,000 ppm Li through solar evaporation. When the lithium chloride reaches optimum concentration, the liquid is pumped to a recovery plant and treated with soda ash, precipitating lithium carbonate, which is then filtrated, dried, and shipped.