Lithium (Li) is a highly reactive alkali metal that offers excellent heat
and electrical conductivity. These properties make it particularly useful
for the manufacture of glass, high-temperature lubricants, chemicals,
pharmaceuticals, and lithium ion batteries for electric cars and consumer
electronics. However, because of its high reactivity, pure elemental
lithium is not found in nature but is instead present as a constituent of
salts or other compounds. Most commercial lithium is available in the form
of lithium carbonate, which is a comparatively stable compound that can be
easily converted to other salts or chemicals.
There are two major methods of lithium extraction… Conventional Lithium
Brine extraction and Hard rock / spodumene LiAl(SiO3)2 lithium
These brines contain lithium derived mainly from the leaching of volcanic
rocks and vary greatly in lithium content, largely as a result of the
extent to which they have been subject to solar evaporation.
Highly concentrated lithium deposits in the high altitude salt-flats
known as “salars: found in of Chile, Argentina, Bolivia, Tibet and
China where lithium concentrations can be very high;
Mid-level brines like Silver Peak, Nevada and Searles Lake,
California (a former location of lithium production);
Lower concentration brines like the Great Salt Lake, Utah. The lower
concentration brines have modest evaporation rates and dilution is
constant due to a large volume of fresh water inflow and small lithium
concentrations varying between 30 to 60 ppm.
The effectiveness of producing lithium carbonate from salt brines is so
favourable that most hard rock mining operations have been priced out of
the market with the exception of Australias Greenbushes pegmatite. Lithium
brines are currently the only lithium source that can support mining
without significant other credits from tantalum, niobium, tin etc.
Once the lithium is recovered by-products include saleable compounds such
as potash or boron and the chemicals used can be recycled. Lithium
recovery from brines may lead to a significant carbon footprint reduction
because of a nearly zero-waste mining method.
Lithium brine recovery is typically a straightforward but lengthy process
that can take anywhere from several months to a few years to complete.
drilling/ digging may be required to access the underground salar
brine deposits, and
the brine is then pumped to the surface and distributed to
the brine remains in the evaporation pond for a period of months or
years until most of the liquid water content has been removed through
salar brines are very concentrated and, in addition to lithium,
typically contain potassium and sodium
potassium may be extracted from younger ponds while waiting for the
lithium content to reach a concentration optimal for further
the brine is pumped to a lithium recovery facility for extraction.
This process varies depending upon the brine field composition, but
usually entails the following steps:
Pretreatment -This step usually employs filtration and/or ion
exchange (IX) purification to remove any contaminants or unwanted
constituents from the brine.
Chemical treatment - Next, a series of chemical solvents and
reagents may be applied to isolate desirable products and
byproducts through precipitation.
Filtration - The brine is then filtered to separate out
Saleable lithium production - The brine is finally treated with
a reagent, such as sodium carbonate to form lithium carbonate, and
the product is then filtered and dried for sale. Depending upon
the desired product, different reagents may be applied to produce
other commonly sold forms of lithium, such as lithium hydroxide,
lithium chloride, lithium bromide, and butyl lithium.
Once the lithium extraction process is complete, the remaining brine
solution is returned to the underground reservoir
Over 100 different minerals contain some amount of lithium, however, only
five are actively mined for lithium production. These include spodumene
LiAl(SiO3)2 which is the most common by far, as
well as lepidolite (a purplish form of mica), petalite, amblygonite, and
eucryptite. Spodumene is a pyroxene mineral consisting of lithium aluminum
The process for recovering lithium from ore can vary based on the specific
mineral deposit in question. In general, the process entails removing the
mineral material from the earth then heating and pulverising it. The
crushed mineral powder is combined with chemical reactants, such as
sulphuric acid, then the slurry is heated, filtered, and concentrated
through an evaporation process to form saleable lithium carbonate, while
the resulting wastewater is treated for reuse or disposal.
Beyond salar brine and mineral ore, lithium can be produced from a few
other sources, though such production is not widespread at this time.
These other lithium sources include:
Hectorite clay. Extensive research and development has been invested
into developing effective clay processing techniques, including acid,
alkaline, chloride and sulfate leaching, as well as water
disaggregation and hydrothermal treatment. To date, none of these
technologies has proven economically viable for extracting lithium
Seawater. Hundreds of billions of tons of lithium is estimated to
exist in our oceans, making them an attractive source for meeting
future lithium demand. While existing processes—including a
co-precipitation extraction process and a hybrid IX-sorption
process—have succeeded in extracting lithium from seawater,
Recycled brines from energy plants. Efforts to retrieve lithium from
geothermal brines are gaining popularity as worldwide demand for
lithium increases and as new technologies emerge. The processes used
follow conventional brine extraction, though they might be adapted
based on the content of the brine stream.
Recovered oil field brine. Retrieval of lithium from oil field
brines is technically just another form of conventional brine
extraction, with the difference being the source of the brine.
Recycled electronics. Lithium battery recycling doesn’t truly meet
the definition of extraction, however, as demand grows, lithium ion
battery recycling will become an increasingly valuable source of the
metal. Currently recycling rates are very low at 20%
While each of these poses a potentially valuable source of lithium, the
technologies to extract brine from them are not yet developed enough to
make them cost-effective or viable alternatives to salar brine mining or
mineral ore mining.
Tin was discovered at Greenbushes in 1886 and by 1890 tantalite was being
mined from alluvial ore. Dredges were used to mine placer deposits in the
1960s and ’70s, after which the focus became open-pit mining of weathered
pegmatites. With fluctuations in the tantalum markets, currently only
lithium minerals are mined from the open pits.
The Greenbushes pegmatite is a giant pegmatite dike of Archean age with
substantial Li-Sn-Ta mineralisation, including half the world’s tantalum
This pegmatite swarm was intruded close to, and aligned with, the north to
north-northeasterly-trending Donnybrook-Bridgetown shear zone, a regional
lineament about 150 km long in the Archean Balingup Metamorphic Belt. The
pegmatites at Greenbushes are uncharacteristically fine-grained and
sheared due to the association with the Donnybrook-Bridgetown shear zone.
Most permatites contain large mineral crystals but in the case of
Greenbushes the crystals are somewhat smaller. Its mineral reserve is very
unique grading 50% spodumene LiAl(SiO3)2 This makes
Greenbushes the highest grade lithium mineral resource in the world at
3.9% Li2O mineral reserves and 3.5% Li2O mineral resources versus 1.0 -
2.0% Li2O for other known hard rock deposits.
This highly prospective structural lineament continues for 50km and is
characterised by deformed gneiss, orthogneiss and migmatites.
Australia supplies roughly a third of the world's lithium demand and 75%
of Chinese demand. This gives Australia potentially considerable leverage
against Chinese and other imposed trade sanctions if there is a political
The Greenbushes Lithium Operation has been producing lithium for over 25
years. The mine is located 250 kilometers (km) south of Perth/Fremantle -
a major container shipping port - and 90 km south east of the Port of
Bunbury, a major bulk handling port in Western Australia.
The Greenbushes ore body is a highly mineralized zoned pegmatite with a
strike length of more.than 3 km.
Talison's Greenbushes lithium mineral resource is open along strike and at
depth so there is significant potential to increase lithium mineral
reserves and mineral resources extending the life of mine while at the
same time increasing production rates.
Talison's Greenbushes Lithium Operation produces two categories of lithium
technical-grade lithium concentrates - low iron content for use in
the manufacture of glass, ceramics and heat-proof cookware; and
high yielding chemical-grade lithium concentrate - used to produce
lithium chemicals which form the basis for manufacture lithium-ion
batteries for laptop computers, mobile phones and electric cars.
Talison does not produce lithium chemical products, instead the company
sells lithium concentrate directly to customers for processing into
Spodumene (LiAl(SiO3)2 ) is a pyroxene mineral
consisting of lithium aluminum inosilicate. It occurs as colorless to
yellowish, purplish, or lilac kunzite, yellowish-green or emerald-green
hiddenite, prismatic crystals, often of great size. Concentrates suitable
for lithium carbonate production contain 75-87% spodumene. The typical
impurities in spodumene concentrates are quartz (SiO2), alumina (Al2O3),
and biotite, a solid solution of annite (KFe3AlSi3O10(OH)2) and phlogopite
Under typical (low) temperatures, spodumene is in the α-spodumene form,
which exhibits low reactivity due to its monoclinic structure. Above
800-900°C α-spodumene transforms into β-spodumene, which exhibits
tetragonal structure, thus larger cell volume and Li+-H+ cation exchange
properties. The β-spodumene obtained at temperatures above 900 °C is
therefore reactive and suitable for metallurgical . A brief outline of the
Decrepitation and Sulfation – heated to 1070 degrees celsius to
convert to β-spodumene, cooled and reacted with sulphuric acid to
convert to a lithium sulphate
Neutralisation and Leaching – the lithium sulphate is neutralised
with calcium hydroxide and the solids dewatered and washed (the
liquids - still containing lithium sulphate are recycled), an acid
neutralisation pH 5-6 removes iron and aluminium and a neutralisation
pH 10-11 removes magnesium – the filtrate now contains mostly
dissolvedl ithium sulphate and is reacted with sodium carbonate which
converts 98% to lithium carbonate Li2CO3
Purification – involves cooling and crystallisation of dissolved
lithium carbonate followed by washing nin a rotary vacuum filter
Converting lithium into metal is done in an electrolytic cell using
lithium chloride. The lithium chloride is mixed with potassium chloride in
a ratio of 55% to 45% in order to produce a molten eutectic electrolyte.
Potassium chloride is added to increase the conductivity of the lithium
while lowering the fusion temperature.
When fused and electrolysed at about 449 degrees celsius, chlorine gas is
liberated while molten lithium rises to the surface, collecting in
cast-iron enclosures. The pure lithium produced is wrapped in paraffin wax
to prevent oxidization. The conversion ratio of lithium carbonate to
lithium metal is about 5.3 to 1.
Australia is sunny and windy and we should be energy independent and save
the huge cost of imposed involvement in global energy related conflicts.
The energy is free and cheap, yet we appear to do little to value add by
producing / exporting solar and wind generating equipment.
Abundant renewable electrical energy can easily be collected during the
day. But peak demand for electricity is early evening and most charging of
electric vehicles will take place overnight. Lithium battery storage could
meet this electrical storage need.