Bolivia’s Salar de Uyuni is the world’s largest potential source of lithium, although it is not currently producing. Uyuni has a total surface area of 9,000 to 10,500 km2
and contains a layer of halite with interstitial brine that is enriched
in lithium, potassium, magnesium, and boron. Concentrations of lithium
in this brine are reported in the literature range from 80 ppm to 4,700
ppm. COMIBOL has drilled two test holes, which identified 11 salt-brine
layers separated by clay layers totalling 170 meters in thickness.
Further evaluation is needed to determine the extent of these separate
horizons that could produce lithium economically. A pilot mining and
processing project was started in May 2008. Recent
estimates for Uyuni’s lithium resources range from 0.6 to 9.0 Mt.
Tahil’s estimate is the most conservative, at 0.6 Mt, whereas estimates
by Anstett el al,
Garrett,
Clarke and Harben, Yaksic and Tilton,and Evans (2008), are between 5
and 5.5Mt. Evans (2009) and Risacher and Fritz round out the top end of
the range, at 8.9 to 9 Mt.
Salar de Uyuni
Average
Li concentration map of Uyuni (g/L), average concentrations below 0.03%
circled in red (adapted from Risacher and Fritz 1991).
