Lithium

Lithium is an element 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. Australia and Chile are the world’s largest producers of lithium.

Type

Element (Minerals/Ores of)

Mineral Classification

Silicate

Chemical Formula

petalite (LiAl(Si2O5)2, lepidolite K(Li,Al)3(Al,Si,Rb)4O10(F,OH)2, spodumene LiAl(SiO3)2

Streak

White, colorless (petalite)

Mohs Hardness

2.5-3 (lepidolite), 6-6.5 (petalite), 6.5-7 (spodumene)

Crystal System

Monoclinic

Color

purple, rosy, silver, gray (lepidolite), grey, pink (petalite), grayish white, pale purple, pale green (spodumene)

Luster

Vitreous, pearly

Fracture

subconchoidal (petalite and spodumene), uneven (lepidolite)

Description

Lithium is an element 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. Australia and Chile are the world’s largest producers of lithium.

Relation to Mining

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.

Lithium resources are detailed in the USGS Mineral Commodities Summaries.

Mining for Lithium:

Lithium is often recovered from brine, or water with a high concentration of lithium carbonate. Subsurface brines trapped in the Earth’s crust are a 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.

Uses

Lithium compounds are used in ceramics and glass, in primary aluminum production, in the manufacture of lubricants and greases, rocket propellants, vitamin A synthesis, silver solders, underwater buoyancy devices, and increasingly in batteries.

Lithium batteries are proving to be an effective and affordable alternative to traditional batteries, and also in new battery applications.  More than 50% of lithium mined is used in batteries.  This use has recently increased rapidly spurring an increase in lithium mining to provide the lithium for batteries.

Lithium is mixed with other light metals such as aluminum and magnesium to form strong, light-weight alloys (an alloy is a mixture of metals).

Some lithium, in the form of lithium carbonate or lithium citrate, is used as medicine to treat gout (an inflammation of joints) and to treat serious mental illness.