Red hot sparks fly through the air as a worker in a heat-resistant suit pokes a long metal rod into a nickel smelter, coaxing the molten metal from a crucible at a processing facility on the Indonesian island of Sulawesi.
The smelter run by global mining firm Vale and powered by electricity from three dams churns out 75,000 tons of nickel a year for use in batteries, electric vehicles, appliances and many other products.
