Hidden under the Salar de Uyuni -- 10,582 km2 of inhospitable salt desert in the Bolivian Andes -- is the largest natural lithium deposit in the world. In February, the Bolivian government inaugurated a battery manufacturing plant, following the opening of its first lithium carbonate extraction plant in 2013. The next challenge: extracting lithium on an industrial scale.
Lithium-ion batteries are used in phones, laptops, tablets and, increasingly, electric cars. According to the US Geological Survey, demand for the chemical grew, on average, by 6.4 per cent a year between 2000-2012; Tesla Motors plans to build a "gigafactory" in the US, capable by 2020 of producing batteries for up to 500,000 vehicles per year. Bolivia is racing to keep up. "A major challenge is improving the chemical process of evaporation and separation of components," says engineer Luis Alberto Echazú, the Bolivian Mining Corporation's manager of national evaporite resources, who is in charge of the lithium extraction project. "Currently this is via solar evaporation, and takes about eight months." Echazú says they hope to have industrial production underway by 2016, creating 30,000 tonnes of lithium carbonate per year.
Despite soaring demand, Bolivia is keeping a tight hold on this resource -- for now, international involvement is restricted to investment alongside the government.
How to refine the lithium salts:
- Brine from the Salar de Uyuni is pumped into open-air pools.
- Over eight months solar evaporation separates the chemical elements.
- The precipitated lithium sulphate crystals are dissolved in water.
- Lime is mixed with the solution to extract remaining magnesium.
- This solution is reacted with sodium carbonate to produce lithium carbonate.