ON A CLEAR EVENING at Salar de Uyuni—the world’s largest salt flat, located high in the alpine desert of the Bolivian Andes, and the brightest object on earth when viewed from space—the setting sun cast a huge shadow over a thin layer of rainwater covering the flat. During the day, hundreds of trucks commuted along the flat’s southern rim, while employees of the state-owned mining company Corporación Minera de Bolivia, or Comibol, drilled the salt with enormous rigs. Under large quantities of magnesium and potassium lay the mineral they were after: lithium.
Demand for lithium—a silver metal that has become an essential raw material for electric cars and the batteries of mobile phones and laptops—is booming. In a report last year, the global investment bank Goldman Sachs called it the new gasoline and predicted a three-fold increase in the size of the lithium market by 2025. According to the Bolivian government’s estimates, Salar de Uyuni contains about 70 percent of the world’s lithium; the most optimistic estimates suggest it has reserves of around 100 million tonnes, while the US Geological Survey made a lower estimate of around 9 million tonnes.
Workers transport brine to nearby pools carved out in the middle of the salt flat, some of which are more than a kilometre wide. It is left in the sun for at least three months and then processed into lithium carbonate at Planta Llipi, a factory next to the Rio Grande river. A pilot project inaugurated in 2010 by the Bolivian president, Evo Morales, it produced around 20 tonnes of lithium carbonate in 2016 and is aiming to triple that figure this year. Another lithium factory is expected to be built near the lake by April 2018.